Angiogenesis promoted by vascular endothelial growth factor: regulation through alpha1beta1 and alpha2beta1 integrins

Integrins in Cardiovascular Health and Disease: Molecular Mechanisms and Therapeutic Opportunities

Cardiovascular diseases, including atherosclerosis, hypertension, and heart failure, remain the leading cause of global mortality, with endothelial dysfunction and vascular remodeling as critical contributors. Integrins, as transmembrane adhesion proteins, are central regulators of cell adhesion, migration, and signaling, playing a pivotal role in maintaining vascular homeostasis and mediating pathological processes such as inflammation, angiogenesis, and extracellular matrix remodeling. This article comprehensively examines the role of integrins in the pathogenesis of cardiovascular diseases, focusing on their dysfunction in endothelial cells and interactions with inflammatory mediators, such as TNF-α. Molecular mechanisms of integrin action are discussed, including their involvement in mechanotransduction, leukocyte adhesion, and signaling pathways that regulate vascular integrity. The review also highlights experimental findings, such as the use of specific integrin-targeting plasmids and immunofluorescence to elucidate integrin functions under inflammatory conditions. Additionally, potential therapeutic strategies are explored, including the development of integrin inhibitors, monoclonal antibodies, and their application in regenerative medicine. These approaches aim not only to mitigate pathological vascular remodeling but also to promote tissue repair and angiogenesis. By bridging insights from molecular studies with their translational potential, this work underscores the promise of integrin-based therapies in advancing the management and treatment of cardiovascular diseases.

Glucose-Regulated Protein 78, via Releasing β-Catenin from Adherens Junctions, Facilitates Its Interaction with STAT3 in Mediating Retinal Neovascularization

Retinopathy due to neovascularization is one of the major causes of vision loss. To understand the mechanisms underlying retinal neovascularization the oxygen-induced retinopathy (OIR) model was used. Two-dimensional gel matrix-assisted laser desorption/ionization time-of-flight/time-of-flight analysis of normoxic and 24-hour post-OIR mice pups' retinas revealed that glucose-regulated protein 78 (GRP78) was one of the several molecules induced by OIR in the retinal endothelial cells (ECs). Vascular endothelial growth factor A (VEGFA) also induced GRP78 expression independent of endoplasmic reticulum stress response in human retinal microvascular endothelial cells, and its depletion reduced VEGFA-induced EC angiogenic responses. Consistent with these observations, EC-specific deletion of GRP78 inhibited OIR-induced retinal neovascularization. GRP78 bound with vascular endothelial-cadherin and released adherens junction, but not Wnt-mediated, β-catenin. β-catenin, in turn, via interacting with STAT3, triggered cyclin D1 expression. Furthermore, depletion of β-catenin or cyclin D1 levels negated VEGFA-induced EC angiogenic responses and OIR-induced retinal neovascularization. EC-specific deletion of GRP78 also suppressed OIR-induced vascular leakage. Studies of upstream signaling indicated that activating transcription factor 6 mediated GRP78 induction in the modulation of VEGFA-induced EC angiogenic responses and OIR-induced retinal neovascularization. Together, these observations revealed that GRP78, independent of its response to endoplasmic reticulum stress, is involved in mediating EC angiogenic responses by VEGFA and retinal neovascularization by OIR. In view of these findings, GRP78 emerges as a desirable target for drug development against diabetic retinopathy.

Integrins regulation of wound healing processes: insights for chronic skin wound therapeutics

Integrins are heterodimers composed of non-covalently associated alpha and beta subunits that mediate the dynamic linkage between extracellular adhesion molecules and the intracellular actin cytoskeleton. Integrins are present in various tissues and organs and are involved in different physiological and pathological molecular responses in vivo. Wound healing is an important process in the recovery from traumatic diseases and consists of three overlapping phases: inflammation, proliferation, and remodeling. Integrin regulation acts throughout the wound healing process to promote wound healing. Prolonged inflammation may lead to failure of wound healing, such as wound chronicity. One of the main causes of chronic wound formation is bacterial colonization of the wound. In this review, we review the role of integrins in the regulation of wound healing processes such as angiogenesis and re-epithelialization, as well as the role of integrins in mediating bacterial infections during wound chronicity, and the challenges and prospects of integrins as therapeutic targets for infected wound healing.

Biomechanical forces and force-triggered drug delivery in tumor neovascularization

Tumor angiogenesis is one of the typical hallmarks of tumor occurrence and development, and tumor neovascularization also exhibits distinct characteristics from normal blood vessels. As the number of cells and matrix inside the tumor increases, the biomechanical force is enhanced, specifically manifested as solid stress, fluid stress, stiffness, and topology. This mechanical microenvironment also provides shelter for tumors and intensifies angiogenesis, providing oxygen and nutritional support for tumor progression. During tumor development, the biomechanical microenvironment also emerges, which in turn feeds back to regulate the tumor progression, including tumor angiogenesis, and biochemical and biomechanical signals can regulate tumor angiogenesis. Blood vessels possess inherent sensitivity to mechanical stimuli, but compared to the extensive research on biochemical signal regulation, the study of the regulation of tumor neovascularization by biomechanical signals remains relatively scarce. Biomechanical forces can affect the phenotypic characteristics and mechanical signaling pathways of tumor blood vessels, directly regulating angiogenesis. Meanwhile, they can indirectly regulate tumor angiogenesis by causing an imbalance in angiogenesis signals and affecting stromal cell function. Understanding the regulatory mechanism of biomechanical forces in tumor angiogenesis is beneficial for better identifying and even taming the mechanical forces involved in angiogenesis, providing new therapeutic targets for tumor vascular normalization. Therefore, we summarized the composition of biomechanical forces and their direct or indirect regulation of tumor neovascularization. In addition, this review discussed the use of biomechanical forces in combination with anti-angiogenic therapies for the treatment of tumors, and biomechanical forces triggered delivery systems.

Integrins and their potential roles in mammalian pregnancy

Integrins are a highly complex family of receptors that, when expressed on the surface of cells, can mediate reciprocal cell-to-cell and cell-to-extracellular matrix (ECM) interactions leading to assembly of integrin adhesion complexes (IACs) that initiate many signaling functions both at the membrane and deeper within the cytoplasm to coordinate processes including cell adhesion, migration, proliferation, survival, differentiation, and metabolism. All metazoan organisms possess integrins, and it is generally agreed that integrins were associated with the evolution of multicellularity, being essential for the association of cells with their neighbors and surroundings, during embryonic development and many aspects of cellular and molecular biology. Integrins have important roles in many aspects of embryonic development, normal physiology, and disease processes with a multitude of functions discovered and elucidated for integrins that directly influence many areas of biology and medicine, including mammalian pregnancy, in particular implantation of the blastocyst to the uterine wall, subsequent placentation and conceptus (embryo/fetus and associated placental membranes) development. This review provides a succinct overview of integrin structure, ligand binding, and signaling followed with a concise overview of embryonic development, implantation, and early placentation in pigs, sheep, humans, and mice as an example for rodents. A brief timeline of the initial localization of integrin subunits to the uterine luminal epithelium (LE) and conceptus trophoblast is then presented, followed by sequential summaries of integrin expression and function during gestation in pigs, sheep, humans, and rodents. As appropriate for this journal, summaries of integrin expression and function during gestation in pigs and sheep are in depth, whereas summaries for humans and rodents are brief. Because similar models to those illustrated in Fig. 1, 2, 3, 4, 5 and 6 are present throughout the scientific literature, the illustrations in this manuscript are drafted as Viking imagery for entertainment purposes.

Matrix stiffness, endothelial dysfunction and atherosclerosis

Atherosclerosis (AS) is the leading cause of the human cardiovascular diseases (CVDs). Endothelial dysfunction promotes the monocytes infiltration and inflammation that participate fundamentally in atherogenesis. Endothelial cells (EC) have been recognized as mechanosensitive cells and have different responses to distinct mechanical stimuli. Emerging evidence shows matrix stiffness-mediated EC dysfunction plays a vital role in vascular disease, but the underlying mechanisms are not yet completely understood. This article aims to summarize the effect of matrix stiffness on the pro-atherosclerotic characteristics of EC including morphology, rigidity, biological behavior and function as well as the related mechanical signal. The review also discusses and compares the contribution of matrix stiffness-mediated phagocytosis of macrophages and EC to AS progression. These advances in our understanding of the relationship between matrix stiffness and EC dysfunction open the avenues to improve the prevention and treatment of now-ubiquitous atherosclerotic diseases.

Primary Cardiac Angiosarcoma: A Review

Primary cardiac angiosarcoma is a rare and aggressive malignancy originating from the endothelial lining of cardiac blood vessels. This review covers various aspects of the disease, including its pathogenesis, clinical presentation, diagnosis, treatment, and prognosis. The primary characteristic of cardiac angiosarcoma is the rapid growth of abnormal blood vessels that invade the heart muscle, leading to the destruction of healthy tissue. Due to its infiltrative nature and early spread, diagnosing and treating cardiac angiosarcoma present significant challenges. Transesophageal echocardiography (TEE) plays a crucial role in diagnosing cardiac tumors such as angiosarcoma due to its high sensitivity. Additional imaging techniques such as computed tomography (CT) and cardiac magnetic resonance imaging (MRI) help assess tumor anatomy and identify metastases. Histopathological examination and immunohistochemistry are essential for confirming the diagnosis, as they reveal distinct histological features and specific endothelial markers associated with primary cardiac angiosarcoma. Targeted therapies directed at the angiogenic mechanisms and molecular abnormalities hold promise for improving treatment outcomes. Early detection of primary cardiac angiosarcoma remains challenging due to its rarity, and the prognosis is generally poor due to advanced disease at the time of diagnosis. The review emphasizes the importance of a multidisciplinary approach and collaboration among different specialties to optimize the diagnosis, treatment, and follow-up care of patients with primary cardiac angiosarcoma. The ultimate goal is to enhance diagnostic methods and therapeutic approaches by advancing knowledge and promoting further research into this aggressive malignancy.

Non-coding RNA regulation of integrins and their potential as therapeutic targets in cancer

BACKGROUND

Integrins are integral to cell signalling and management of the extracellular matrix, and exquisite regulation of their expression is essential for a variety of cell signalling pathways, whilst disordered regulation is a key driver of tumour progression and metastasis. Most recently non-coding RNAs in the form of micro-RNA (miRNA) and long non-coding RNA (lncRNA) have emerged as a key mechanism by which tissue dependent gene expression is controlled. Whilst historically these molecules have been poorly understood, advances in 'omic' technologies and a greater understanding of non-coding regions of the genome have revealed that non-coding RNAs make up a large proportion of the transcriptome.

CONCLUSIONS AND PERSPECTIVES

This review examines the regulation of integrin genes by ncRNAs, provides and overview of their mechanism of action and highlights how exploitation of these discoveries is informing the development of novel chemotherapeutic agents in the treatment of cancer. MiRNA molecules have been the most extensively characterised and negatively regulate most integrin genes, classically regulating genes through binding to recognition sequences in the mRNA 3'-untranslated regions of gene transcripts. LncRNA mechanisms of action are now being elucidated and appear to be more varied and complex, and may counter miRNA molecules, directly engage integrin mRNA transcripts, and guide or block both transcription factors and epigenetic machinery at integrin promoters or at other points in integrin regulation. Integrins as therapeutic targets are of enormous interest given their roles as oncogenes in a variety of tumours, and emerging therapeutics mimicking ncRNA mechanisms of action are already being trialled.

Integrin Targeting Enhances the Antimelanoma Effect of Annexin V in Mice

Malignant melanoma, an increasingly common form of skin cancer, is a major threat to public health, especially when the disease progresses past skin lesions to the stage of advanced metastasis. Targeted drug development is an effective strategy for the treatment of malignant melanoma. In this work, a new antimelanoma tumor peptide, the lebestatin-annexin V (designated LbtA5) fusion protein, was developed and synthesized by recombinant DNA techniques. As a control, annexin V (designated ANV) was also synthesized by the same method. The fusion protein combines annexin V, which specifically recognizes and binds phosphatidylserine, with the disintegrin lebestatin (lbt), a polypeptide that specifically recognizes and binds integrin α1β1. LbtA5 was successfully prepared with good stability and high purity while retaining the dual biological activity of ANV and lbt. MTT assays demonstrated that both ANV and LbtA5 could reduce the viability of melanoma B16F10 cells, but the activity of the fusion protein LbtA5 was superior to that of ANV. The tumor volume growth was slowed in a mouse xenograft model treated with ANV and LbtA5, and the inhibitory effect of high concentrations of LbtA5 was significantly better than that of the same dose of ANV and was comparable to that of DTIC, a drug used clinically for melanoma treatment. The hematoxylin and eosin (H&E) staining test showed that ANV and LbtA5 had antitumor effects, but LbtA5 showed a stronger ability to induce melanoma necrosis in mice. Immunohistochemical experiments further showed that ANV and LbtA5 may inhibit tumor growth by inhibiting angiogenesis in tumor tissue. Fluorescence labeling experiments showed that the fusion of ANV with lbt enhanced the targeting of LbtA5 to mouse melanoma tumor tissue, and the amount of target protein in tumor tissue was significantly increased. In conclusion, effective coupling of the integrin α1β1-specific recognition molecule lbt confers stronger biological antimelanoma effects of ANV, which may be achieved by the dual effects of effective inhibition of B16F10 melanoma cell viability and inhibition of tumor tissue angiogenesis. The present study describes a new potential strategy for the application of the promising recombinant fusion protein LbtA5 in the treatment of various cancers, including malignant melanoma.

The effects of inhibition and siRNA knockdown of collagen-binding integrins on human umbilical vein endothelial cell migration and tube formation

Blood vessels in the body are lined with endothelial cells which have vital roles in numerous physiological and pathological processes. Collagens are major constituents of the extracellular matrix, and many adherent cells express several collagen-binding adhesion receptors. Here, we study the endothelium-collagen interactions mediated by the collagen-binding integrins, α1β1, α2β1, α10β1 and α11β1 expressed in human umbilical vein endothelial cells (HUVECs). Using qPCR, we found expression of the α10 transcript of the chondrocyte integrin, α10β1, along with the more abundant α2, and low-level expression of α1. The α11 transcript was not detected. Inhibition or siRNA knockdown of the α2-subunit resulted in impaired HUVEC adhesion, spreading and migration on collagen-coated surfaces, whereas inhibition or siRNA knockdown of α1 had no effect on these processes. In tube formation assays, inhibition of either α1 or α2 subunits impaired the network complexity, whereas siRNA knockdown of these integrins had no such effect. Knockdown of α10 had no effect on cell spreading, migration or tube formation in these conditions. Overall, our results indicate that the collagen-binding integrins, α1β1 and α2β1 play a central role in endothelial cell motility and self-organisation.

Extracellular vesicles as central regulators of blood vessel function in cancer

Blood vessels deliver oxygen and nutrients that sustain tumor growth and enable the dissemination of cancer cells to distant sites and the recruitment of intratumoral immune cells. In addition, the structural and functional abnormalities of the tumor vasculature foster the development of an aggressive tumor microenvironment and impair the efficacy of existing cancer therapies. Extracellular vesicles (EVs) have emerged as major players of tumor progression, and a growing body of evidence has demonstrated that EVs derived from cancer cells trigger multiple responses in endothelial cells that alter blood vessel function in tumors. EV-mediated signaling in endothelial cells can occur through the transfer of functional cargos such as miRNAs, lncRNAs, cirRNAs, and proteins. Moreover, membrane-bound proteins in EVs can elicit receptor-mediated signaling in endothelial cells. Together, these mechanisms reprogram endothelial cells and contribute to the sustained exacerbated angiogenic signaling typical of tumors, which, in turn, influences cancer progression. Targeting these angiogenesis-promoting EV-dependent mechanisms may offer additional strategies to normalize tumor vasculature. Here, we discuss the current knowledge pertaining to the contribution of cancer cell-derived EVs in mechanisms regulating blood vessel functions in tumors. Moreover, we discuss the translational opportunities in targeting the dysfunctional tumor vasculature using EVs and highlight the open questions in the field of EV biology that can be addressed using mass spectrometry-based proteomics analysis.

Role of the Endothelium in Neonatal Diseases

In both fetal and neonatal physiologic and pathologic processes in most organs, endothelial cells are known to play critical roles. Although the endothelium is one of the most ubiquitous cell type in the body, the tight adherence to the blood vessel wall has made it difficult to study their diverse function and structure. In this article, we have reviewed endothelial cell origins and explored their heterogeneity in terms of structure, function, developmental changes, and their role in inflammatory and infectious diseases. We have also attempted to evaluate the untapped therapeutic potentials of endothelial cells in neonatal disease. This article comprises various peer-reviewed studies, including ours, and an extensive database literature search from EMBASE, PubMed, and Scopus.

Integrin Regulated Autoimmune Disorders: Understanding the Role of Mechanical Force in Autoimmunity

The pathophysiology of autoimmune disorders is multifactorial, where immune cell migration, adhesion, and lymphocyte activation play crucial roles in its progression. These immune processes are majorly regulated by adhesion molecules at cell–extracellular matrix (ECM) and cell–cell junctions. Integrin, a transmembrane focal adhesion protein, plays an indispensable role in these immune cell mechanisms. Notably, integrin is regulated by mechanical force and exhibit bidirectional force transmission from both the ECM and cytosol, regulating the immune processes. Recently, integrin mechanosensitivity has been reported in different immune cell processes; however, the underlying mechanics of these integrin-mediated mechanical processes in autoimmunity still remains elusive. In this review, we have discussed how integrin-mediated mechanotransduction could be a linchpin factor in the causation and progression of autoimmune disorders. We have provided an insight into how tissue stiffness exhibits a positive correlation with the autoimmune diseases’ prevalence. This provides a plausible connection between mechanical load and autoimmunity. Overall, gaining insight into the role of mechanical force in diverse immune cell processes and their dysregulation during autoimmune disorders will open a new horizon to understand this physiological anomaly.

Microcomputed Tomography-Based Analysis of Neovascularization within Bioengineered Vascularized Tissues

In the field of tissue engineering, evaluating newly formed vascular networks is considered a fundamental step in deciphering the processes underlying tissue development. Several common modalities exist to study vessel network formation and function. However, a proper methodology that allows through three-dimensional visualization of neovessels in a reproducible manner is required. Here, we describe in-depth exploration, visualization, and analysis of vessels within newly formed tissues by utilizing a contrast agent perfusion protocol and high-resolution microcomputed tomography. Bioengineered constructs consisting of porous, biocompatible, and biodegradable scaffolds are loaded with cocultures of adipose-derived microvascular endothelial cells (HAMECs) and dental pulp stem cells (DPSCs) and implanted in a rat femoral bundle model. After 14 days of in vivo maturation, we performed the optimized perfusion protocol to allow host penetrating vascular visualization and assessment within neotissues. Following high-resolution microCT scanning of DPSC:HAMEC explants, we performed the volumetric and spatial analysis of neovasculature. Eventually, the process was repeated with a previously published coculture system for prevascularization based on adipose-derived mesenchymal stromal cells (MSCs) and HAMECs. Overall, our approach allows a comprehensive understanding of vessel organization during engraftment and development of neotissues.

Expression of mRNA vascular endothelial growth factor in hypospadias patients

Background

Hypospadias is a relatively common genital anomaly in humans, usually followed by inelastic dartos that causes penile chordee. Vascular endothelial growth factor (VEGF) is strongly linked to the viscoelasticity of tissues and their elastic phase. This study aimed to evaluate VEGF expressions in (1) fascia dartos between hypospadias and controls and (2) chordee severity.

Methods

This prospective cohort study involved 65 specimens from patients with hypospadias and ten specimens from controls. The samples were analyzed by quantitative real-time polymerase chain reaction (qPCR) for VEGF expression.

Results

The expressions of VEGF were not different between proximal and distal hypospadias patients and controls (fold change: distal − 0.25; fold change: proximal − 0.2; p = 0.664). The scaled expressions related to chordee severity were mild − 0.1; moderate 0.1; severe − 0.25 (p = 0.660).

Conclusions

VEGF expressions might not affect the severity of hypospadias and chordee, implying the pathogenesis is complex involving many growth factors. Further study with a larger sample size is necessary to clarify and confirm our findings.

Improved Immunotherapy Efficacy by Vascular Modulation

Several strategies have been developed to modulate the tumour vasculature for cancer therapy including anti-angiogenesis and vascular normalisation. Vasculature modulation results in changes to the tumour microenvironment including oxygenation and immune cell infiltration, therefore lending itself to combination with cancer therapy. The development of immunotherapies has led to significant improvements in cancer treatment. Particularly promising are immune checkpoint blockade and CAR T cell therapies, which use antibodies against negative regulators of T cell activation and T cells reprogrammed to better target tumour antigens, respectively. However, while immunotherapy is successful in some patients, including those with advanced or metastatic cancers, only a subset of patients respond. Therefore, better predictors of patient response and methods to overcome resistance warrant investigation. Poor, or periphery-limited, T cell infiltration in the tumour is associated with poor responses to immunotherapy. Given that (1) lymphocyte recruitment requires leucocyte-endothelial cell adhesion and (2) the vasculature controls tumour oxygenation and plays a pivotal role in T cell infiltration and activation, vessel targeting strategies including anti-angiogenesis and vascular normalisation in combination with immunotherapy are providing possible new strategies to enhance therapy. Here, we review the progress of vessel modulation in enhancing immunotherapy efficacy.

MiR-206 promotes extracellular matrix accumulation and relieves infantile hemangioma through targeted inhibition of DNMT3A

MiR-206 is abnormally expressed in infant hemangioma endothelial cells (HemECs), but the mechanism is not clear. We explored the intervention of miR-206 in HemECs in relation to extracellular matrix (ECM) metabolism. We selected 48 cases of infantile hemangioma (IH) from volunteer organizations. After the isolated and extracted HemECs were interfered with overexpressed or silenced miR-206, the effects of miR-206 on the proliferation, migration and invasion of HemECs were examined through basic cell function experiments. The expression differences of miR-206, DNA Methyltransferase 3A (DNMT3A) and ECM-related genes were analyzed as needed by qRT-PCR or Western blot. TargetScan and dual-luciferase experiments were applied to predict and confirm the binding relationship between miR-206 and DNMT3A. The correlation between miR-206 and DNMT3A was analyzed in IH tissues by Pearson correlation coefficient, and further confirmed in HemECs by conducting rescue experiments. A nude mouse model of xenograft tumor was constructed to verify the results of in vitro experiments. MiR-206, which was downregulated in proliferative hemangioma, suppressed the malignant development of HemECs by regulating ECM-related genes. As the target gene of miR-206, DNMT3A was high-expressed in IH tissues and was negatively correlated with miR-206. Overexpressed DNMT3A counteracted the inhibitory effect of miR-206 mimic on HemECs and its regulatory effect on ECM. The results of in vivo experiments were consistent with those from cell experiments. Thus, miR-206 could promote ECM accumulation through targeted inhibition of DNMT3A, further inhibiting the malignant development of HemECs and relieving IH.

Antimicrobial properties of olive oil phenolic compounds and their regenerative capacity towards fibroblast cells

Some micronutrients of vegetable origin are considered potentially useful as wound-healing agents because they can increase fibroblast proliferation and differentiation.

THE AIM OF THIS STUDY

was to evaluate the regenerative effects of selected olive oil phenolic compounds on cultured human fibroblasts and explore their antimicrobial properties.

MATERIAL AND METHODS

The CCD-1064Sk fibroblast line was treated for 24 h with 10^-6M luteolin, apigenin, ferulic, coumaric acid or caffeic acid, evaluating the effects on cell proliferation by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) spectrophotometric assay; the migratory capacity by the scratch assay and determining the expression of Fibroblast Growth Factor (FGF), Vascular Endothelial Growth Factor (VEGF), Transforming Growth Factor- β1 (TGFβ1), Platelet Derived Growth Factor (PDGF), and Collagen Type I (COL-I) genes by real-time polymerase chain reaction. The antimicrobial capacity of the polyphenols was evaluated by the disc diffusion method.

RESULTS

All compounds except for ferulic acid significantly stimulated the proliferative capacity of fibroblasts, increasing their migration and their expression of the aforementioned genes. With respect to their antimicrobial properties, treatment with the studied compounds inhibited the growth of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Proteus spp., and Candida Albicans.

CONCLUSIONS

The phenolic compounds in olive oil have a biostimulatory effect on the regeneration capacity, differentiation, and migration of fibroblasts and exert major antibacterial activity. According to the present findings, these compounds may have a strong therapeutic effect on wound recovery.

An Overview on the Conservative Management of Endometriosis from a Naturopathic Perspective: Phytochemicals and Medicinal Plants

Background: Endometriosis is a chronic and debilitating disease, which affects millions of young women worldwide. Although medicine has incontestably evolved in the last years, there is no common ground regarding the early and accurate diagnosis of this condition, its pathogenic mechanisms, and curative treatment. Even though the spontaneous resolution of endometriosis is sometimes possible, recent reports suggested that it can be a progressive condition. It can associate chronic pelvic pain, vaginal bleeding, infertility, or malignant degenerescence. Conventional treatments could produce many side effects, and despite treatment, the symptoms may reappear. In recent years, experimental evidence suggested that plant-based medicine could exert beneficial effects on endometriosis and endometriosis-related symptoms. This study aims to highlight the pharmaceutical activity of phytochemicals and medicinal plants against endometriosis and to provide a source of information regarding the alternative treatment of this condition. Methods: For this review, we performed a research using PubMed, GoogleScholar, and CrossRef databases. We selected the articles published between January 2000 and July 2020, written in English. Results: We found 17 medicinal plants and 13 phytochemicals, which have demonstrated their beneficial effects against endometriosis. Several of their biological activities consist of antiangiogenic, anti-inflammatory effects, and oxidative-stress reduction. Conclusion: Medicinal herbs and their bioactive compounds exhibit antiangiogenic, antioxidant, sedative and pain-alleviating properties and the effects recorded until now encourage their use for the conservative management of endometriosis.

Understanding the role of integrins in breast cancer invasion, metastasis, angiogenesis, and drug resistance

Integrins are cell adhesion receptors, which are typically transmembrane glycoproteins that connect to the extracellular matrix (ECM). The function of integrins regulated by biochemical events within the cells. Understanding the mechanisms of cell growth by integrins is important in elucidating their effects on tumor progression. One of the major events in integrin signaling is integrin binding to extracellular ligands. Another event is distant signaling that gathers chemical signals from outside of the cell and transmit the signals upon cell adhesion to the inside of the cell. In normal breast tissue, integrins function as checkpoints to monitor effects on cell proliferation, while in cancer tissue these functions altered. The combination of tumor microenvironment and its associated components determines the cell fate. Hypoxia can increase the expression of several integrins. The exosomal integrins promote the growth of metastatic cells. Expression of certain integrins is associated with increased metastasis and decreased prognosis in cancers. In addition, integrin-binding proteins promote invasion and metastasis in breast cancer. Targeting specific integrins and integrin-binding proteins may provide new therapeutic approaches for breast cancer therapies. This review will examine the current knowledge of integrins' role in breast cancer.

Review of Integrin-Targeting Biomaterials in Tissue Engineering

The ability to direct cell behavior has been central to the success of numerous therapeutics to regenerate tissue or facilitate device integration. Biomaterial scientists are challenged to understand and modulate the interactions of biomaterials with biological systems in order to achieve effective tissue repair. One key area of research investigates the use of extracellular matrix-derived ligands to target specific integrin interactions and induce cellular responses, such as increased cell migration, proliferation, and differentiation of mesenchymal stem cells. These integrin-targeting proteins and peptides have been implemented in a variety of different polymeric scaffolds and devices to enhance tissue regeneration and integration. This review first presents an overview of integrin-mediated cellular processes that have been identified in angiogenesis, wound healing, and bone regeneration. Then, research utilizing biomaterials are highlighted with integrin-targeting motifs as a means to direct these cellular processes to enhance tissue regeneration. In addition to providing improved materials for tissue repair and device integration, these innovative biomaterials provide new tools to probe the complex processes of tissue remodeling in order to enhance the rational design of biomaterial scaffolds and guide tissue regeneration strategies.

Current Understanding of the Emerging Role of Prolidase in Cellular Metabolism

Prolidase [EC 3.4.13.9], known as PEPD, cleaves di- and tripeptides containing carboxyl-terminal proline or hydroxyproline. For decades, prolidase has been thoroughly investigated, and several mechanisms regulating its activity are known, including the activation of the β₁-integrin receptor, insulin-like growth factor 1 receptor (IGF-1) receptor, and transforming growth factor (TGF)-β₁ receptor. This process may result in increased availability of proline in the mitochondrial proline cycle, thus making proline serve as a substrate for the resynthesis of collagen, an intracellular signaling molecule. However, as a ligand, PEPD can bind directly to the epidermal growth factor receptor (EGFR, epidermal growth factor receptor 2 (HER2)) and regulate cellular metabolism. Recent reports have indicated that PEPD protects p53 from uncontrolled p53 subcellular activation and its translocation between cellular compartments. PEPD also participates in the maturation of the interferon α/β receptor by regulating its expression. In addition to the biological effects, prolidase demonstrates clinical significance reflected in the disease known as prolidase deficiency. It is also known that prolidase activity is affected in collagen metabolism disorders, metabolic, and oncological conditions. In this article, we review the latest knowledge about prolidase and highlight its biological function, and thus provide an in-depth understanding of prolidase as a dipeptidase and protein regulating the function of key biomolecules in cellular metabolism.

Collagen, stiffness, and adhesion: the evolutionary basis of vertebrate mechanobiology

The emergence of collagen I in vertebrates resulted in a dramatic increase in the stiffness of the extracellular environment, supporting long-range force propagation and the development of low-compliant tissues necessary for the development of vertebrate traits including pressurized circulation and renal filtration. Vertebrates have also evolved integrins that can bind to collagens, resulting in the generation of higher tension and more efficient force transmission in the extracellular matrix. The stiffer environment provides an opportunity for the vertebrates to create new structures such as the stress fibers, new cell types such as endothelial cells, new developmental processes such as neural crest delamination, and new tissue organizations such as the blood-brain barrier. Molecular players found only in vertebrates allow the modification of conserved mechanisms as well as the design of novel strategies that can better serve the physiological needs of the vertebrates. These innovations collectively contribute to novel morphogenetic behaviors and unprecedented increases in the complexities of tissue mechanics and functions.

Hepatic Stellate Cell-Macrophage Crosstalk in Liver Fibrosis and Carcinogenesis

Chronic liver injury due to viral hepatitis, alcohol abuse, and metabolic disorders is a worldwide health concern. Insufficient treatment of chronic liver injury leads to fibrosis, causing liver dysfunction and carcinogenesis. Most cases of hepatocellular carcinoma (HCC) develop in the fibrotic liver. Pathological features of liver fibrosis include extracellular matrix (ECM) accumulation, mesenchymal cell activation, immune deregulation, and angiogenesis, all of which contribute to the precancerous environment, supporting tumor development. Among liver cells, hepatic stellate cells (HSCs) and macrophages play critical roles in fibrosis and HCC. These two cell types interplay and remodel the ECM and immune microenvironment in the fibrotic liver. Once HCC develops, HCC-derived factors influence HSCs and macrophages to switch to protumorigenic cell populations, cancer-associated fibroblasts and tumor-associated macrophages, respectively. This review aims to summarize currently available data on the roles of HSCs and macrophages in liver fibrosis and HCC, with a focus on their interaction.

How Fat Grafting Works

Fat grafting has been shown to improve diseased soft issue. Although the mechanism behind fat grafting’s regenerative properties is currently debated, published studies agree that there is an associated vasculogenic effect. A systematic literature review was conducted to elucidate the biochemical pathways responsible for establishing neo-vasculature to grafted fat.

Alternagin-C (ALT-C), a disintegrin-like protein, attenuates alpha2beta1 integrin and VEGF receptor 2 signaling resulting in angiogenesis inhibition

Angiogenesis, a crucial process in tumor progression, is mainly regulated by vascular endothelial growth factor (VEGF) and its receptor, VEGFR2. Studies have shown the interaction between α₂β₁ integrin, a collagen receptor, and VEGFR2 in VEGF-driven angiogenesis in vitro and in vivo. Alternagin-C (ALT-C), an ECD-disintegrin-like protein from Bothrops alternatus snake venom, has high affinity for α₂β₁ integrin and shows antiangiogenic activity in concentrations higher than 100 nM. Despite previous results, its mechanism of action on angiogenic signaling pathways has not been addressed. Here we evaluate the antiangiogenic activity of ALT-C in human umbilical vein endothelial cells (HUVECs) associated or not with VEGF, as well as its interference in the α₂β₁/VEGFR2 crosstalk. ALT-C (1000 nM) affected actin cytoskeleton, decreased the number of cell filopodia, and strongly inhibited HUVEC tube formation, adhesion to type I collagen and cell migration. Down-regulation of α₂β₁/VEGFR2 crosstalk by ALT-C decreased the protein content and phosphorylation of VEGFR2 and β₁ integrin subunit, inhibited ERK 1/2 and PI3K signaling and regulated FAK/Src and paxillin pathways. Furthermore, ALT-C increased the content of the autophagic markers LC3B and Beclin-1 in the presence of VEGF, which is associated with decreased angiogenesis. In conclusion, we suggest that ALT-C, after binding to α₂β₁ integrin, inhibits VEGF/VEGFR2 signaling, which results in impaired angiogenesis. These results demonstrate that ALT-C may be a potential candidate for the development of antiangiogenic therapies for tumor and metastasis treatment and help to understand the complexity and fundamental role of integrin inhibition in the tumor microenvironment.

OPN binds alpha V integrin to promote endothelial progenitor cell incorporation into vasculature

Angiogenesis is fundamental to the expansion of the placental vasculature during pregnancy. Integrins are associated with vascular formation; and osteopontin is a candidate ligand for integrins to promote angiogenesis. Endothelial progenitor cells (EPCs) are released from bone marrow into the blood and incorporate into newly vascularized tissue where they differentiate into mature endothelium. Results of studies in women suggest that EPCs may play an important role in maintaining placental vascular integrity during pregnancy, although little is known about how EPCs are recruited to these tissues. Our goal was to determine the αv integrin mediated effects of osteopontin on EPC adhesion and incorporation into angiogenic vascular networks. EPCs were isolated from 6 h old piglets. RT-PCR revealed that EPCs initially had a monocyte-like phenotype in culture that became more endothelial-like with cell passage. Immunofluorescence microscopy confirmed that the EPCs express platelet endothelial cell adhesion molecule, vascular endothelial cadherin, and von Willebrand factor. When EPCs were cultured on OPN-coated slides, the αv integrin subunit was observed in focal adhesions at the basal surface of EPCs. Silencing of αv integrin reduced EPC binding to OPN and focal adhesion assembly. In vitro siRNA knockdown in EPCs,demonstrated that OPN stimulates EPC incorporation into human umbilical vein endothelial cell (HUVEC) networks via αv-containing integrins. Finally, in situ hybridization and immunohistochemistry localized osteopontin near placental blood vessels. In summary, OPN binds the αv integrin subunit on EPCs to support EPC adhesion and increase EPC incorporation into angiogenic vascular networks.

Human peroxidasin 1 promotes angiogenesis through ERK1/2, Akt, and FAK pathways

Aims

The term angiogenesis refers to sprouting of new blood vessels from pre-existing ones. The angiogenic process involves cell migration and tubulogenesis requiring interaction between endothelial cells and the extracellular matrix. Human peroxidasin 1 (hsPxd01) is a multidomain heme peroxidase found embedded in the basement membranes. As it promotes the stabilization of extracellular matrix, we investigated its possible role in angiogenesis both in vitro and in vivo.

Methods and results

We analysed the effects of peroxidasin 1 gene silencing and supplementation by recombinant hsPxd01 in TeloHAEC endothelial cells on cell migration, tubulogenesis in matrigel, and intracellular signal transduction as assessed by kinase phosphorylation and expression of pro-angiogenic genes as measured by qRT-PCR. We further evaluated the angiogenic potential of recombinant peroxidasin in a chicken chorioallantoic membrane model. RNA silencing of endogenous hsPxd01 significantly reduced tube formation and cell migration, whereas supplementation by the recombinant peroxidase promoted tube formation in vitro and stimulated vascularization in vivo through its catalytic activity. Moreover, recombinant hsPxd01 promoted phosphorylation of Extracellular signal-Regulated Kinases (ERK1/2), Protein kinase B (Akt), and Focal Adhesion Kinase (FAK), and induced the expression of pro-angiogenic downstream genes: Platelet Derived Growth Factor Subunit B (PDGFB), endothelial-derived Heparin Binding EGF-like growth factor (HB-EGF), CXCL-1, Hairy-Related Transcription Factor 1 (HEY-1), DNA-binding protein inhibitor (ID-2), Snail Family Zinc Finger 1 (SNAI-1), as well as endogenous hsPxd01. However, peroxidasin silencing significantly reduced Akt and FAK phosphorylation but induced ERK1/2 activation after supplementation by recombinant hsPxd01. While hsPxd01 silencing significantly reduced expression of HEY-1, ID-2, and PDGFB, it did not affect expression of SNAI-1, HB-EGF, and CXCL-1 after supplementation by recombinant hsPxd01.

Conclusion

Our findings suggest a role of enzymatically active peroxidasin 1 as a pro-angiogenic peroxidase and a modulator of ERK1/2, Akt and FAK signalling.

Isolation of an Anti-Tumour Disintegrin: Dabmaurin-1, a Peptide Lebein-1-Like, from Daboia mauritanica Venom

In the soft treatment of cancer tumours, consequent downregulation of the malignant tissue angiogenesis constitutes an efficient way to stifle tumour development and metastasis spreading. As angiogenesis requires integrin–promoting endothelial cell adhesion, migration, and vessel tube formation, integrins represent potential targets of new therapeutic anti–angiogenic agents. Our work is a contribution to the research of such therapeutic disintegrins in animal venoms. We report isolation of one peptide, named Dabmaurin–1, from the hemotoxic venom of snake Daboia mauritanica, and we evaluate its potential anti–tumour activity through in vitro inhibition of the human vascular endothelial cell HMECs functions involved in tumour angiogenesis. Dabmaurin–1 altered, in a dose–dependent manner, without any significant cytotoxicity, HMEC proliferation, adhesion, and their mesenchymal migration onto various extracellular matrix proteins, as well as formation of capillary–tube mimics on Matrigel^TM. Via experiments involving HMEC or specific cancers cells integrins, we demonstrated that the above Dabmaurin–1 effects are possibly due to some anti–integrin properties. Dabmaurin–1 was demonstrated to recognize a broad panel of prooncogenic integrins (αvβ6, αvβ3 or αvβ5) and/or particularly involved in control of angiogenesis (α5β1, α6β4, αvβ3 or αvβ5). Furthermore, mass spectrometry and partial N–terminal sequencing of this peptide revealed, it is close to Lebein–1, a known anti–β1 disintegrin from Macrovipera lebetina venom. Therefore, our results show that if Dabmaurin–1 exhibits in vitro apparent anti–angiogenic effects at concentrations lower than 30 nM, it is likely because it acts as an anti–tumour disintegrin.

Crucial Role for Endothelial Cell α2β1 Integrin Receptor Clustering in Collagen-Induced Angiogenesis

Angiogenesis is a crucial mechanism of vascular growth and regeneration that requires biosynthesis and cross-linking of collagens in vivo and is induced by collagen in vitro. Here, we use an in vitro model in which apical Type I collagen gels rapidly induce angiogenesis in endothelial monolayers. We extend previous studies demonstrating the importance of the endothelial α2β1 integrin, a key collagen receptor, in angiogenesis by investigating the roles of receptor clustering and conformational activation. Immunocytochemical localization of α2β1 integrins in endothelial monolayers showed a concentration of integrins along cell-cell borders. After inducing angiogenesis with collagen, the receptors redistributed to apical cell surfaces, aligning with collagen fibers, which were also redistributed during angiogenesis. Levels of conformationally activated α2β1 integrins were unchanged during angiogenesis and undetected on endothelial cells binding collagen in suspension. We mimicked the polyvalency of collagen fibrils using antibody-coated polystyrene beads to cluster endothelial cell surface α2β1 integrins, which induced rapid angiogenesis in the absence of collagen gels. Clustering of αvβ3 integrins and PECAM-1 but not of α1 integrins also induced angiogenesis. Soluble antibodies alone had no effect. Thus, the angiogenic property of collagen may reside in its ability to ligate and cluster cell surface receptors such as α2β1 integrins. Furthermore, synthetic substrates that promote the clustering of select endothelial cell surface receptors mimic the angiogenic properties of Type I collagen and may have applications in promoting vascularization of engineered tissues. Anat Rec, 2019. © 2019 American Association for Anatomy.

Mechanical Forces in Tumor Angiogenesis

A defining hallmark of cancer and cancer development is upregulated angiogenesis. The vasculature formed in tumors is structurally abnormal, not organized in the conventional hierarchical arrangement, and more permeable than normal vasculature. These features contribute to leaky, tortuous, and dilated blood vessels, which act to create heterogeneous blood flow, compression of vessels, and elevated interstitial fluid pressure. As such, abnormalities in the tumor vasculature not only affect the delivery of nutrients and oxygen to the tumor, but also contribute to creating an abnormal tumor microenvironment that further promotes tumorigenesis. The role of chemical signaling events in mediating tumor angiogenesis has been well researched; however, the relative contribution of physical cues and mechanical regulation of tumor angiogenesis is less understood. Growing research indicates that the physical microenvironment plays a significant role in tumor progression and promoting abnormal tumor vasculature. Here, we review how mechanical cues found in the tumor microenvironment promote aberrant tumor angiogenesis. Specifically, we discuss the influence of matrix stiffness and mechanical stresses in tumor tissue on tumor vasculature, as well as the mechanosensory pathways utilized by endothelial cells to respond to the physical cues found in the tumor microenvironment. We also discuss the impact of the resulting aberrant tumor vasculature on tumor progression and therapeutic treatment.

TargetAntiAngio: A Sequence-Based Tool for the Prediction and Analysis of Anti-Angiogenic Peptides

Cancer remains one of the major causes of death worldwide. Angiogenesis is crucial for the pathogenesis of various human diseases, especially solid tumors. The discovery of anti-angiogenic peptides is a promising therapeutic route for cancer treatment. Thus, reliably identifying anti-angiogenic peptides is extremely important for understanding their biophysical and biochemical properties that serve as the basis for the discovery of new anti-cancer drugs. This study aims to develop an efficient and interpretable computational model called TargetAntiAngio for predicting and characterizing anti-angiogenic peptides. TargetAntiAngio was developed using the random forest classifier in conjunction with various classes of peptide features. It was observed via an independent validation test that TargetAntiAngio can identify anti-angiogenic peptides with an average accuracy of 77.50% on an objective benchmark dataset. Comparisons demonstrated that TargetAntiAngio is superior to other existing methods. In addition, results revealed the following important characteristics of anti-angiogenic peptides: (i) disulfide bond forming Cys residues play an important role for inhibiting blood vessel proliferation; (ii) Cys located at the C-terminal domain can decrease endothelial formatting activity and suppress tumor growth; and (iii) Cyclic disulfide-rich peptides contribute to the inhibition of angiogenesis and cell migration, selectivity and stability. Finally, for the convenience of experimental scientists, the TargetAntiAngio web server was established and made freely available online.

Evaluation of dehydrated human umbilical cord biological properties for wound care and soft tissue healing

Chronic wounds are a significant health care problem with serious implications for quality of life because they do not properly heal and often require therapeutic intervention. Amniotic membrane allografts have been successfully used as a biologic therapy to promote soft tissue healing; however, the umbilical cord, another placental-derived tissue, has also recently garnered interest because of its unique composition but similar placental tissue origin. The aim of this study was to characterize PURION® PLUS Processed dehydrated human umbilical cord (dHUC) and evaluate the biological properties of this tissue that contribute to healing. This was performed through the characterization of the tissue composition, evaluation of in vitro cellular response to dHUC treatment, and in vivo bioresorption and tissue response in a rat model. It was observed that dHUC contains collagen I, hyaluronic acid, laminin, and fibronectin. Additionally, 461 proteins that consist of growth factors and cytokines, inflammatory modulators, chemokines, proteases and inhibitors, adhesion molecules, signaling receptors, membrane-bound proteins, and other soluble regulators were detected. Cell-based assays demonstrated an increase in adipose-derived stem cell and mesenchymal stem cell proliferation, fibroblast migration and endothelial progenitor cell vessel formation in a dose-dependent manner after dHUC treatment. Lastly, rat subcutaneous implantation demonstrated biocompatibility since dHUC allografts were resorbed without fibrous encapsulation. These findings establish that dHUC possesses biological properties that stimulate cellular responses important for soft tissue healing. © 2018 The Authors. Journal Of Biomedical Materials Research Part B: Applied Biomaterials Published By Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1035-1046, 2019.

Bush-like integrin filament networks associated with hyaloid vasculature in murine neonate eyes

The vitreous of perinatal mice temporarily develops a unique vascular system, called the vasa hyaloidea propria (VHP). Observations showed the vessels possessed an extracellular matrix including the basement membrane in their entire length. Immunostaining of whole mount preparations of VHP with integrin β₁ antibody displayed a bush-like network consisting of long and straight fibers which were associated with the VHP but extended apart from the blood vessels. Electron microscopically, each fiber was composed of a bundle of thin filaments different from collagen fibrils. Macrophages associated with the VHP appeared to be arrested by the integrin bushes. The integrin bushes fragmented and disappeared by postnatal day 10, just before the regression of the VHP. Macrophages were involved in the digestion and clearance of integrin bushes. The vitreous integrin bushes appear to provide a scaffold for architectural maintenance of the hyaloid vessels and macrophages.

Mast Cell Protease 7 Promotes Angiogenesis by Degradation of Integrin Subunits

Previous studies from our laboratory have shown that during angiogenesis in vitro, rmMCP-7 (recombinant mouse mast cell protease-7) stimulates endothelial cell spreading and induces their penetration into the matrix. The ability of rmMCP-7 to induce angiogenesis in vivo was assessed in the present study using a directed in vivo angiogenesis assay (DIVAA™). Vessel invasion of the angioreactor was observed in the presence of rmMCP-7 but was not seen in the control. Since integrins are involved in endothelial cell migration, the relationship between rmMCP-7 and integrins during angiogenesis was investigated. Incubation with rmMCP-7 resulted in a reduction in the levels of integrin subunits αv and β1 on SVEC4-10 endothelial cells during angiogenesis in vitro. Furthermore, the degradation of integrin subunits occurs both through the direct action of rmMCP-7 and indirectly via the ubiquitin/proteasome system. Even in the presence of a proteasome inhibitor, incubation of endothelial cells with rmMCP-7 induced cell migration and tube formation as well as the beginning of loop formation. These data indicate that the direct degradation of the integrin subunits by rmMCP-7 is sufficient to initiate angiogenesis. The results demonstrate, for the first time, that mMCP-7 acts in angiogenesis through integrin degradation.

Biomarkers of Endothelial Dysfunction in Women With Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of childbearing age. The criteria required for the diagnosis identify various phenotypes, with different reproductive, metabolic, and cardiovascular (CV) risk characteristics. Emerging evidence links adipocyte-secreted hormones as candidates in the pathogenesis of endothelial dysfunction in PCOS, independently of additional risk factors. The aim of this review was to collect, analyze, and qualitatively resynthesize evidence on biomarkers of endothelial dysfunction (visfatin, vascular endothelial growth factor [VEGF], matrix metalloproteinase 9 [MMP-9]) in women with PCOS. Women with PCOS exhibit (a) increased plasma visfatin concentrations compared with controls with a similar body mass index; (b) increased VEGF production along with chronic, mild inflammation; and (c) increased MMP-9 concentrations, which might be related to either excessive CV risk or abnormalities of ovarian extracellular matrix remodeling, multiple cyst formation, follicular atresia, and chronic anovulation. As PCOS has been associated with CV risk, early identification of endothelial dysfunction is clinically relevant.

SNX9 determines the surface levels of integrin β1 in vascular endothelial cells: Implication in poor prognosis of human colorectal cancers overexpressing SNX9

Angiogenesis, the formation of new blood vessels, is involved in a variety of diseases including the tumor growth. In response to various angiogenic stimulations, a number of proteins on the surface of vascular endothelial cells are activated to coordinate cell proliferation, migration, and spreading processes to form new blood vessels. Plasma membrane localization of these angiogenic proteins, which include vascular endothelial growth factor receptors and integrins, are warranted by intracellular membrane trafficking. Here, by using a siRNA library, we screened for the sorting nexin family that regulates intracellular trafficking and identified sorting nexin 9 (SNX9) as a novel angiogenic factor in human umbilical vein endothelial cells (HUVECs). SNX9 was essential for cell spreading on the Matrigel, and tube formation that mimics in vivo angiogenesis in HUVECs. SNX9 depletion significantly delayed the recycling of integrin β1, an essential adhesion molecule for angiogenesis, and reduced the surface levels of integrin β1 in HUVECs. Clinically, we showed that SNX9 protein was highly expressed in tumor endothelial cells of human colorectal cancer tissues. High-level expression of SNX9 messenger RNA significantly correlated with poor prognosis of the patients with colorectal cancer. These results suggest that SNX9 is an angiogenic factor and provide a novel target for the development of new antiangiogenic drugs.

The soluble nectin-4 ecto-domain promotes breast cancer induced angiogenesis via endothelial Integrin-β4

Cancer stem cells secrete diffusible factors into the microenvironment that bind to specific endothelial cell receptors and initiate an angiogenesis cascade. Tumor-induced angiogenesis is an important parameter of tumorigenesis and is critical for tumor growth and metastasis. A pvrl-4 encoded gene, NECTIN-4, has potential roles in cancer cell growth and aggressiveness, and it is only expressed in cancer cells. There is evidence that nectin-4 plays a role in tumorigenesis, but the function of nectin-4 in tumor angiogenesis has lacked thorough evidence of mechanism. Using highly metastatic breast cancer cells and human umbilical vein endothelial cells (HUVECs), we have developed an excellent angiogenesis model and systematically studied the contribution of nectin-4 to angiogenesis. We also provide in-depth in ovo, in vivo and in vivo evidence that nectin-4 causes angiogenesis. Following hypoxia, metastatic breast cancer stem cells (mBCSCs) driven ADAM-17 expression causes the shedding of the ecto-domain of nectin-4 into the microenvironment, which physically interacts with integrin-β4 specifically on endothelial cells. This interaction promotes angiogenesis via the Src, PI3K, AKT, iNOS pathway and not by Phospho-Erk or NF-κβ pathways. In vitro, in ovo and in vivo induction and abrogation of an angiogenesis cascade in the presence and absence of the nectin-4 ecto-domain, respectively, confirms its role in angiogenesis. Thus, disrupting the interaction between nectin-4 ecto-domain and integrin-β4 may provide a means of targeting mBCSC-induced angiogenesis.

Antioxidant and anticancer activities of Trigonella foenum-graecum, Cassia acutifolia and Rhazya stricta

BACKGROUND

Here, we determined in vitro antioxidant activity, total phenols and flavonoids and evaluated antiproliferative activity of three medicinal plant extracts: Trigonella foenum-graecum (Fenugreek), Cassia acutifolia (Senna) and Rhazya stricta (Harmal).

METHODS

The leaves of the three medicinal plants were extracted with 70% ethanol. Antioxidant activities of the extracts were determined by using DPPH (1,1-diphenyl-2-picrylhydrazyl) assay. Total flavonoid and phenolic contents were determined using colorimetric assays. MTT assay was used to estimate the antiproliferative activities of the extracts against human hepatoma (HepG2) cancer cell line. In addition, the effects of R. stricta extract on cell cycle, colony formation, and wound healing of HepG2 cells and tube formation of HUVEC cells were assessed.

RESULTS

Percentage inhibition of DPPH scavenging activity were dose-dependent and ranged between (89.9% ± 0.51) and (28.6% ± 2.07). Phenolic contents ranged between (11.5 ± 0.013) and (9.7 ± 0.008) mg GAE/g while flavonoid content ranged between (20.8 ± 0.40) and (0.12 ± 0.0.01) mg QE/g. Antiproliferative results of the extracts were found to be consistent with their antioxidant activity. Among the extracts evaluated, that of R. stricta showed the best antioxidant, antiproliferative and antimetastatic activities at low concentration. It also inhibited the colony-formation capacity of HepG2 cells and exhibited antiangiogenic activity. Cell cycle analysis showed significant arrest of cells at G2/M phase 12 and 48 h after treatment and significant arrest at G1/S phase after 24 h of treatment. Consistent data were observed in western blot analysis of protein levels of Cdc2 and its cyclin partners.

CONCLUSIONS

These findings introduce R. stricta as a potentially useful anti-metastatic agent and a novel potential anti-tumour agent for hepatocellular carcinoma (HCC) treatment.

Molecular profiling of reticular gigantocellularis neurons indicates that eNOS modulates environmentally dependent levels of arousal

Neurons of the medullary reticular nucleus gigantocellularis (NGC) and their targets have recently been a focus of research on mechanisms supporting generalized CNS arousal (GA) required for proper cognitive functions. Using the retro-TRAP method, we characterized transcripts enriched in NGC neurons which have projections to the thalamus. The unique expression and activation of the endothelial nitric oxide (eNOS) signaling pathway in these cells and their intimate connections with blood vessels indicate that these neurons exert direct neurovascular coupling. Production of nitric oxide (NO) within eNOS-positive NGC neurons increases after environmental perturbations, indicating a role for eNOS/NO in modulating environmentally appropriate levels of GA. Inhibition of NO production causes dysregulated behavioral arousal after exposure to environmental perturbation. Further, our findings suggest interpretations for associations between psychiatric disorders and mutations in the eNOS locus.

Sulfated zwitterionic poly(sulfobetaine methacrylate) hydrogels promote complete skin regeneration

Skin wound healing is a still long-history challenging problem and impeded by the foreign-body reaction including severe inflammation response, poor neovascularization, incomplete re-epithelialization and defective ECM remodeling. Development of biocompatible polymers, in combination with specific drugs or growth factors, has been considered as a promising strategy to treat skin wounds. Significant research efforts have been made to develop poly(ethylene glycol) PEG-based polymers for wound healing, however less efforts has been paid to zwitterionic materials, some of which have demonstrated their super low-fouling property in vitro and anti-inflammatory property in vivo. Here, we synthesized ultra-low-fouling zwitterionic sulfated poly(sulfobetaine methacrylate) (polySBMA) hydrogels and applied them to full-thickness cutaneous wounds in mice. The healing effects of SBMA hydrogels on the wound closure, re-epithelialization ratio, ECM remodeling, angiogenesis, and macrophage responses during wound healing processes were histologically evaluated by in vivo experiments. Collective results indicate that SBMA hydrogels promote full-thickness excisional acute wound regeneration in mice by enhancing angiogenesis, decreasing inflammation response, and modulating macrophage polarization. Consistently, the incorporation of SBMA into PEG hydrogels also improved the overall wound healing efficiency as compared to pure PEG hydrogels. This work demonstrates zwitterionic SBMA hydrogels as promising wound dressings for treating full-thickness excisional skin wounds.

STATEMENT OF SIGNIFICANCE

Development of highly effective wound regeneration system is practically important for biomedical applications. Here, we synthesized ultra-low-fouling zwitterionic sulfated poly(sulfobetaine methacrylate) (polySBMA) hydrogels and applied it to full-thickness cutaneous wounds in mice, in comparison with PEG hydrogels as a control. We are the first to examine and reveal the difference between zwitterionic SBMA hydrogels and PEG hydrogels using a full-thickness excisional mice model. Overall, a series of in vivo systematic tests demonstrated that zwitterionic SBMA hydrogels exhibited superior wound healing property in almost all aspects as compared to PEG hydrogels.

Molecular Regulation of Sprouting Angiogenesis

The term angiogenesis arose in the 18th century. Several studies over the next 100 years laid the groundwork for initial studies performed by the Folkman laboratory, which were at first met with some opposition. Once overcome, the angiogenesis field has flourished due to studies on tumor angiogenesis and various developmental models that can be genetically manipulated, including mice and zebrafish. In addition, new discoveries have been aided by the ability to isolate primary endothelial cells, which has allowed dissection of various steps within angiogenesis. This review will summarize the molecular events that control angiogenesis downstream of biochemical factors such as growth factors, cytokines, chemokines, hypoxia-inducible factors (HIFs), and lipids. These and other stimuli have been linked to regulation of junctional molecules and cell surface receptors. In addition, the contribution of cytoskeletal elements and regulatory proteins has revealed an intricate role for mobilization of actin, microtubules, and intermediate filaments in response to cues that activate the endothelium. Activating stimuli also affect various focal adhesion proteins, scaffold proteins, intracellular kinases, and second messengers. Finally, metalloproteinases, which facilitate matrix degradation and the formation of new blood vessels, are discussed, along with our knowledge of crosstalk between the various subclasses of these molecules throughout the text. Compr Physiol 8:153-235, 2018.

Cullin-3 and its adaptor protein ANKFY1 determine the surface level of integrin β1 in endothelial cells

Angiogenesis, the formation of new blood vessels from the pre-existing vasculature, is related to numerous pathophysiological events. We previously reported that a RING ubiquitin ligase complex scaffold protein, cullin-3 (CUL3), and one of its adaptor proteins, BAZF, regulated angiogenesis in the mouse retina by suppressing Notch signaling. However, the degree of inhibition of angiogenesis was made greater by CUL3 depletion than by BAZF depletion, suggesting other roles of CUL3 in angiogenesis besides the regulation of Notch signaling. In the present study, we found that CUL3 was critical for the cell surface level of integrin β1, an essential cell adhesion molecule for angiogenesis in HUVECs. By siRNA screening of 175 BTBPs, a family of adaptor proteins for CUL3, we found that ANKFY1/Rabankyrin-5, an early endosomal BTBP, was also critical for localization of surface integrin β1 and angiogenesis. CUL3 interacted with ANKFY1 and was required for the early endosomal localization of ANKFY1. These data suggest that CUL3/ANKFY1 regulates endosomal membrane traffic of integrin β1. Our results highlight the multiple roles of CUL3 in angiogenesis, which are mediated through distinct CUL3-adaptor proteins.

Integrins in Vascular Development and Pathology

During vascular development, endothelial cells (ECs) and neighboring stromal cells interact and communicate through autocrine and paracrine signaling mechanisms involving extracellular matrix (ECM) proteins and their cell surface integrin adhesion receptors. Integrin-mediated adhesion and signaling pathways are crucial for normal vascular development and physiology, and alterations in integrin expression and/or function drive several vascular-related pathologies including thrombosis, autoimmune disorders, and cancer. The purpose of this chapter is to discuss integrin adhesion and signaling pathways important for EC growth, survival, and migration. Integrin-mediated paracrine links between ECs and surrounding stromal cells in the organ microenvironment will also be discussed. Lastly, we will review roles for integrins in vascular pathologies and discuss possible targets for therapeutic intervention.

Enhancement of abdominal wall defect repair using allogenic platelet-rich plasma with commercial polyester/cotton fabric (Damour) in a canine model

Platelet-rich plasma (PRP) has an important role in musculoskeletal surgery; however, it has been underutilized for accelerating the healing of abdominal wall defects in veterinary practice. Therefore, the aim of this study was to evaluate the use of commercial polyester/cotton fabric (Damour) as a new composite mesh for the repair of experimentally induced abdominal wall defects in canine models, and to investigate the possible role of PRP for improving such repair and reducing allied complications. For this purpose, abdominal wall defects were created in 24 healthy mongrel dogs and then repaired with mesh alone (control group) or mesh and allogenic PRP (PRP group). Dogs were euthanized after 2 or 4 months for gross examination of implantation site, detection of adhesion score and hernia recurrence. Moreover, tissue samples were collected for histological and gene expression analyses for neovascularization, collagen formation and tissue incorporation. Hernia recurrence was not recorded in PRP-treated dogs that also displayed significantly more neovascularization and less severe adhesion to the underlings (1.08 ± 0.51) in comparison to control group (2.08 ± 0.99). Histological and molecular evaluation confirmed the gross findings that collagen deposition, new vessel formation, and overexpression of angiogenic and myofibroplastic genes (COL1α1, COL3α1, VEGF and TGFβ1) were observed more frequently in the PRP group, at both time points. In conclusion, we found that addition of allogenic PRP to Damour mesh enhanced neovessel formation, and increased tissue deposition and incorporation, with subsequent reduction of peritoneal adhesion and recurrence rate.