• acute pulmonary embolism
• chronic thromboembolic pulmonary hypertension
• fibrotic thrombus formation
• gene expression
• pulmonary hypertension
• pulmonary vascular remodeling

• Humans
• Chronic Disease/epidemiology
• Hypertension, Pulmonary/epidemiology
• Hypertension, Pulmonary/etiology
• Hypertension, Pulmonary/physiopathology
• Pulmonary Embolism/complications
• Pulmonary Embolism/epidemiology
• Pulmonary Embolism/physiopathology
• Risk Factors

• Neuroscience
• Stem cells research

• Osler Weber Rendu Syndrome
• drug-related side effects and adverse reactions
• epistaxis
• microtubule disruption
• pharmacology
• propranolol
• receptor ErbB-2
• telangiectasis

• Airway remodelling
• Asthma
• Berberine
• COPD
• Liquid crystalline nanoparticles
• Lung cancer
• Phytoceuticals
• TGF-β

• Humans
• Berberine/pharmacology
• Airway Remodeling
• Antioxidants
• Cell Proliferation
• Epithelial Cells

• cancer
• endoglin
• hemostasis
• hereditary hemorrhagic telangiectasia
• hypercholesterolemia
• hyperglycemia
• vascular pathology

Dysregulation of the focal adhesion pathway is present in the three most common forms of glomerular disease, that is, Focal segmental glomerulosclerosis, membranous nephropathy, and minimal change disease. Zyxin is seen to be upregulated in the glomerular compartment of patients with the three most common forms of glomerular disease.

Focal segmental glomerulosclerosis, membranous nephropathy, and minimal change disease are common causes of nephrotic syndrome. Although triggers for these diseases differ, disease progression may share common molecular mechanisms. The aim of this study was to investigate the presence of molecular pathways that are dysregulated across these glomerular diseases.

The gene expression dataset GSE200828 from the Nephrotic Syndrome Study Network study was obtained from the Gene Expression Omnibus database. R and Python packages, Cytoscape software, and online tools (DAVID and STRING) were used to identify core genes and topologically relevant nodes and molecular pathways. Single-cell RNA sequencing analysis was applied to identify the expression patterns of core genes across kidney cell types in glomerular compartments.

A total of 1087 differentially expressed genes were identified, including 691 upregulated genes and 396 downregulated genes, which are common in all three forms of nephrotic syndrome compared with kidney donor controls (FDR P <0.01). A multiapproach bioinformatics analysis narrowed down to 28 similarly dysregulated genes across the three proteinuric glomerulopathies. The most topologically relevant nodes belonged to the adherens junction, focal adhesion, and cytoskeleton pathways, where zyxin covers all of those gene ontology terms.

We report that dysregulation of cell adhesion complexes was present in the three most common forms of glomerular disease. Zyxin could be a biomarker in all three common forms of nephrotic syndrome. If further functional studies confirm its role in their development, zyxin could be a potential therapeutic target.

• chronic nephropathy
• nephrotic syndrome

• Humans
• Adult
• Nephrotic Syndrome/diagnosis
• Nephrotic Syndrome/genetics
• Computational Biology

• angiogenesis
• endoglin
• head and neck tumors
• paraganglioma
• salivary gland tumors

Endoglin (ENG) is expressed on the surface of endothelial cells (ECs) where it efficiently binds circulating BMP9 and BMP10 ligands to initiate activin A receptor like type 1 (ALK1) protein signalling to protect the vascular architecture. Patients heterozygous for ENG or ALK1 mutations develop the vascular disorder known as hereditary haemorrhagic telangiectasia (HHT). Many patients with this disorder suffer from anaemia, and are also at increased risk of stroke and high output heart failure. Recent work using animal models of HHT has revealed new insights into cellular and molecular mechanisms causing this disease. Loss of the ENG (HHT1) or ALK1 (HHT2) gene in ECs leads to aberrant arteriovenous connections or malformations (AVMs) in developing blood vessels. Similar phenotypes develop following combined EC specific loss of SMAD1 and 5, or EC loss of SMAD4. Taken together these data point to the essential role of the BMP9/10-ENG-ALK1-SMAD1/5-SMAD4 pathway in protecting the vasculature from AVMs. Altered directional migration of ECs in response to shear stress and increased EC proliferation are now recognised as critical factors driving AVM formation. Disruption of the ENG/ALK1 signalling pathway also affects EC responses to vascular endothelial growth factor (VEGF) and crosstalk between ECs and vascular smooth muscle cells. It is striking that the vascular lesions in HHT are both localised and tissue specific. Increasing evidence points to the importance of a second genetic hit to generate biallelic mutations, and the sporadic nature of such somatic mutations would explain the localised formation of vascular lesions. In addition, different pro-angiogenic drivers of AVM formation are likely to be at play during the patient’s life course. For example, inflammation is a key driver of vessel remodelling in postnatal life, and may turn out to be an important driver of HHT disease. The current wealth of preclinical models of HHT has led to increased understanding of AVM development and revealed new therapeutic approaches to treat AVMs, and form the topic of this review.

• R01 HL133009 NHLBI NIH HHS
• R01 HL136566 NHLBI NIH HHS
• British Heart Foundation
• National Institutes of Health
• U.S. Department of Defense

• Bone Neoplasms/genetics
• Endoglin/genetics
• Endoglin/metabolism
• Humans
• Matrix Metalloproteinase 14/genetics
• Matrix Metalloproteinase 14/metabolism
• Proteomics
• Receptors, Growth Factor
• Sarcoma, Ewing/pathology
• Signal Transduction

Endothelial cell (EC) dysfunction has been implicated in a variety of pathological conditions. The collection of ECs from patients is typically conducted postmortem or through invasive procedures, such as surgery and interventional procedures, hampering efforts to clarify the role of ECs in disease onset and progression. In contrast, endothelial colony-forming cells (ECFCs), also termed late endothelial progenitor cells, late outgrowth endothelial cells, blood outgrowth endothelial cells, or endothelial outgrowth cells, are obtained in a minimally invasive manner, namely, by the culture of human peripheral blood mononuclear cells in endothelial growth medium. ECFCs resemble mature ECs phenotypically, genetically, and functionally, making them excellent surrogates for ECs. Numerous studies have been performed that examined ECFC function in conditions such as coronary artery disease, diabetes mellitus, hereditary hemorrhagic telangiectasia, congenital bicuspid aortic valve disease, pulmonary arterial hypertension, venous thromboembolic disease, and von Willebrand disease. Here, we provide an updated review of studies using ECFCs that were performed to better understand the pathophysiology of disease. We also discuss the potential of ECFCs as disease biomarkers and the standardized methods to culture, quantify, and evaluate ECFCs and suggest the future direction of research in this field.

• Cardioinformatics
• computational biology
• drug discovery
• precision medicine
• therapeutics

• Cardiovascular Diseases/drug therapy
• Cytoskeleton
• Drug Discovery
• Extracellular Matrix/metabolism
• Humans
• Microtubules

• K12 HL143959 NHLBI NIH HHS

• 3D cell culture
• Adipose stem cells
• Diabetes type 1
• Secretome

Mesenchymal stem/stromal cells or medicinal signaling cells (MSC)-based therapy holds promise as a beneficial strategy for treating knee OA (osteoarthritis), but there is no standardized protocols nor mechanistic understanding. In order to gain a better insight into the human MSC from adipose tissue applied for autologous OA treatment, we performed extensive comparative immunophenotyping of the stromal vascular fraction from lipoaspirate or microfragmented lipoaspirates by polychromatic flow cytometry and investigated the cellular components considered responsible for cartilage regeneration. We found an enrichment of the regenerative cellular niche of the clinically applied microfragmented stromal vascular fraction. Sex-related differences were observed in the MSC marker expression and the ratio of the progenitor cells from fresh lipoaspirate, which, in female patients, contained a higher expression of CD90 on the three progenitor cell types including pericytes, a higher expression of CD105 and CD146 on CD31^highCD34^high endothelial progenitors as well as of CD73 on supra-adventitialadipose stromal cells. Some of these MSC-expression differences were present after microfragmentation and indicated a differential phenotype pattern of the applied MSC mixture in female and male patients. Our results provide a better insight into the heterogeneity of the adipose MSC subpopulations serving as OA therapeutics, with an emphasis on interesting differences between women and men.

• endothelial progenitors
• immunophenotyping
• lipoaspirate
• mesenchymal stem/stromal cells
• microfragmentation
• osteoarthritis
• pericytes
• stromal vascular fraction
• supra-adventitial-adipose stromal cells

• Adipocytes/metabolism
• Adipose Tissue/metabolism
• Adult
• Aged
• Biomarkers/metabolism
• Cartilage/metabolism
• Cell Differentiation/physiology
• Croatia
• Female
• Flow Cytometry/methods
• Humans
• Immunophenotyping/methods
• Male
• Mesenchymal Stem Cells/immunology
• Mesenchymal Stem Cells/metabolism
• Middle Aged
• Osteoarthritis, Knee/immunology
• Osteoarthritis, Knee/metabolism
• Osteoarthritis, Knee/therapy
• Phenotype
• Regeneration/physiology
• Sex Factors
• Stem Cells/metabolism
• Stromal Cells/metabolism
• Stromal Vascular Fraction/immunology
• Stromal Vascular Fraction/metabolism

• Cataracts
• Giant panda, endangered mammals
• RNA-Seq

• ECFC
• HHT1
• TNFα
• cofilin
• endoglin

• Actin Depolymerizing Factors/genetics
• Actin Depolymerizing Factors/metabolism
• Animals
• Cell Membrane Permeability
• Endoglin/genetics
• Endoglin/metabolism
• Endothelial Cells/metabolism
• Endothelial Cells/pathology
• Inflammation/genetics
• Inflammation/metabolism
• Inflammation/pathology
• Lim Kinases/genetics
• Lim Kinases/metabolism
• Mice
• Neovascularization, Pathologic/genetics
• Neovascularization, Pathologic/metabolism
• Neovascularization, Pathologic/pathology

The influence of cultivation on the expression pattern of canine adipose-derived mesenchymal stem cells (cAD-MSCs) surface markers, contributing to, among others, the promotion of growth, proliferation, differentiation and immunomodulatory mechanisms of an excellent therapeutic, is still unknown. To fill the gap, we investigated CD90, CD44, CD73, CD29, CD271, CD105, CD45 and CD14 patterns of expression at the protein level with flow cytometry and mRNA level using a real-time polymerase chain reaction array. Gentle variations of expression occurred during cultivation, along with increased CD90, CD44 and CD29 expression, low and decreasing CD271 and CD73 expression and a decrease of initially high CD105. As expected, CD45 and CD14 were not expressed by cAD-MSCs. Interestingly, we discovered a significant decrease of CD73 expression, compared to early (P1–P3) to late (P4–P6) passages, although the CD73 gene expression was found to be stable. The percentage of positive cells was found to be higher for all positive markers up to P4. As CD73′s one important feature is a modulation from a pro-inflammatory environment to an anti-inflammatory milieu, the expression of CD73 in our conditions indicate the need to consider the time cells spend in vitro before being transplanted into patients, since it could impact their favourable therapeutical properties.

• canine
• flow cytometry
• gene expression
• immunophenotype
• in vitro cultivation
• stem cells

• Animals
• Biomarkers/metabolism
• Cell Differentiation
• Dogs
• Female
• Gene Expression Profiling
• Gene Expression Regulation
• Membrane Proteins/genetics
• Membrane Proteins/metabolism
• Mesenchymal Stem Cells/cytology
• Mesenchymal Stem Cells/metabolism

• CD105
• angiogenesis
• endoglin
• inflammation
• tumor microenvironment
• vessel normalization

• PI19/01630 Instituto de Salud Carlos III
• BES-2014-069277 Ministerio de Economía y Competitividad

A spotlight has been shone on endoglin in recent years due to that fact of its potential to serve as both a reliable disease biomarker and a therapeutic target. Indeed, endoglin has now been assigned many roles in both physiological and pathological processes. From a molecular point of view, endoglin mainly acts as a co-receptor in the canonical TGFβ pathway, but also it may be shed and released from the membrane, giving rise to the soluble form, which also plays important roles in cell signaling. In cancer, in particular, endoglin may contribute to either an oncogenic or a non-oncogenic phenotype depending on the cell context. The fact that endoglin is expressed by neoplastic and non-neoplastic cells within the tumor microenvironment suggests new possibilities for targeted therapies. Here, we aimed to review and discuss the many roles played by endoglin in different tumor types, as well as the strong evidence provided by pre-clinical and clinical studies that supports the therapeutic targeting of endoglin as a novel clinical strategy.

• biomarker
• endoglin
• microenvironment
• targeted therapy
• tumor

• Cytoskeleton
• Hippo
• Junction
• LIMD1
• Mechanotransduction
• Tension

• Actin Cytoskeleton
• Actins
• Adherens Junctions
• Cytoskeleton
• Focal Adhesions
• Vinculin/genetics

• R35 GM131748 NIGMS NIH HHS
• National Institutes of Health
• Rutgers University

Transforming growth factor-β1 (TGF-β1) is a pleiotropic factor sensed by most cells. It regulates a broad spectrum of cellular responses including hematopoiesis. In order to process TGF-β1-responses in time and space in an appropriate manner, there is a tight regulation of its signaling at diverse steps. The downstream signaling is mediated by type I and type II receptors and modulated by the ‘accessory’ receptor Endoglin also termed cluster of differentiation 105 (CD105). Endoglin was initially identified on pre-B leukemia cells but has received most attention due to its high expression on activated endothelial cells. In turn, Endoglin has been figured out as the causative factor for diseases associated with vascular dysfunction like hereditary hemorrhagic telangiectasia-1 (HHT-1), pre-eclampsia, and intrauterine growth restriction (IUPR). Because HHT patients often show signs of inflammation at vascular lesions, and loss of Endoglin in the myeloid lineage leads to spontaneous inflammation, it is speculated that Endoglin impacts inflammatory processes. In line, Endoglin is expressed on progenitor/precursor cells during hematopoiesis as well as on mature, differentiated cells of the innate and adaptive immune system. However, so far only pro-monocytes and macrophages have been in the focus of research, although Endoglin has been identified in many other immune system cell subsets. These findings imply a functional role of Endoglin in the maturation and function of immune cells. Aside the functional relevance of Endoglin in endothelial cells, CD105 is differentially expressed during hematopoiesis, arguing for a role of this receptor in the development of individual cell lineages. In addition, Endoglin expression is present on mature immune cells of the innate (i.e., macrophages and mast cells) and the adaptive (i.e., T-cells) immune system, further suggesting Endoglin as a factor that shapes immune responses. In this review, we summarize current knowledge on Endoglin expression and function in hematopoietic precursors and mature hematopoietic cells of different lineages.

• CD105
• Endoglin
• TGF-β-signaling
• adaptive immunity
• hematopoiesis
• hematopoietic stem cells
• innate immunity

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant genetic disorder that presents with telangiectases in skin and mucosae, and arteriovenous malformations (AVMs) in internal organs such as lungs, liver, and brain. Mutations in ENG (endoglin), ACVRL1 (ALK1), and MADH4 (Smad4) genes account for over 95% of HHT. Localized telangiectases and AVMs are present in different organs, with frequencies which differ among affected individuals. By itself, HHT gene heterozygosity does not account for the focal nature and varying presentation of the vascular lesions leading to the hypothesis of a “second-hit” that triggers the lesions. Accumulating research has identified a variety of triggers that may synergize with HHT gene heterozygosity to generate the vascular lesions. Among the postulated second-hits are: mechanical trauma, light, inflammation, vascular injury, angiogenic stimuli, shear stress, modifier genes, and somatic mutations in the wildtype HHT gene allele. The aim of this review is to summarize these triggers, as well as the functional mechanisms involved.

• ALK1
• Smad4
• angiogenesis
• arteriovenous malformation (AVM)
• cell adhesion
• endoglin
• hereditary hemorrhagic telangiectasia (HHT), second-hit
• inflammation
• shear stress
• somatic mutation
• transforming growth factor beta (TGF-β)
• vascular endothelial growth factor (VEGF)
• vascular injury

The hair follicle is a biological oscillator that alternates growth, regression, and rest phases driven by the sequential activation of the proliferation/differentiation programs of resident stem cell populations. The activation of hair follicle stem cell niches and subsequent entry into the growing phase is mainly regulated by Wnt/β-catenin signalling, while regression and resting phases are mainly regulated by Tgf-β/Bmp/Smad activity. A major question still unresolved is the nature of the molecular switch that dictates the coordinated transition between both signalling pathways. Here we have focused on the role of Endoglin (Eng), a key co-receptor for members of the Tgf-β/Bmp family of growth factors. Using an Eng haploinsufficient mouse model, we report that Eng is required to maintain a correct follicle cycling pattern and for an adequate stimulation of hair follicle stem cell niches. We further report that β-catenin binds to the Eng promoter depending on Bmp signalling. Moreover, we show that β-catenin interacts with Smad4 in a Bmp/Eng-dependent context and both proteins act synergistically to activate Eng promoter transcription. These observations point to the existence of a growth/rest switching mechanism in the hair follicle that is based on an Eng-dependent feedback cross-talk between Wnt/β-catenin and Bmp/Smad signals.

• Adult
• Coronary artery aneurysm
• Endoglin
• Kawasaki disease
• Methylphenidat
• Parvovirus

• Hereditary hemorrhagic telangiectasia
• cytoskeleton
• immune deficiency
• neutrophil extracellular traps

Mesenchymal stem cells (MSCs) possess promising potential in tissue engineering and regenerative medicine. Previous studies demonstrated that spheroid formation of MSCs exhibited improved stemness maintenance and therapeutic potential compared with monolayer culture. To date, various spheroid culture systems have been developed but most of them required low adhesion conditions or special equipment. In this study, we demonstrated that inoculation of dissociated MSCs in TeSR-E8 medium could induce self-assemble spheroid formation in conventional tissue culture polystyrene dishes. Compared with monolayer culture, adipose-derived stem cell (ADSC) spheroids enhanced the proliferation and osteogenic capability of ADSCs compared with monolayer culture. When reseeded in normal serum-containing medium, the expression level of stemness biomarkers was even higher in spheroid-derived ADSCs than monolayer culture. Importantly, spheroid ADSCs could effectively promote the M2 polarization of macrophages both in vitro and in vivo. After transplantation into mouse, spheroid ADSCs improved the survival rate and significantly decreased serum levels of proinflammatory factors IL-1β and TNF-α following LPS challenge. In summary, we developed a 3D spheroid culture system through TeSR-E8 medium without the involvement of low adhesion conditions and special equipment, which provided a practical and convenient method for spheroid formation of MSCs with great potential for stem cell clinical therapy.

• Breast cancer
• Cancer stem cells
• Prognosis
• TRIP6
• Wnt/β-catenin

• National Natural Science Foundation of China

• BMP
• HHT
• TGF-β
• TRIM family
• cancer
• endoglin
• endothelial cells
• galectin family
• preeclampsia
• protein–protein interactions

• Animals
• Blood Proteins
• CHO Cells
• Cricetulus
• Endoglin/metabolism
• Galectin 3/metabolism
• Galectins
• Human Umbilical Vein Endothelial Cells
• Humans
• Protein Array Analysis/methods
• Protein Binding
• Ribonucleoproteins/metabolism

• Angiogenic factors
• F-actin
• Human bone marrow endothelial progenitor cells
• In vitro
• Tight junction proteins

Chronic Thromboembolic Pulmonary Hypertension (CTEPH) is a debilitating disease, for which the underlying pathophysiological mechanisms have yet to be fully elucidated. Occurrence of a pulmonary embolism (PE) is a major risk factor for the development of CTEPH, with non-resolution of the thrombus being considered the main cause of CTEPH. Polymorphisms in the α-chain of fibrinogen have been linked to resistance to fibrinolysis in CTEPH patients, and could be responsible for development and disease progression. However, it is likely that additional genetic predisposition, as well as genetic and molecular alterations occurring as a consequence of tissue remodeling in the pulmonary arteries following a persistent PE, also play an important role in CTEPH. This review summarises the current knowledge regarding genetic differences between CTEPH patients and controls (with or without pulmonary hypertension). Mutations in BMPR2, differential gene and microRNA expression, and the transcription factor FoxO1 have been suggested to be involved in the processes underlying the development of CTEPH. While these studies provide the first indications regarding important dysregulated pathways in CTEPH (e.g., TGF-β and PI3K signaling), additional in-depth investigations are required to fully understand the complex processes leading to CTEPH.

• biomarkers
• chronic thromboembolic pulmonary hypertension
• genetic alterations
• microRNAs
• molecular factors
• mutations
• pathophysiology

Endoglin (ENG) is a transmembrane glycoprotein expressed on endothelial cells that functions as a co-receptor for several ligands of the transforming growth factor beta (TGF-β) family. ENG is also a recognized marker of angiogenesis and mutations in the endoglin gene are responsible for Hereditary Hemorrhagic Telangiectasia (HHT) type 1, a vascular disease characterized by defective angiogenesis, arteriovenous malformations, telangiectasia, and epistaxis. In addition to its involvement in the TGF-β family signaling pathways, several lines of evidence suggest that the extracellular domain of ENG has a role in integrin-mediated cell adhesion via its RGD motif. Indeed, we have described a role for endothelial ENG in leukocyte trafficking and extravasation via its binding to leukocyte integrins. We have also found that ENG is involved in vasculogenic properties of endothelial progenitor cells known as endothelial colony forming cells (ECFCs). Moreover, the binding of endothelial ENG to platelet integrins regulate the resistance to shear during platelet-endothelium interactions under inflammatory conditions. Because of the need for more effective treatments in HHT and the involvement of ENG in angiogenesis, current studies are aimed at identifying novel biological functions of ENG which could serve as a therapeutic target. This review focuses on the interaction between ENG and integrins with the aim to better understand the role of this protein in blood vessel formation driven by progenitor and mature endothelial cells.

• ECFCs
• EPC
• HHT1
• TGF-β
• endoglin
• endothelial progenitors
• integrins

• Endoglin (CD105)
• MVD-CD105 score
• TGF-β auxiliary receptors
• hepatocellular carcinoma
• tumour microvasculature

• Angiogenesis Inhibitors/therapeutic use
• Carcinoma, Hepatocellular/blood supply
• Carcinoma, Hepatocellular/drug therapy
• Carcinoma, Hepatocellular/metabolism
• Carcinoma, Hepatocellular/pathology
• Endoglin/biosynthesis
• Gene Expression Regulation, Neoplastic/drug effects
• Humans
• Liver Neoplasms/blood supply
• Liver Neoplasms/drug therapy
• Liver Neoplasms/metabolism
• Liver Neoplasms/pathology
• Neoplasm Proteins/biosynthesis
• Neovascularization, Pathologic/drug therapy
• Neovascularization, Pathologic/metabolism
• Neovascularization, Pathologic/pathology

• CD73
• SILAC
• cancer stem cell
• cell surface biomarker
• renal cell carcinoma

• BMP
• SMAD
• TGF-β
• activin
• co-receptor

• Activins/chemistry
• Activins/metabolism
• Animals
• Bone Morphogenetic Proteins/chemistry
• Bone Morphogenetic Proteins/metabolism
• Humans
• Models, Molecular
• Protein Binding
• Protein Domains
• Receptors, Transforming Growth Factor beta/chemistry
• Receptors, Transforming Growth Factor beta/metabolism
• Signal Transduction
• Transforming Growth Factor beta/chemistry
• Transforming Growth Factor beta/metabolism

• Activin A receptor like type 1
• Angiogenesis
• Arteriovenous malformation
• Bone morphogenetic protein
• Endoglin
• Hereditary hemorrhagic telangiectasia

• Activin Receptors, Type II/metabolism
• Animals
• Endothelial Cells/metabolism
• Humans
• Receptors, Transforming Growth Factor beta/metabolism
• Signal Transduction/physiology
• Telangiectasia, Hereditary Hemorrhagic/metabolism

• P30 CA054174 NCI NIH HHS
• R01 GM058670 NIGMS NIH HHS
• R01 HL133009 NHLBI NIH HHS
• R01 HL136566 NHLBI NIH HHS
• National Institutes of Health
• University of Pittsburgh Vascular Medicine Institute, the Hemophilia Center of Western Pennsylvania, and the Institute for Transfusion Medicine

Supplemental Digital Content is available in the text.

Endoglin, a transforming growth factor-β superfamily coreceptor, is predominantly expressed in endothelial cells and has essential roles in vascular development. However, whether endoglin is also expressed in vascular smooth muscle cells (VSMCs), especially in vivo, remains controversial. Furthermore, the roles of endoglin in VSMC biology remain largely unknown. Our objective was to examine the expression and determine the function of endoglin in VSMCs during angiogenesis.

Here, we determine that endoglin is robustly expressed in VSMCs. Using CRISPR/CAS9 knockout and short hairpin RNA knockdown in the VSMC/endothelial coculture model system, we determine that endoglin in VSMCs, but not in endothelial cells, promotes VSMCs recruitment by the endothelial cells both in vitro and in vivo. Using an unbiased bioinformatics analysis of RNA sequencing data and further study, we determine that, mechanistically, endoglin mediates VSMC recruitment by promoting VSMC migration and spreading on endothelial cells via increasing integrin/FAK pathway signaling, whereas endoglin has minimal effects on VSMC adhesion to endothelial cells. In addition, we further determine that loss of endoglin in VSMCs inhibits VSMC recruitment in vivo.

These studies demonstrate that endoglin has an important role in VSMC recruitment and blood vessel maturation during angiogenesis and also provide novel insights into how discordant endoglin function in endothelial and VSMCs may regulate vascular maturation and angiogenesis.

• endoglin
• endothelial cells
• integrins
• muscle, smooth, vascular
• signal transduction

• Angiogenesis
• Arterial occlusion
• Arteriogenesis
• Collateral growth
• Endoglin
• Ischemia
• Revascularization
• Vascular remodeling

The first osteogenic cells to attach to a titanium (Ti) implant after placement are the multipotent stromal cells (MSCs) that circulate in the bloodstream and are recruited to the site of tissue damage. The reservoirs of these cells are heterogeneous in nature, consisting of a mixture of cells with varying differentiation abilities. In order to utilise these cells and to reduce the chance of unwanted events during regenerative therapies, the selection of a subset of cells that is truly multipotent is required. The behaviour of these cells has been shown to be altered by modifications to Ti implant surfaces, most notably rough, hydrophilic Ti. These changes in behaviour underpin the differences seen in clinical performance of these surfaces. In this study Human bone marrow derived stromal cells (hBMSCs) have been cultured on modified Ti surfaces in order to analyse these changes in cell behaviour. The results demonstrate the different effects of the surfaces and suggest that one surface selectively enriches the population with osteogenic adult ‘stem cells’ by inducing the cell death of the more differentiated cells. Combined with subsequent expansion in bioreactors before implantation, this may lead to a new source of cells for regenerative therapies.

•

Different titanium surfaces elicit differing responses from bone marrow derived stromal cells.

• Enrichment
• Osteogenic
• Selection
• Stem cells
• Titanium

The deterioration of endothelial structure plays a very important role in the development of vascular diseases. It is believed that endothelial dysfunction starts in the early stage of kidney disease and is a risk factor of an unfavorable cardiovascular prognosis. Because a direct assessment of biological states in endothelial cells is not applicable, the measurement of endothelial microparticles (EMPs) detached from endothelium during activation or apoptosis is thought to be a marker of early vascular disease and endothelial dysfunction in children with chronic kidney disease (CKD). Few studies have shown increased circulating EMPs and its relationship with cardiovascular risk factors in patients with CKD. MPs contain membrane proteins and cytosolic material derived from the cell from which they originate. EMPs having CD144, CD 146, CD31⁺/CD41^-, CD51 and CD105 may be used to evaluate the vascular endothelial cell damage and determine asymptomatic patients who might be at higher risk of developing cardiovascular disease in CKD and renal transplant.

• Endothelial dysfunction
• Endothelial microparticles
• Kidney transplantation
• Chronic kidney disease

• Adipogenesis
• Chondrogenesis
• Human newborn foreskin stem cell
• Neurogenesis
• Osteogenesis

Endoglin is a type III TGFβ auxiliary receptor that is upregulated in endothelial cells during angiogenesis and, when mutated in humans, results in the vascular disease hereditary hemorrhagic telangiectasia (HHT). Though endoglin has been implicated in cell adhesion, the underlying molecular mechanisms are still poorly understood. Here we show endoglin expression in endothelial cells regulates subcellular localization of zyxin in focal adhesions in response to BMP9. RNA knockdown of endoglin resulted in mislocalization of zyxin and altered formation of focal adhesions. The mechanotransduction role of focal adhesions and their ability to transmit regulatory signals through binding of the extracellular matrix are altered by endoglin deficiency. BMP/TGFβ transcription factors, SMADs, and zyxin have recently been implicated in a newly emerging signaling cascade, the Hippo pathway. The Hippo transcription coactivator, YAP1 (yes-associated protein 1), has been suggested to play a crucial role in mechanotransduction and cell-cell contact. Identification of BMP9-dependent nuclear localization of YAP1 in response to endoglin expression suggests a mechanism of crosstalk between the two pathways. Suppression of endoglin and YAP1 alters BMP9-dependent expression of YAP1 target genes CCN1 (cysteine-rich 61, CYR61) and CCN2 (connective tissue growth factor, CTGF) as well as the chemokine CCL2 (monocyte chemotactic protein 1, MCP-1). These results suggest a coordinate effect of endoglin deficiency on cell matrix remodeling and local inflammatory responses. Identification of a direct link between the Hippo pathway and endoglin may reveal novel mechanisms in the etiology of HHT.

• Adaptor Proteins, Signal Transducing/metabolism
• Animals
• Antigens, CD/metabolism
• Chemokine CCL2/metabolism
• Chemokines/metabolism
• Connective Tissue Growth Factor/metabolism
• Cysteine-Rich Protein 61/metabolism
• Endoglin
• Endothelial Cells/metabolism
• Extracellular Matrix/metabolism
• Focal Adhesions/metabolism
• Growth Differentiation Factor 2
• Growth Differentiation Factors/metabolism
• Hippo Signaling Pathway
• Human Umbilical Vein Endothelial Cells
• Humans
• Mice
• Mice, Knockout
• Models, Biological
• Phosphoproteins/metabolism
• Protein Serine-Threonine Kinases/metabolism
• Receptors, CCR2/metabolism
• Receptors, Cell Surface/metabolism
• Signal Transduction
• Smad Proteins/metabolism
• Transcription Factors
• YAP-Signaling Proteins
• Zyxin/metabolism

• P30 GM106391 NIGMS NIH HHS
• R01 HL083151 NHLBI NIH HHS
• HL083151 NHLBI NIH HHS
• R01 HL109652 NHLBI NIH HHS
• HL070865 NHLBI NIH HHS
• 1P30 GM106391 NIGMS NIH HHS
• HL109652 NHLBI NIH HHS
• R01 CA091645 NCI NIH HHS
• P30GM103392 NIGMS NIH HHS
• CA91645 NCI NIH HHS
• P30 GM103392 NIGMS NIH HHS
• R01 HL070865 NHLBI NIH HHS

• 14-3-3
• F-actin organization
• GRIP1
• Trip6
• dendritic morphogenesis
• myosin VI

• CD105
• CD172a
• CD29
• EHV1
• MSC
• pUL56

The homodimeric transmembrane receptor endoglin (CD105) plays an important role in angiogenesis. This is highlighted by mutations in its gene, causing the vascular disorder HHT1. The main role of endoglin function has been assigned to the modulation of transforming growth factor β and bone morphogenetic protein signalling in endothelial cells. Nevertheless, other functions of endoglin have been revealed to be involved in different cellular functions and in other cell types than endothelial cells. Compared to the exploration of its natural function, little experimental data have been gathered about the mode of action of endoglin HHT mutations at the cellular level, especially missense mutations, and to what degree these might interfere with normal endoglin function. In this paper, we have used fluorescence-based microscopic techniques, such as bimolecular fluorescence complementation (BiFC), immunofluorescence staining with the endoglin specific monoclonal antibody SN6, and protein interaction studies by Förster Resonance Energy Transfer (FRET) to investigate the formation and cellular localisation of possible homo- and heterodimers composed of endoglin wild-type and endoglin missense mutant proteins. The results show that all of the investigated missense mutants dimerise with themselves, as well as with wild-type endoglin, and localise, depending on the position of the affected amino acid, either in the rough endoplasmic reticulum (rER) or in the plasma membrane of the cells. We show that the rER retained mutants reduce the amount of endogenous wild-type endoglin on the plasma membrane through interception in the rER when transiently or stably expressed in HMEC-1 endothelial cells. As a result of this, endoglin modulated TGF-β1 signal transduction is also abrogated, which is not due to TGF-β receptor ER trafficking interference. Protein interaction analyses by FRET show that rER located endoglin missense mutants do not perturb protein processing of other membrane receptors, such as TβRII, ALK5 or ALK1.