IGFBP-2 enhances VEGF gene promoter activity and consequent promotion of angiogenesis by neuroblastoma cells

Generation and characterisation of scalable and stable human pluripotent stem cell-derived microvascular-like endothelial cells for cardiac applications

Coronary microvascular disease (CMD) and its progression towards major adverse coronary events pose a significant health challenge. Accurate in vitro investigation of CMD requires a robust cell model that faithfully represents the cells within the cardiac microvasculature. Human pluripotent stem cell-derived endothelial cells (hPSC-ECs) offer great potential; however, they are traditionally derived via differentiation protocols that are not readily scalable and are not specified towards the microvasculature. Here, we report the development and comprehensive characterisation of a scalable 3D protocol enabling the generation of phenotypically stable cardiac hPSC-microvascular-like ECs (hPSC-CMVECs) and cardiac pericyte-like cells. These were derived by growing vascular organoids within 3D stirred tank bioreactors and subjecting the emerging 3D hPSC-ECs to high-concentration VEGF-A treatment (3DV). Not only did this promote phenotypic stability of the 3DV hPSC-ECs; single cell-RNA sequencing (scRNA-seq) revealed the pronounced expression of cardiac endothelial- and microvascular-associated genes. Further, the generated mural cells attained from the vascular organoid exhibited markers characteristic of cardiac pericytes. Thus, we present a suitable cell model for investigating the cardiac microvasculature as well as the endothelial-dependent and -independent mechanisms of CMD. Moreover, owing to their phenotypic stability, cardiac specificity, and high angiogenic potential, the cells described within would also be well suited for cardiac tissue engineering applications.

Culturing Conditions Dictate the Composition and Pathways Enrichment of Human and Rat Perirenal Adipose-Derived Stromal Cells' Secretomes

Understanding the impact of various culturing strategies on the secretome composition of adipose-derived stromal cells (ASC) enhances their therapeutic potential. This study investigated changes in the secretome of perirenal ASC (prASC) under different conditions: normoxia, cytokine exposure, high glucose, hypoxia, and hypoxia with high glucose. Using mass spectrometry and enrichment clustering analysis, we found that normoxia enriched pathways related to extracellular matrix (ECM) organization, platelet degranulation, and insulin-like growth factor (IGF) transport and uptake. Cytokine exposure influenced metabolism, vascular development, and protein processing pathways. High glucose affected the immune system, metabolic processes, and IGF transport and uptake. Hypoxia impacted immune and metabolic processes and protein processing. Combined hypoxia and high glucose influenced the immune system, IGF transport and uptake, and ECM organization. Our findings highlight the potential of manipulating culturing conditions to produce secretomes with distinct protein and functional profiles, tailoring therapeutic strategies accordingly.

The Role of Insulin-like Growth Factor Binding Protein (IGFBP)-2 in DNA Repair and Chemoresistance in Breast Cancer Cells

The role if insulin-like growth factor binding protein-2 (IGFBP-2) in mediating chemoresistance in breast cancer cells has been demonstrated, but the mechanism of action is unclear. This study aimed to further investigate the role of IGFBP-2 in the DNA damage response induced by etoposide in MCF-7, T47D (ER+ve), and MDA-MB-231 (ER-ve) breast cancer cell lines. In the presence or absence of etoposide, IGFBP-2 was silenced using siRNA in the ER-positive cell lines, or exogenous IGFBP-2 was added to the ER-negative MDA-MB-231 cells. Cell number and death were assessed using trypan blue dye exclusion assay, changes in abundance of proteins were monitored using Western blotting of whole cell lysates, and localization and abundance were determined using immunofluorescence and cell fractionation. Results from ER-positive cell lines demonstrated that upon exposure to etoposide, loss of IGFBP-2 enhanced cell death, and this was associated with a reduction in P-DNA-PKcs and an increase in γH2AX. Conversely, with ER-negative cells, the addition of IGFBP-2 in the presence of etoposide resulted in cell survival, an increase in P-DNA-PKcs, and a reduction in γH2AX. In summary, IGFBP-2 is a survival factor for breast cancer cells that is associated with enhancement of the DNA repair mechanism.

Transplantation of Stem Cell Spheroid-Laden 3-Dimensional Patches with Bioadhesives for the Treatment of Myocardial Infarction

Myocardial infarction (MI) is treated with stem cell transplantation using various biomaterials and methods, such as stem cell/spheroid injections, cell sheets, and cardiac patches. However, current treatment methods have some limitations, including low stem cell engraftment and poor therapeutic effects. Furthermore, these methods cause secondary damage to heart due to injection and suturing to immobilize them in the heart, inducing side effects. In this study, we developed stem cell spheroid-laden 3-dimensional (3D) patches (S_3DP) with biosealant to treat MI. This 3D patch has dual modules, such as open pockets to directly deliver the spheroids with their paracrine effects and closed pockets to improve the engraft rate by protecting the spheroid from harsh microenvironments. The spheroids formed within S_3DP showed increased viability and expression of angiogenic factors compared to 2-dimensional cultured cells. We also fabricated gelatin-based tissue adhesive biosealants via a thiol-ene reaction and disulfide bond formation. This biosealant showed stronger tissue adhesiveness than commercial fibrin glue. Furthermore, we successfully applied S_3DP using a biosealant in a rat MI model without suturing in vivo, thereby improving cardiac function and reducing heart fibrosis. In summary, S_3DP and biosealant have excellent potential as advanced stem cell therapies with a sutureless approach to MI treatment.

Identification of key genes modules linking diabetic retinopathy and circadian rhythm

Background

Diabetic retinopathy (DR) is a leading cause of vision loss worldwide. Recent studies highlighted the crucial impact of circadian rhythms (CR) on normal retinopathy in response to the external light cues. However, the role of circadian rhythms in DR pathogenesis and potential investigational drugs remains unclear.

Methods

To investigate the weather CR affects DR, differential expression analysis was employed to identify differentially expressed genes (DEGs) from the GEO database (GSE160306). Functional enrichment analysis was conducted to identify relevant signaling pathways. LASSO regression was utilized to screen pivotal genes. Weighted gene co-expression network anlaysis (WGCNA) was applied to identify different modules. Additionally, we use the Comparative Toxicogenomics Database (CTD) database to search key genes related to drugs or molecular compounds. The diabetic mouse model received three consecutive intraperitoneal injections of streptozotocin (STZ) during 3 successive days.

Results

We initially identified six key genes associated with circadian rhythm in DR, including COL6A3, IGFBP2, IGHG4, KLHDC7A, RPL26P30, and MYL6P4. Compared to normal tissue, the expression levels of COL6A3 and IGFB2 were significantly increased in DR model. Furthermore, we identified several signaling pathways, including death domain binding, insulin-like growth factor I binding, and proteasome binding. We also observed that COL6A3 was positively correlated with macrophages (cor=0.628296895, p=9.96E-08) and Th17 cells (cor=0.665120835, p=9.14E-09), while IGFBP2 showed a negatively correlated with Tgd (cor=-0.459953045, p=0.000247284) and Th2 cells (cor=-0.442269719, p=0.000452875). Finally, we identified four drugs associated with key genes: Resveratrol, Vitamin E, Streptozocin, and Sulindac.

Conclusion

Our findings revealed several key genes related to circadian rhythms and several relevant drugs in DR, providing a novel insight into the mechanism of DR and potential implications for future DR treatment. This study contributes to a better understanding of CR in DR and its implications for future therapeutic interventions.

Canine diffuse large b-cell lymphoma downregulates the activity of CD8 + T-cells through tumor-derived extracellular vesicles

BACKGROUND

Tumor-derived extracellular vesicles (EVs) have been proposed as the essential mediator between host immunity and cancer development. These EVs conduct cellular communication to facilitate tumor growth, enable invasion and metastasis, and shape the favorable tumor microenvironment. Lymphoma is one of the most common hematological malignancies in humans and dogs. Effective T-cell responses are required for the control of these malignancies. However, the immune crosstalk between CD8 + T-cells, which dominates anti-tumor responses, and canine lymphoma has rarely been described.

METHODS

This study investigates the immune manipulating effects of EVs, produced from the clinical cases and cell line of canine B cell lymphoma, on CD8 + T-cells isolated from canine donors.

RESULTS

Lymphoma-derived EVs lead to the apoptosis of CD8 + T-cells. Furthermore, EVs trigger the overexpression of CTLA-4 on CD8 + T-cells, which indicates that EV blockade could serve as a potential therapeutic strategy for lymphoma patients. Notably, EVs transform the CD8 + T-cells into regulatory phenotypes by upregulating their PD-1, PD-L1, and FoxP3 mRNA expression. The regulatory CD8 + T-cells secret the panel of inhibitory cytokines and angiogenic factors and thus create a pro-tumorigenic microenvironment.

CONCLUSION

In summary, the current study demonstrated that the EVs derived from canine B cell lymphoma impaired the anti-tumor activity of CD8 + T-cells and manipulated the possible induction of regulatory CD8 + T-cells to fail the activation of host cellular immunity.

Technical Implications of the Chicken Embryo Chorioallantoic Membrane Assay to Elucidate Neuroblastoma Biology

The chorioallantoic membrane (CAM) can be used as a valuable research tool to examine tumors. The CAM can be used to investigate processes such as migration, invasion, and angiogenesis and to assess novel antitumor drugs. The CAM can be used to establish tumors in a straightforward, rapid, and cost-effective manner via xenotransplantation of cells or tumor tissues with reproducible results; furthermore, the use of the CAM adheres to the three "R" principle, i.e., replace, reduce, and refine. To achieve successful tumor establishment and survival, several technical aspects should be taken into consideration. The complexity and heterogeneity of diseases including neuroblastoma and cancers in general and their impact on human health highlight the importance of preclinical models that help us describe tumor-specific biological processes. These models will not only help in understanding tumor biology, but also allow clinicians to explore therapeutic alternatives that will improve current treatment strategies. In this review, we summarize the technical characteristics as well as the main findings regarding the use of this model to study neuroblastoma for angiogenesis, metastasis, drug sensitivity, and drug resistance.

Angiogenic signaling pathways and anti-angiogenic therapy for cancer

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

Insulin-like growth factor binding Protein-4: A novel indicator of pulmonary arterial hypertension severity and survival

Proteomic analysis of patients with pulmonary arterial hypertension (PAH) has demonstrated significant abnormalities in the insulin-like growth factor axis (IGF). This study proposed to establish associations between a specific binding protein, insulin-like growth factor binding protein 4 (IGFBP4), and PAH severity as well as survival across varying study cohorts. In all cohorts studied, serum IGFBP4 levels were significantly elevated in PAH compared to controls (p < 0.0001). IGFBP4 concentration was also highest in the connective tissue-associated PAH (CTD-PAH) and idiopathic PAH subtypes (876 and 784 ng/mL, median, respectively). After adjustment for age and sex, IGFBP4 was significantly associated with worse PAH severity as defined by a decreased 6-min walk distance (6MWD), New York heart association functional class (NYHA-FC), REVEAL 2.0 score and higher right atrial pressures. In longitudinal analysis provided by one of the study cohorts, IGFBP4 was prospectively significantly associated with a shorter 6MWD, worse NYHA-FC classification, and decreased survival. Cox multivariable analysis demonstrated higher serum IGFBP4 as an independent predictor of survival in the overall PAHB cohort. Therefore, this study established that higher circulating IGFBP4 levels were significantly associated with worse PAH severity, decreased survival and disease progression. Dysregulation of IGF metabolism/growth axis may play a significant role in PAH cardio-pulmonary pathobiology.

circSMARCA5 Is an Upstream Regulator of the Expression of miR-126-3p, miR-515-5p, and Their mRNA Targets, Insulin-like Growth Factor Binding Protein 2 (IGFBP2) and NRAS Proto-Oncogene, GTPase (NRAS) in Glioblastoma

The involvement of non-coding RNAs (ncRNAs) in glioblastoma multiforme (GBM) pathogenesis and progression has been ascertained but their cross-talk within GBM cells remains elusive. We previously demonstrated the role of circSMARCA5 as a tumor suppressor (TS) in GBM. In this paper, we explore the involvement of circSMARCA5 in the control of microRNA (miRNA) expression in GBM. By using TaqMan^® low-density arrays, the expression of 748 miRNAs was assayed in U87MG overexpressing circSMARCA5. Differentially expressed (DE) miRNAs were validated through single TaqMan^® assays in: (i) U87MG overexpressing circSMARCA5; (ii) four additional GBM cell lines (A172; CAS-1; SNB-19; U251MG); (iii) thirty-eight GBM biopsies; (iv) twenty biopsies of unaffected brain parenchyma (UC). Validated targets of DE miRNAs were selected from the databases TarBase and miRTarbase, and the literature; their expression was inferred from the GBM TCGA dataset. Expression was assayed in U87MG overexpressing circSMARCA5, GBM cell lines, and biopsies through real-time PCR. TS miRNAs 126-3p and 515-5p were upregulated following circSMARCA5 overexpression in U87MG and their expression was positively correlated with that of circSMARCA5 (r-values = 0.49 and 0.50, p-values = 9 × 10^-5 and 7 × 10^-5, respectively) in GBM biopsies. Among targets, IGFBP2 (target of miR-126-3p) and NRAS (target of miR-515-5p) mRNAs were positively correlated (r-value = 0.46, p-value = 0.00027), while their expression was negatively correlated with that of circSMARCA5 (r-values = -0.58 and -0.30, p-values = 0 and 0.019, respectively), miR-126-3p (r-value = -0.36, p-value = 0.0066), and miR-515-5p (r-value = -0.34, p-value = 0.010), respectively. Our data identified a new GBM subnetwork controlled by circSMARCA5, which regulates downstream miRNAs 126-3p and 515-5p, and their mRNA targets IGFBP2 and NRAS.

Activation of Piezo1 contributes to matrix stiffness-induced angiogenesis in hepatocellular carcinoma

BACKGROUND

Despite integrin being highlighted as a stiffness-sensor molecule in matrix stiffness-driven angiogenesis, other stiffness-sensor molecules and their mechanosensory pathways related to angiogenesis in hepatocellular carcinoma (HCC) remain obscure. Here, we explored the interplay between Piezo1 and integrin β1 in the mechanosensory pathway and their effects on HCC angiogenesis to better understand matrix stiffness-induced angiogenesis.

METHODS

The role of Piezo1 in matrix stiffness-induced angiogenesis was investigated using orthotopic liver cancer SD rat models with high liver stiffness background, and its clinical significance was evaluated in human HCC tissues. Matrix stiffness-mediated Piezo1 upregulation and activation were assayed using an in vitro fibronectin (FN)-coated cell culture system with different stiffness, Western blotting and Ca²⁺ probe. The effects of shPiezo1-conditioned medium (CM) on angiogenesis were examined by tube formation assay, wound healing assay and angiogenesis array. The underlying mechanism by which Piezo1 participated in matrix stiffness-induced angiogenesis was analyzed by microRNA quantitative real-time polymerase chain reaction (qRT-PCR), matrix stiffness measurement, dual-luciferase reporter assay, ubiquitination assay and co-immunoprecipitation.

RESULTS

Increased matrix stiffness significantly upregulated Piezo1 expression at both cellular and tissue levels, and high expression of Piezo1 indicated an unfavorable prognosis. High matrix stiffness also noticeably enhanced the activation level of Piezo1, similar to its expression level. Piezo1 knockdown significantly suppressed tumor growth, angiogenesis, and lung metastasis of HCC rat models with high liver stiffness background. shPiezo1-CM from HCC cells attenuated tube formation and migration abilities of vascular endothelial cells remarkably, and analysis of differentially expressed pro-angiogenic factors revealed that Piezo1 promoted the expression and secretion of vascular endothelial growth factor (VEGF), CXC chemokine ligand 16 (CXCL16) and insulin-like growth factor binding protein 2 (IGFBP2). Matrix stiffness-caused Piezo1 upregulation/activation restrained hypoxia inducible factor-1α (HIF-1α) ubiquitination, subsequently enhanced the expression of downstream pro-angiogenic factors to accelerate HCC angiogenesis. Besides, collagen 1 (COL1)-reinforced tissue stiffening resulted in more expression of Piezo1 via miR-625-5p.

CONCLUSIONS

This study unravels a new mechanism by which the integrin β1/Piezo1 activation/Ca²⁺ influx/HIF-1α ubiquitination/VEGF, CXCL16 and IGFBP2 pathway participates in matrix stiffness-driven HCC angiogenesis. Simultaneously, a positive feedback regulation loop as stiff matrix/integrin β1/miR-625-5p/Piezo1 and COL1/stiffer matrix mediates matrix stiffness-caused Piezo1 upregulation.

Associations between Insulin-Like Growth Factor Binding Protein-2 and lipoprotein kinetics in men

Low circulating concentrations of insulin-like growth factor binding protein-2 (IGFBP-2) have been associated with dyslipidemia, notably with high triglyceride (TG) levels. However, the determinants by which IGFBP-2 influences lipoprotein metabolism, especially that of TG-rich lipoproteins (TRLs), are poorly understood. Here, we aimed to assess the relationships between IGFBP-2 levels and lipoprotein production and catabolism in human subjects. Fasting IGFBP-2 concentrations were measured in the plasma of 219 men pooled from previous lipoprotein kinetics studies. We analyzed production rate and fractional catabolic rates of TRLapoB-48, and LDL-, IDL-, and VLDLapoB-100 by multicompartmental modeling of l-[5,5,5-D3] leucine enrichment data after a 12 h primed constant infusion in individuals kept in a constant nutritional steady state. Subjects had an average BMI of 30 kg/m², plasma IGFBP-2 levels of 157 ng/ml, and TG of 2.2 mmol/l. After adjustments for age and BMI, IGFBP-2 levels were negatively associated with plasma TG (r = −0.29; P < 0.0001) and positively associated with HDL-cholesterol (r = 0.26; P < 0.0001). In addition, IGFBP-2 levels were positively associated with the fractional catabolic rate of VLDLapoB-100 (r = 0.20; P < 0.01) and IDLapoB-100 (r = 0.19; P < 0.05) and inversely with the production rate of TRLapoB-48 (r = −0.28; P < 0.001). These correlations remained statistically significant after adjustments for age, BMI, and the amount of fat given during the tracer infusion. These findings show that the association between low plasma IGFBP-2 and high TG concentrations could be due to both an impaired clearance of apoB-100-containing VLDL and IDL particles and an increased production of apoB-48-containing chylomicrons. Additional studies are necessary to investigate whether and how IGFBP-2 directly impacts the kinetics of TRL.

Endothelial Dysfunction in the Context of Blood–Brain Barrier Modeling

Here, we discuss pathophysiological approaches to the defining of endothelial dysfunction criteria (i.e., endothelial activation, impaired endothelial mechanotransduction, endothelial-to-mesenchymal transition, reduced nitric oxide release, compromised endothelial integrity, and loss of anti-thrombogenic properties) in different in vitro and in vivo models. The canonical definition of endothelial dysfunction includes insufficient production of vasodilators, pro-thrombotic and pro-inflammatory activation of endothelial cells, and pathologically increased endothelial permeability. Among the clinical consequences of endothelial dysfunction are arterial hypertension, macro- and microangiopathy, and microalbuminuria. We propose to extend the definition of endothelial dysfunction by adding altered endothelial mechanotransduction and endothelial-to-mesenchymal transition to its criteria. Albeit interleukin-6, interleukin-8, and MCP-1/CCL2 dictate the pathogenic paracrine effects of dysfunctional endothelial cells and are therefore reliable endothelial dysfunction biomarkers in vitro, they are non-specific for endothelial cells and cannot be used for the diagnostics of endothelial dysfunction in vivo. Conceptual improvements in the existing methods to model endothelial dysfunction, specifically, in relation to the blood–brain barrier, include endothelial cell culturing under pulsatile flow, collagen IV coating of flow chambers, and endothelial lysate collection from the blood vessels of laboratory animals in situ for the subsequent gene and protein expression profiling. Combined with the simulation of paracrine effects by using conditioned medium from dysfunctional endothelial cells, these flow-sensitive models have a high physiological relevance, bringing the experimental conditions to the physiological scenario.

The Origination of Growth Hormone/Insulin-Like Growth Factor System: A Story From Ancient Basal Chordate Amphioxus

The growth hormone/insulin-like growth factor (GH/IGF) system, also called the pituitary-liver axis, has a somatotrophic role in the body. Although the GH/IGF system has always been regarded as a vertebrate-specific endocrine system, its actual origin remained unknown for a long time. The basal chordate, amphioxus, occupies an evolutionary position between vertebrates and invertebrates. Impressively, most of the members of the GH/IGF system are present in the amphioxus. The GH-like molecule in the amphioxus is mainly expressed in Hatschek's pit. It functions similarly to vertebrate GH and has a GH receptor-like binding partner. The amphioxus IGF-like peptide shows mitogenic activity and an expression pattern resembling that of vertebrate IGF-I. The receptor of IGF-like peptide and IGF binding protein (IGFBP) have also been demonstrated to exist in the amphioxus. These results reveal the origin of the gene families in the GH/IGF system, providing strong evidence that this system emerged in the amphioxus.

Periosteum-derived podoplanin-expressing stromal cells regulate nascent vascularization during epiphyseal marrow development

Bone marrow development and endochondral bone formation occur simultaneously. During endochondral ossification, periosteal vasculatures and stromal progenitors invade the primary avascular cartilaginous anlage, which induces primitive marrow development. We previously determined that bone marrow podoplanin (PDPN)-expressing stromal cells exist in the perivascular microenvironment and promote megakaryopoiesis and erythropoiesis. In this study, we aimed to examine the involvement of PDPN-expressing stromal cells in postnatal bone marrow generation. Using histological analysis, we observed that periosteum-derived PDPN-expressing stromal cells infiltrated the cartilaginous anlage of the postnatal epiphysis and populated on the primitive vasculature of secondary ossification center. Furthermore, immunophenotyping and cellular characteristic analyses indicated that the PDPN-expressing stromal cells constituted a subpopulation of the skeletal stem cell lineage. In vitro xenovascular model cocultured with human umbilical vein endothelial cells and PDPN-expressing skeletal stem cell progenies showed that PDPN-expressing stromal cells maintained vascular integrity via the release of angiogenic factors and vascular basement membrane-related extracellular matrices. We show that in this process, Notch signal activation committed the PDPN-expressing stromal cells into a dominant state with basement membrane-related extracellular matrices, especially type IV collagens. Our findings suggest that the PDPN-expressing stromal cells regulate the integrity of the primitive vasculatures in the epiphyseal nascent marrow. To the best of our knowledge, this is the first study to comprehensively examine how PDPN-expressing stromal cells contribute to marrow development and homeostasis.

Pre-Conditioning with IFN-γ and Hypoxia Enhances the Angiogenic Potential of iPSC-Derived MSC Secretome

Induced pluripotent stem cell (iPSC) derived mesenchymal stem cells (iMSCs) represent a promising source of progenitor cells for approaches in the field of bone regeneration. Bone formation is a multi-step process in which osteogenesis and angiogenesis are both involved. Many reports show that the secretome of mesenchymal stromal stem cells (MSCs) influences the microenvironment upon injury, promoting cytoprotection, angiogenesis, and tissue repair of the damaged area. However, the effects of iPSC-derived MSCs secretome on angiogenesis have seldom been investigated. In the present study, the angiogenic properties of IFN-γ pre-conditioned iMSC secretomes were analyzed. We detected a higher expression of the pro-angiogenic genes and proteins of iMSCs and their secretome under IFN-γ and hypoxic stimulation (IFN-H). Tube formation and wound healing assays revealed a higher angiogenic potential of HUVECs in the presence of IFN-γ conditioned iMSC secretome. Sprouting assays demonstrated that within Coll/HA scaffolds, HUVECs spheroids formed significantly more and longer sprouts in the presence of IFN-γ conditioned iMSC secretome. Through gene expression analyses, pro-angiogenic genes (FLT-1, KDR, MET, TIMP-1, HIF-1α, IL-8, and VCAM-1) in HUVECs showed a significant up-regulation and down-regulation of two anti-angiogenic genes (TIMP-4 and IGFBP-1) compared to the data obtained in the other groups. Our results demonstrate that the iMSC secretome, pre-conditioned under inflammatory and hypoxic conditions, induced the highest angiogenic properties of HUVECs. We conclude that pre-activated iMSCs enhance their efficacy and represent a suitable cell source for collagen/hydroxyapatite with angiogenic properties.

Angiogenic Potential of VEGF Mimetic Peptides for the Biofunctionalization of Collagen/Hydroxyapatite Composites

Currently, the focus on bioinspired concepts for the development of tissue engineering constructs is increasing. For this purpose, the combination of collagen (Coll) and hydroxyapatite (HA) comes closest to the natural composition of the bone. In order to confer angiogenic properties to the scaffold material, vascular endothelial growth factor (VEGF) is frequently used. In the present study, we used a VEGF mimetic peptide (QK) and a modified QK-peptide with a poly-glutamic acid tag (E7-QK) to enhance binding to HA, and analyzed in detail binding efficiency and angiogenic properties. We detected a significantly higher binding efficiency of E7-QK peptides to hydroxyapatite particles compared to the unmodified QK-peptide. Tube formation assays revealed similar angiogenic functions of E7-QK peptide (1µM) as induced by the entire VEGF protein. Analyses of gene expression of angiogenic factors and their receptors (FLT-1, KDR, HGF, MET, IL-8, HIF-1α, MMP-1, IGFBP-1, IGFBP-2, VCAM-1, and ANGPT-1) showed higher expression levels in HUVECs cultured in the presence of 1 µM E7-QK and VEGF compared to those detected in the negative control group without any angiogenic stimuli. In contrast, the expression of the anti-angiogenic gene TIMP-1 showed lower mRNA levels in HUVECs cultured with E7-QK and VEGF. Sprouting assays with HUVEC spheroids within Coll/HA/E7-QK scaffolds showed significantly longer sprouts compared to those induced within Coll/HA/QK or Coll/HA scaffolds. Our results demonstrate a significantly better functionality of the E7-QK peptide, electrostatically bound to hydroxyapatite particles compared to that of unmodified QK peptide. We conclude that the used E7-QK peptide represents an excellently suited biomolecule for the generation of collagen/hydroxyapatite composites with angiogenic properties.

A robust vasculogenic microfluidic model using human immortalized endothelial cells and Thy1 positive fibroblasts

Human umbilical vein endothelial cells (HUVECs) and stromal cells, such as human lung fibroblasts (FBs), have been widely used to generate functional microvascular networks (μVNs) in vitro. However, primary cells derived from different donors have batch-to-batch variations and limited lifespans when cultured in vitro, which hampers the reproducibility of μVN formation. Here, we immortalize HUVECs and FBs by exogenously expressing human telomerase reverse transcriptase (hTERT) to obtain stable endothelial cell and FB sources for μVN formation in vitro. Interestingly, we find that immortalized HUVECs can only form functional μVNs with immortalized FBs from earlier passages but not from later passages. Mechanistically, we show that Thy1 expression decreases in FBs from later passages. Compared to Thy1 negative FBs, Thy1 positive FBs express higher IGFBP2, IGFBP7, and SPARC, which are important for angiogenesis and lumen formation during vasculogenesis in 3D. Moreover, Thy1 negative FBs physically block microvessel openings, reducing the perfusability of μVNs. Finally, by culturing immortalized FBs on gelatin-coated surfaces in serum-free medium, we are able to maintain the majority of Thy1 positive immortalized FBs to support perfusable μVN formation. Overall, we establish stable cell sources for μVN formation and characterize the functions of Thy1 positive and negative FBs in vasculogenesis in vitro.

IGFBP2 Is a Potential Master Regulator Driving the Dysregulated Gene Network Responsible for Short Survival in Glioblastoma Multiforme

Only 2% of glioblastoma multiforme (GBM) patients respond to standard therapy and survive beyond 36 months (long-term survivors, LTS), while the majority survive less than 12 months (short-term survivors, STS). To understand the mechanism leading to poor survival, we analyzed publicly available datasets of 113 STS and 58 LTS. This analysis revealed 198 differentially expressed genes (DEGs) that characterize aggressive tumor growth and may be responsible for the poor prognosis. These genes belong largely to the Gene Ontology (GO) categories “epithelial-to-mesenchymal transition” and “response to hypoxia.” In this article, we applied an upstream analysis approach that involves state-of-the-art promoter analysis and network analysis of the dysregulated genes potentially responsible for short survival in GBM. Binding sites for transcription factors (TFs) associated with GBM pathology like NANOG, NF-κB, REST, FRA-1, PPARG, and seven others were found enriched in the promoters of the dysregulated genes. We reconstructed the gene regulatory network with several positive feedback loops controlled by five master regulators [insulin-like growth factor binding protein 2 (IGFBP2), vascular endothelial growth factor A (VEGFA), VEGF165, platelet-derived growth factor A (PDGFA), adipocyte enhancer-binding protein (AEBP1), and oncostatin M (OSMR)], which can be proposed as biomarkers and as therapeutic targets for enhancing GBM prognosis. A critical analysis of this gene regulatory network gives insights into the mechanism of gene regulation by IGFBP2 via several TFs including the key molecule of GBM tumor invasiveness and progression, FRA-1. All the observations were validated in independent cohorts, and their impact on overall survival has been investigated.

Therapeutic mesenchymal stromal stem cells: Isolation, characterization and role in equine regenerative medicine and metabolic disorders

Mesenchymal stromal cells (MSC) have become a popular treatment modality in equine orthopaedics. Regenerative therapies are especially interesting for pathologies like complicated tendinopathies of the distal limb, osteoarthritis, osteochondritis dissecans (OCD) and more recently metabolic disorders. Main sources for MSC harvesting in the horse are bone marrow, adipose tissue and umbilical cord blood. While the acquisition of umbilical cord blood is fairly easy and non-invasive, extraction of bone marrow and adipose tissue requires more invasive techniques. Characterization of the stem cells as a result of any isolation method, is also a crucial step for the confirmation of the cells' stemness properties; thus, three main characteristics must be fulfilled by these cells, namely: adherence, expression of a series of well-defined differentiation clusters as well as pluripotency. EVs, resulting from the paracrine action of MSCs, also play a key role in the therapeutic mechanisms mediated by stem cells; MSC-EVs are thus largely implicated in the regulation of proliferation, maturation, polarization and migration of various target cells. Evidence that EVs alone represent a complex network 0involving different soluble factors and could then reflect biophysical characteristics of parent cells has fuelled the importance of developing highly specific techniques for their isolation and analysis. All these aspects related to the functional and technical understanding of MSCs will be discussed and summarized in this review.

Thyroid Hormone Enhances Angiogenesis and the Warburg Effect in Squamous Cell Carcinomas

Simple Summary

Cancer cells rewire their metabolism to promote growth, survival, proliferation, and long-term maintenance. Aerobic glycolysis is a prominent trait of many cancers; contextually, glutamine addiction, enhanced glucose uptake and aerobic glycolysis sustain the metabolic needs of rapidly proliferating cancer cells. Thyroid hormone (TH) is a positive regulator of tumor progression and metastatic conversion of squamous cell carcinoma (SCC). Accordingly, overexpression of the TH activating enzyme, D2, is associated with metastatic SCC. The aim of our study was to assess the ability of TH and its activating enzyme in promoting key tracts of cancer progression such as angiogenesis, response to hypoxia and metabolic adaptation. By performing in vivo and in vitro studies, we demonstrate that TH induces VEGF-A in cancer cells and fosters aerobic glycolysis inducing pro-glycolytic mediators, thus implying that TH signal attenuation represents a therapeutic tool to contrast tumor angiogenesis and tumor progression.

Abstract

Cancer angiogenesis is required to support energetic demand and metabolic stress, particularly during conditions of hypoxia. Coupled to neo-vasculogenesis, cancer cells rewire metabolic programs to sustain growth, survival and long-term maintenance. Thyroid hormone (TH) signaling regulates growth and differentiation in a variety of cell types and tissues, thus modulating hyper proliferative processes such as cancer. Herein, we report that TH coordinates a global program of metabolic reprogramming and induces angiogenesis through up-regulation of the VEGF-A gene, which results in the enhanced proliferation of tumor endothelial cells. In vivo conditional depletion of the TH activating enzyme in a mouse model of cutaneous squamous cell carcinoma (SCC) reduces the concentration of TH in the tumoral cells and results in impaired VEGF-A production and attenuated angiogenesis. In addition, we found that TH induces the expression of the glycolytic genes and fosters lactate production, which are key traits of the Warburg effect. Taken together, our results reveal a TH–VEGF-A–HIF1α regulatory axis leading to enhanced angiogenesis and glycolytic flux, which may represent a target for SCC therapy.

Role of IGFBP-2 in oral cancer metastasis

Cancer metastasis is one of most main causes of failure in cancer treatment. Nonetheless, more than half of oral cancer patients were diagnosed as advanced oral cancer with dramatically decreased 5-year survival rate to lower than 20%, while the stages become more advanced. In order to improve oral cancer treatment, the identification of cancer metastatic biomarkers and mechanisms is critical. In the current study, two pairs of oral squamous cell carcinoma lines, OC3/C9, and invasive OC3-I5/C9-I5were used as model systems to investigate invasive mechanism as well as to identify potential therapy-associated targets. Based on our previous proteomic analysis, insulin-like growth factor-binding protein 2 (IGFBP-2) was reported participating in oral cancer metastasis. Subsequent studies have applied interference RNA as well as recombinant protein techniques to confirm the roles of IGFBP-2 in oral cancer metastasis and examine their potency in regulating invasion as well as the mechanism IGFBP-2 involved. The results demonstrated that expression of epithelial-mesenchymal transition (EMT) markers including Twist, Snail1, SIP1, profilin, vimentin, uPA and MMP9 were increased in both OC3-I5 and C9-I5 compared to OC3 and C9 cells, while E-cadherin expression was down-regulated in the OC3-I5 and C9-I5 cells. Moreover, IGFBP-2 is shown to affect not only migration and invasion but also wound healing ability and cell proliferation. Our results also revealed that uPA is a downstream target of IGFBP-2 to intermediate oral cancer metastasis. To sum up, the current studies indicated that elevated IGFBP-2 is strongly correlated with oral cancer metastasis and progression, and that it could potentially serve as a prognostic biomarker as well as an innovative target for the treatment of oral cancer invasion.

Comprehensive Profiling of Secretome Formulations from Fetal- and Perinatal Human Amniotic Fluid Stem Cells

We previously reported that c-KIT+ human amniotic-fluid derived stem cells obtained from leftover samples of routine II trimester prenatal diagnosis (fetal hAFS) are endowed with regenerative paracrine potential driving pro-survival, anti-fibrotic and proliferative effects. hAFS may also be isolated from III trimester clinical waste samples during scheduled C-sections (perinatal hAFS), thus offering a more easily accessible alternative when compared to fetal hAFS. Nonetheless, little is known about the paracrine profile of perinatal hAFS. Here we provide a detailed characterization of the hAFS total secretome (i.e., the entirety of soluble paracrine factors released by cells in the conditioned medium, hAFS-CM) and the extracellular vesicles (hAFS-EVs) within it, from II trimester fetal- versus III trimester perinatal cells. Fetal- and perinatal hAFS were characterized and subject to hypoxic preconditioning to enhance their paracrine potential. hAFS-CM and hAFS-EV formulations were analyzed for protein and chemokine/cytokine content, and the EV cargo was further investigated by RNA sequencing. The phenotype of fetal- and perinatal hAFS, along with their corresponding secretome formulations, overlapped; yet, fetal hAFS showed immature oxidative phosphorylation activity when compared to perinatal ones. The profiling of their paracrine cargo revealed some differences according to gestational stage and hypoxic preconditioning. Both cell sources provided formulations enriched with neurotrophic, immunomodulatory, anti-fibrotic and endothelial stimulating factors, and the immature fetal hAFS secretome was defined by a more pronounced pro-vasculogenic, regenerative, pro-resolving and anti-aging profile. Small RNA profiling showed microRNA enrichment in both fetal- and perinatal hAFS-EV cargo, with a stably- expressed pro-resolving core as a reference molecular signature. Here we confirm that hAFS represents an appealing source of regenerative paracrine factors; the selection of either fetal or perinatal hAFS secretome formulations for future paracrine therapy should be evaluated considering the specific clinical scenario.

ONC201 Shows Potent Anticancer Activity Against Medullary Thyroid Cancer via Transcriptional Inhibition of RET, VEGFR2, and IGFBP2

Gain-of-function point mutations in the receptor tyrosine kinase RET, a driver oncogene in medullary thyroid carcinoma (MTC), prevent apoptosis through inhibition of ATF4, a critical transcriptional regulator of endoplasmic reticulum stress. However, the critical regulatory mechanisms driving RET-dependent oncogenesis remain elusive, and there is a clinical need to identify a transcriptional RET inhibitor. Here, we found that RET depletion decreased IGFBP2 and VEGFR2 mRNA and protein expression in MTC cells. IGFBP2 knockdown decreased cell survival and migration of MTC cells. In patients, IGFBP2 expression increased in metastatic MTC, and high IGFBP2 associated with poor overall survival. VEGFR2 protein levels were positively associated with RET expression in primary tumors, and VEGF-mediated increased cell viability was RET dependent. The small-molecule ONC201 treatment of MTC cells caused apoptotic cell death, decreased transcription of RET, VEGFR2, IGFBP2, increased mRNA levels of ATF4, and ATF4 target genes including DDIT3, BBC3, DUSP8, MKNK2, KLF9, LZTFL1, and SESN2 Moreover, IGFBP2 depletion increased ONC201-induced cell death. ONC201 inhibited tumor growth at a well-tolerated dose of 120 mg/kg/week administered by oral gavage and decreased MTC xenograft cell proliferation and angiogenesis. The protein levels of RET, IGFBP2, and VEGFR2 were decreased in ONC201-treated xenografts. Our study uncovered a novel ONC201 mechanism of action through regulation of RET and its targets, VEGFR2 and IGFBP2; this mechanism could be translated into the clinic and represent a promising strategy for the treatment of all patients with MTC, including those with TKI-refractory disease and other cancer with RET abnormalities.

Broadly effective metabolic and immune recovery with C5 inhibition in CHAPLE disease

Complement hyperactivation, angiopathic thrombosis and protein-losing enteropathy (CHAPLE disease) is a lethal disease caused by genetic loss of the complement regulatory protein CD55, leading to overactivation of complement and innate immunity together with immunodeficiency due to immunoglobulin wasting in the intestine. We report in vivo human data accumulated using the complement C5 inhibitor eculizumab for the medical treatment of patients with CHAPLE disease. We observed cessation of gastrointestinal pathology together with restoration of normal immunity and metabolism. We found that patients rapidly renormalized immunoglobulin concentrations and other serum proteins as revealed by aptamer profiling, re-established a healthy gut microbiome, discontinued immunoglobulin replacement and other treatments and exhibited catch-up growth. Thus, we show that blockade of C5 by eculizumab effectively re-establishes regulation of the innate immune complement system to substantially reduce the pathophysiological manifestations of CD55 deficiency in humans.

Protein Microarrays for Ocular Diseases

The eye is a multifaceted organ organized in several compartments with particular properties that reflect their diverse functions. The prevalence of ocular diseases is increasing, mainly because of its relationship with aging and of generalized lifestyle changes. However, the pathogenic molecular mechanisms of many common eye pathologies remain poorly understood. Considering the unquestionable importance of proteins in cellular processes and disease progression, proteomic techniques, such as protein microarrays, represent a valuable approach to analyze pathophysiological protein changes in the ocular environment. This technology enables to perform multiplex high-throughput protein expression profiling with minimal sample volume requirements broadening our knowledge of ocular proteome network in eye diseases.In this review, we present a brief summary of the main types of protein microarrays (antibody microarrays, reverse-phase protein microarrays, and protein microarrays) and their application for protein change detection in chronic ocular diseases such as dry eye, age-related macular degeneration, diabetic retinopathy, and glaucoma. The validation of these specific protein changes in eye pathologies may lead to the identification of new biomarkers, depiction of ocular disease pathways, and assistance in the diagnosis, prognosis, and development of new therapeutic options for eye pathologies.

Pediatric pulmonary hypertension: insulin-like growth factor-binding protein 2 is a novel marker associated with disease severity and survival

BACKGROUND

Insulin-like growth factors (IGFs), and their binding proteins (IGFBPs), play a significant role in cardiovascular function and may influence the pathobiology of PAH. We determined the diagnostic and prognostic value of IGF1 and IGFBP2 in pediatric PAH.

METHODS

Serum was analyzed by ELISA for IGF1 and IGFBP2 in pediatric PAH subjects from the NHLBI PAH Biobank (PAHB, n = 175) and a cohort of asthmatic subjects (n = 46, age 0-21 years) as a chronic pediatric pulmonary disease control. Biomarkers were analyzed with demographic and clinical variables for PAH severity.

RESULTS

Serum IGF1 was significantly lower in PAH compared to controls, while IGFBP2 was elevated in PAH subjects compared to controls. In the PAHB, IGF1 was negatively associated with mPAP and PVR, while IGFBP2 was positively associated with PVR and negatively associated with cardiac output and 6-min walk distance. Higher IGFBP2 levels were associated with use of prostacyclin therapy. IGFBP2 was associated with death, transplant, or palliative shunt with a Cox proportional hazard ratio of 8.8 (p < 0.001) but not IGF1 (p = 0.13).

CONCLUSIONS

Circulating IGFBP2 is a novel marker for pediatric PAH, which is associated with worse functional status, and survival. IGF axis dysregulation may be an important mechanistic target in pediatric pulmonary arterial hypertension.

IMPACT

Pediatric pulmonary hypertension is a severe disease, with poorly understood pathobiology. There are few studies looking at the pathobiology of pulmonary hypertension only in children. The IGF axis is dysregulated in pediatric pulmonary arterial hypertension. IGF axis dysregulation, with increased IGFBP2, is associated with worse clinical outcomes in pediatric pulmonary artery hypertension. IGF axis dysregulation gives new insight into the disease process and may be a mechanistic or therapeutic target.

Co-Culture of Primary Human Coronary Artery and Internal Thoracic Artery Endothelial Cells Results in Mutually Beneficial Paracrine Interactions

Although saphenous veins (SVs) are commonly used as conduits for coronary artery bypass grafting (CABG), internal thoracic artery (ITA) grafts have significantly higher long-term patency. As SVs and ITA endothelial cells (ECs) have a considerable level of heterogeneity, we suggested that synergistic paracrine interactions between CA and ITA ECs (HCAECs and HITAECs, respectively) may explain the increased resistance of ITA grafts and adjacent CAs to atherosclerosis and restenosis. In this study, we measured the gene and protein expression of the molecules responsible for endothelial homeostasis, pro-inflammatory response, and endothelial-to-mesenchymal transition in HCAECs co-cultured with either HITAECs or SV ECs (HSaVECs) for an ascending duration. Upon the co-culture, HCAECs and HITAECs showed augmented expression of endothelial nitric oxide synthase (eNOS) and reduced expression of endothelial-to-mesenchymal transition transcription factors Snail and Slug when compared to the HCAEC–HSaVEC model. HCAECs co-cultured with HITAECs demonstrated an upregulation of HES1, a master regulator of arterial specification, of which the expression was also exclusively induced in HSaVECs co-cultured with HCAECs, suggestive of their arterialisation. In addition, co-culture of HCAECs and HITAECs promoted the release of pro-angiogenic molecules. To conclude, co-culture of HCAECs and HITAECs results in reciprocal and beneficial paracrine interactions that might contribute to the better performance of ITA grafts upon CABG.

Insulin-like growth factor binding protein-2: a new circulating indicator of pulmonary arterial hypertension severity and survival

BACKGROUND

Pulmonary arterial hypertension (PAH) is a fatal disease that results from cardio-pulmonary dysfunction with the pathology largely unknown. Insulin-like growth factor binding protein 2 (IGFBP2) is an important member of the insulin-like growth factor family, with evidence suggesting elevation in PAH patients. We investigated the diagnostic and prognostic value of serum IGFBP2 in PAH to determine if it could discriminate PAH from healthy controls and if it was associated with disease severity and survival.

METHODS

Serum IGFBP2 levels, as well as IGF1/2 levels, were measured in two independent PAH cohorts, the Johns Hopkins Pulmonary Hypertension program (JHPH, N = 127), NHLBI PAHBiobank (PAHB, N = 203), and a healthy control cohort (N = 128). The protein levels in lung tissues were determined by western blot. The IGFBP2 mRNA expression levels in pulmonary artery smooth muscle cells (PASMC) and endothelial cells (PAEC) were assessed by RNA-seq, secreted protein levels by ELISA. Association of biomarkers with clinical variables was evaluated using adjusted linear or logistic regression and Kaplan-Meier analysis.

RESULTS

In both PAH cohorts, serum IGFBP2 levels were significantly elevated (p < 0.0001) compared to controls and discriminated PAH from controls with an AUC of 0.76 (p < 0.0001). A higher IGFBP2 level was associated with a shorter 6-min walk distance (6MWD) in both cohorts after adjustment for age and sex (coefficient - 50.235 and - 57.336 respectively). Cox multivariable analysis demonstrated that higher serum IGFBP2 was a significant independent predictor of mortality in PAHB cohort only (HR, 3.92; 95% CI, 1.37-11.21). IGF1 levels were significantly increased only in the PAHB cohort; however, neither IGF1 nor IGF2 had equivalent levels of associations with clinical variables compared with IGFBP2. Western blotting shown that IGFBP2 protein was significantly increased in the PAH vs control lung tissues. Finally, IGFBP2 mRNA expression and secreted protein levels were significantly higher in PASMC than in PAEC.

CONCLUSIONS

IGFBP2 protein expression was increased in the PAH lung, and secreted by PASMC. Elevated circulating IGFBP2 was associated with PAH severity and mortality and is a potentially valuable prognostic marker in PAH.

Synergistic Effect of Combined Artesunate and Tetramethylpyrazine in Experimental Cerebral Malaria

Intravenous artesunate is effective against cerebral malaria (CM), but high mortality and neurological sequelae in survivors are inevitable. We investigated the effect of combined artesunate and tetramethylpyrazine using mouse models of experimental cerebral malaria (ECM). Artesunate + tetramethylpyrazine reduced microvascular blockage and improved neurological function, including the rapid murine coma and behavior scale (RMCBS), leading to improved survival and reduced pathology in ECM. This combination downregulated the expression of adhesion molecules and sequestration of parasitized red blood cells (pRBCs), increased cerebral blood flow, nerve growth factor (b-NGF), vascular endothelial growth factor A (VEGF-A), and neurotrophin (brain-derived neurotrophic factor (BDNF), neurotrophic factor-3 (NT-3)) levels, and alleviated hippocampal neuronal damage and astrocyte activation. Down- (n = 128) and upregulated (n = 64) proteins were identified in the artesunate group, while up- (n = 217) and downregulated (n = 177) proteins were identified in the artesunate + tetramethylpyrazine group, presenting a significantly altered proteome profile. KEGG analysis showed that 166 differentially expressed proteins were enriched in the Art group and 234, in the artesunate + tetramethylpyrazine group. The neuroprotective effects of artesunate + tetramethylpyrazine were mainly related to proteins involved in axon development and transportation between blood and brain. These results suggested that artesunate + tetramethylpyrazine could be a potential adjuvant therapy against CM, but this will have to be confirmed in future studies and trials.

Activity of the human immortalized endothelial progenitor cell line HEPC-CB.1 supporting in vitro angiogenesis

The human HEPC-CB.1 cell line with many characteristics of endothelial progenitor cells (EPC) was tested for its proangiogenic properties as a potentially therapeutic compound. HEPC-CB.1 cells’ potential to differentiate into endothelial cells was revealed after treating the cells with a mixture of ATRA, cAMP and VEGF, as shown by the reduced expression levels of CD133, CD271 and CD90 antigens, augmentation of CD146 and CD31, and a decrease in cell clonogenicity. The cooperation of HEPC-CB.1 with the endothelial cell line HSkMEC.2 resulted in the formation of a common network. Tube formation was significantly more effective when resulting from HEPC-CB.1 and HSkMEC.2 cell co-culture as compared to a monoculture of each cell line. The exocrine mechanism of HEPC-CB.1 and HSkMEC.2 cross talk by secreted factors was evidenced using the HEPC-CB.1 supernatant to increase the efficacy of HSkMEC.2 tube formation. The proangiogenic factors produced by HEPC-CB.1 were identified using cytokine antibody array. Out of 120 examined factors, the HEPC-CB.1 cell line produced 63, some with known angiogenic activity. As in vivo the angiogenic process occurs at low oxygen tension, it was observed that in hypoxia, the production of defined factors was augmented. The presented results demonstrate that HEPC-CB.1 cells are able to both cooperate and integrate in a newly formed network and produce factors that help the network formation. The results suggest that HEPC-CB.1 cells are indeed endothelial progenitors and may prove to be an effective tool in regenerative medicine.

Insulin-Like Growth Factor Binding Protein-2 Promotes Proliferation and Predicts Poor Prognosis in Hepatocellular Carcinoma

Background

Insulin-like growth factor binding protein-2 (IGFBP2) levels are significantly increased in the plasma of hepatocellular carcinoma (HCC) patients. However, the correlation between IGFBP2 levels and clinical parameters and the exact role of IGFBP2 in HCC are unclear. In this study, we identified the role and potential molecular mechanisms of IGFBP2 in HCC.

Materials and Methods

ELISA assays were used to detect plasma IGFBP2 levels in HCC patients and healthy controls, and the correlations with patients’ clinicopathological data were analyzed. The CCK8 assay was used to explore cell proliferation. Luciferase reporter, co-immunoprecipitation, and immunofluorescence assays were used to demonstrate the molecular mechanism of IGFBP2 in HCC.

Results

Plasma IGFBP2 levels were determined blindly in 37 HCC patients and 37 matched healthy controls. The mean plasma IGFBP2 concentrations in HCC patients were higher than in healthy controls, and IGFBP2 levels in HCC were positively correlated with the degree of differentiation, tumor size, metastasis, and portal venous invasion. Exogenous IGFBP2 activated integrin β1 and thus induced the combination and colocalization of activated integrin β1 and p-FAK, which promoted the phosphorylation of FAK, Erk, and Elk1, eventually inducing EGR1-mediated proliferation of the HCC cell lines HepG2 and HCCLM3. Meanwhile, neutralization of integrin β1 inhibited IGFBP2-induced FAK, Erk, Elk1, and EGR1 activation.

Conclusion

Taken together, these results indicated that exogenous IGFBP2 promoted the integrin β1/FAK/Erk/Elk1/EGR1 pathway, which stimulated the proliferation of HCC cells. Plasma IGFBP2 could be a novel prognostic biomarker for HCC patients.

Polygonum multiflorum extract support hair growth by elongating anagen phase and abrogating the effect of androgen in cultured human dermal papilla cells

Background

Dermal papilla cells (DPCs) play a key role in hair growth among the various cell types in hair follicles. Especially, DPCs determine the fate of hair follicle such as anagen to telogen transition and play a pivotal role in androgenic alopecia (AGA). This study was performed to elucidate the hair growth promoting effects of Polygonum multiflorum extract (PM extract) in cultured human DPCs and its underlying mechanisms.

Methods

The effects of PM extract on cultured DPCs were investigated. Cell viability and mitochondrial activity were measured by CCK-8 and JC-1 analysis, respectively. Western blotting, dot blotting, ELISA analysis, immunocytochemistry and real-time PCR analysis were also performed to elucidate the changes in protein and mRNA levels induced by PM extract. 3D cultured DPC spheroids were constructed for mimicking the in vivo DPs. The hair growth stimulatory effect of PM extract was evaluated using human hair follicle organ culture model.

Results

PM extract increased the viability and mitochondrial activity in cultured human DPCs in a dose dependent manner. The expression of Bcl2, an anti-apoptotic protein expressed dominantly in anagen was significantly increased and that of BAD, a pro-apoptotic protein expressed in early catagen was decreased by PM extract in cultured DPCs and/or 3D DPC spheroid culture. PM extract also decreased the expression of catagen inducing protein, Dkk-1. Growth factors including IGFBP2, PDGF and VEGF were increased by PM extract, revealed by dot blot protein analysis. We also have found that PM extract could reverse the androgenic effects of dihydrotestosterone (DHT), the most potent androgen. Finally, PM extract prolonged the anagen of human hair follicles by inhibiting catagen entry in human hair follicle organ culture model.

Conclusion

Our data strongly suggest that PM extract could promote hair growth by elongating the anagen and/or delaying the catagen induction of hair follicles through activation of DPCs.

Intracellular Insulin-like growth factor binding protein 2 (IGFBP2) contributes to the senescence of keratinocytes in psoriasis by stabilizing cytoplasmic p21

Psoriasis is a chronic Th1/Th17 lymphocytes-mediated inflammatory skin disease, in which epidermal keratinocytes exhibit a peculiar senescent state, resistance to apoptosis and the acquisition of senescence-associated secretory phenotype (SASP). SASP consists of the release of soluble factors, including IGFBPs, that exert extracellular and intracellular functions in IGF-dependent or independent manner.In this report, we investigated the expression and function of IGFBP2 in senescent keratinocytes isolated from the skin of patients with plaque psoriasis. We found that IGFBP2 is aberrantly expressed and released by these cells in vivo, as well as in vitro in keratinocyte cultures undergoing progressive senescence, and it associates with the cyclin-dependent kinase inhibitors p21 and p16 expression. For the first time, we provide evidence for a dual action of IGFBP2 in psoriatic keratinocytes during growth and senescence processes. While extracellular IGFBP2 counter-regulates IGF-induced keratinocyte hyper-proliferation, intracellular IGFBP2 inhibits apoptosis by interacting with p21 and protecting it from ubiquitin-dependent degradation. Indeed, we found that cytoplasmic p21 sustains anti-apoptotic processes, by inhibiting pro-caspase 3 cleavage and JNK phosphorylation in senescent psoriatic keratinocytes. As a consequence, abrogation of p21, as well as that of IGFBP2, found to stabilize cytoplasmic p21 levels, lead to the restoration of apoptosis mechanisms in psoriatic keratinocytes, commonly observed in healthy cells.

Estrogen Stimulation of Pleiotrophin Enhances Osteoblast Differentiation and Maintains Bone Mass in IGFBP-2 Null Mice

Insulin-like growth factor binding protein-2 (IGFBP-2) stimulates osteoblast differentiation but only male Igfbp2 null mice have a skeletal phenotype. The trophic actions of IGFBP-2 in bone are mediated through its binding to receptor tyrosine phosphatase beta (RPTPβ). Another important ligand for RPTPβ is pleiotrophin (PTN), which also stimulates osteoblast differentiation. We determined the change in PTN and RPTPβ in Igfbp2-/- mice. Analysis of whole bone mRNA in wild-type and knockout mice revealed increased expression of Ptn. Rptpβ increased in gene-deleted animals with females having greater expression than males. Knockdown of PTN expression in osteoblasts in vitro inhibited differentiation, and addition of PTN to the incubation medium rescued the response. Estradiol stimulated PTN secretion and PTN knockdown blocked estradiol-stimulated differentiation. PTN addition to IGFBP-2 silenced osteoblast stimulated differentiation, and an anti-fibronectin-3 antibody, which inhibits PTN binding to RPTPβ, inhibited this response. Estrogen stimulated PTN secretion and downstream signaling in the IGFBP-2 silenced osteoblasts and these effects were inhibited with anti-fibronectin-3. Administration of estrogen to wild-type and Igfbp2-/- male mice stimulated an increase in both areal bone mineral density and trabecular bone volume fraction but the increase was significantly greater in the Igfbp2-/- animals. Estrogen also stimulated RPTPβ expression in the null mice. We conclude that loss of IGFBP-2 expression is accompanied by upregulation of PTN and RPTPβ expression in osteoblasts, that the degree of increase is greater in females due to estrogen secretion, and that this compensatory change may account for some component of the maintenance of normal bone mass in female mice.

Nuclear localization and actions of the insulin-like growth factor 1 (IGF-1) system components: Transcriptional regulation and DNA damage response

Insulin-like growth factor (IGF) system stimulates growth, proliferation, and regulates differentiation of cells in a tissue-specific manner. It is composed of two insulin-like growth factors (IGF-1 and IGF-2), six insulin-like growth factor-binding proteins (IGFBPs), and two insulin-like growth factor receptors (IGF-1R and IGF-2R). IGF actions take place mostly through the activation of the plasma membrane-bound IGF-Rs by the circulating ligands (IGFs) released from the IGFBPs that stabilize their levels in the serum. This review focuses on the IGF-1 part of the system. The IGF-1 gene, which is expressed mainly in the liver as well as in other tissues, comprises six alternatively spliced exons that code for three protein isoforms (pro-IGF-1A, pro-IGF-1B, and pro-IGF-1C), which are processed to mature IGF-1 and E-peptides. The IGF-1R undergoes autophosphorylation, resulting in a signaling cascade involving numerous cytoplasmic proteins such as AKT and MAPKs, which regulate the expression of target genes. However, a more complex picture of the axis has recently emerged with all its components being translocated to the nuclear compartment. IGF-1R takes part in the regulation of gene expression by forming transcription complexes, modifying the activity of chromatin remodeling proteins, and participating in DNA damage tolerance mechanisms. Four IGFBPs contain a nuclear localization signal (NLS), which targets them to the nucleus, where they regulate gene expression (IGFBP-2, IGFBP-3, IGFBP-5, IGFBP-6) and DNA damage repair (IGFBP-3 and IGFBP-6). Last but not least, the IGF-1B isoform has been reported to be localized in the nuclear compartment. However, no specific molecular actions have been assigned to the nuclear pro-IGF-1B or its derivative EB peptide. Therefore, further studies are needed to shed light on their nuclear activity. These recently uncovered nuclear actions of different components of the IGF-1 axis are relevant in cancer cell biology and are discussed in this review.

Deregulated expression of Elastin Microfibril Interfacer 2 (EMILIN2) in gastric cancer affects tumor growth and angiogenesis

Gastric cancer is a frequent human tumor and often a lethal disease. Targeted therapy for gastric carcinomas is far behind vis-à-vis other solid tumors, primarily because of the paucity of cancer-driving mutations that could be efficiently and specifically targeted by current therapy. Thus, there is a need to discover actionable pathways/proteins and new diagnostic and prognostic biomarkers. In this study, we explored the role of the extracellular matrix glycoprotein EMILIN2, Elastin Microfibril Interfacer 2, in a cohort of gastric cancer patients. We discovered that EMILIN2 expression was consistently suppressed in gastric cancer and high expression levels of this glycoprotein were linked to abnormal vascular density. Furthermore, we found that EMILIN2 had a dual effect on gastric carcinoma cells: on one hand, it decreased tumor cell proliferation by triggering apoptosis, and on the other hand, it evoked the production of a number of cytokines involved in angiogenesis and inflammation, such as IL-8. Collectively, our findings posit EMILIN2 as an important onco-regulator exerting pleiotropic effects on the gastric cancer microenvironment.

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EMILIN2 is localized in the gastric lamina propria and its expression is down-regulated in gastric cancer.

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High levels of EMILIN2 associate with elevated vascular density.

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EMILIN2 impairs the proliferation of gastric cancer cells by evoking apoptosis.

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Surprisingly, EMILIN2 triggers the expression of pro-angiogenic and pro-inflammatory cytokines.

Metabolite therapy guided by liquid biopsy proteomics delays retinal neurodegeneration

Background

Neurodegenerative diseases are incurable disorders caused by progressive neuronal cell death. Retinitis pigmentosa (RP) is a blinding neurodegenerative disease that results in photoreceptor death and progresses to the loss of the entire retinal network. We previously found that proteomic analysis of the adjacent vitreous served as way to indirectly biopsy the retina and identify changes in the retinal proteome.

Methods

We analyzed protein expression in liquid vitreous biopsies from autosomal recessive (ar)RP patients with PDE6A mutations and arRP mice with Pde6ɑ mutations. Proteomic analysis of retina and vitreous samples identified molecular pathways affected at the onset of photoreceptor death. Based on affected molecular pathways, arRP mice were treated with a ketogenic diet or metabolites involved in fatty-acid synthesis, oxidative phosphorylation, and the tricarboxylic acid (TCA) cycle.

Findings

Dietary supplementation of a single metabolite, ɑ-ketoglutarate, increased docosahexaeonic acid levels, provided neuroprotection, and enhanced visual function in arRP mice. A ketogenic diet delayed photoreceptor cell loss, while vitamin B supplementation had a limited effect. Finally, desorption electrospray ionization mass spectrometry imaging (DESI-MSI) on ɑ-ketoglutarate-treated mice revealed restoration of metabolites that correlated with our proteomic findings: uridine, dihydrouridine, and thymidine (pyrimidine and purine metabolism), glutamine and glutamate (glutamine/glutamate conversion), and succinic and aconitic acid (TCA cycle).

Interpretation

This study demonstrates that replenishing TCA cycle metabolites via oral supplementation prolongs retinal function and provides a neuroprotective effect on the photoreceptor cells and inner retinal network.

Funding

NIH grants [R01EY026682, R01EY024665, R01EY025225, R01EY024698, R21AG050437, P30EY026877, 5P30EY019007, R01EY018213, F30EYE027986, T32GM007337, 5P30CA013696], NSF grant CHE-1734082.

IGFBP2: integrative hub of developmental and oncogenic signaling network

Insulin-like growth factor (IGF) binding protein 2 (IGFBP2) was discovered and identified as an IGF system regulator, controlling the distribution, function, and activity of IGFs in the pericellular space. IGFBP2 is a developmentally regulated gene that is highly expressed in embryonic and fetal tissues and markedly decreases after birth. Studies over the last decades have shown that in solid tumors, IGFBP2 is upregulated and promotes several key oncogenic processes, such as epithelial-to-mesenchymal transition, cellular migration, invasion, angiogenesis, stemness, transcriptional activation, and epigenetic programming via signaling that is often independent of IGFs. Growing evidence indicates that aberrant expression of IGFBP2 in cancer acts as a hub of an oncogenic network, integrating multiple cancer signaling pathways and serving as a potential therapeutic target for cancer treatment.

Decellularized brain matrix enhances macrophage polarization and functional improvements in rat spinal cord injury

Spinal cord injury (SCI) is a devastating lesion lacking effective treatment options currently available in clinics. The inflammatory process exacerbates the extent of the lesion through a secondary injury mechanism, where proinflammatory classically activated macrophages (M1) are prevalent at the lesion site. However, the polarized alternatively activated anti-inflammatory macrophages (M2) are known to play an important role in wound healing and regeneration following SCI. Herein, we introduce porcine brain decellularized extracellular matrix (dECM) to modulate the macrophages in the injured spinal cord. The hydrogels with collagen and dECM at various dECM concentrations (1, 5, and 8 mg/ml) were used to cultivate primary macrophages and neurons. The dECM hydrogels were shown to promote the polarization of macrophages toward M2 phase and the neurite outgrowth of cortical and hippocampal neurons. When the dECM hydrogels were applied to rat SCI models, the proportion of M1 and M2 macrophages in the injured spinal cord was substantially altered. When received dECM concetration of 5 mg/ml, the expression of molecules associated with M2 (CD206, arginase1, and IL-10) was significantly increased. Consistently, the population of total macrophages and cavity area were substantially reduced in the dECM-treated groups. As a result, the locomotor functions of injured spinal cord, as assessed by BBB and ladder scoring, were significantly improved. Collectively, the porcine brain dECM with optimal concentration promotes functional recovery in SCI models through the activation of M2 macrophages, suggesting the promising use of the engineered hydrogels in the treatment of acute SCI. STATEMENT OF SIGNIFICANCE: Spinal cord injury (SCI) is a devastating lesion, lacking effective treatment options currently available in clinics. Here we delineated that the treatment of injured spinal cord with porcine brain decellularized matrix-based hydrogels for the first time, and could modulate the macrophage polarization and the ultimate functional recovery. When appropriate formulations were applied to a contused spinal cord model in rats, the decellularized matrix hydrogels shifted the macrophages to polarize to pro-regenerative M2 phenotype, decreased the size of lesion cavity, and finally promoted the locomotor functions until 8 weeks following the injury. We consider this work can significantly augment the matrix(biomaterial)-based therapeutic options, as an alternative to drug or cell-free approaches, for the treatment of acute injury of spinal cord.

Role of Matrix Metalloproteinases in Angiogenesis and Cancer

During angiogenesis, new vessels emerge from existing endothelial lined vessels to promote the degradation of the vascular basement membrane and remodel the extracellular matrix (ECM), followed by endothelial cell migration, and proliferation and the new generation of matrix components. Matrix metalloproteinases (MMPs) participate in the disruption, tumor neovascularization, and subsequent metastasis while tissue inhibitors of metalloproteinases (TIMPs) downregulate the activity of these MMPs. Then, the angiogenic response can be directly or indirectly mediated by MMPs through the modulation of the balance between pro- and anti-angiogenic factors. This review analyzes recent knowledge on MMPs and their participation in angiogenesis.

Insulin-like Growth Factor Binding Protein 2 predicts mortality risk in heart failure

BACKGROUND

Insulin-like Growth Factor Binding Protein 2 (IGFBP2) showed greater heart failure (HF) diagnostic accuracy than the "grey zone" B-type natriuretic peptides, and may have prognostic utility as well.

OBJECTIVES

To determine if IGFBP2 provides independent information on cardiovascular mortality in HF.

METHODS

A retrospective study of 870 HF patients from 3 independent international cohorts. Presentation IGFBP2 plasma levels were measured by ELISA, and patients were followed from 1 year (Maastricht, Netherlands) to 6 years (Atlanta, GA, USA and Toulouse, France). Multivariate analysis, Net Reclassification Improvement (NRI) and Integrated Discrimination Improvement (IDI) were performed in the 3 cohorts. The primary outcome was cardiovascular mortality.

RESULTS

In multivariate Cox proportional hazards analysis, the highest quartile of IGFBP2 was associated with mortality in the Maastricht cohort (adjusted hazard ratio 1.69 (95% CI, 1.18-2.41), p = 0.004) and in the combined Atlanta and Toulouse cohorts (adjusted hazard ratio 2.04 (95%CI, 1.3-3.3), p = 0.003). Adding IGFBP2 to a clinical model allowed a reclassification of adverse outcome risk in the Maastricht cohort (NRI = 18.7% p = 0.03; IDI = 3.9% p = 0.02) and with the Atlanta/Toulouse patients (NRI of 40.4% p = 0.01, 31,2% p = 0.04, 31.5% p = 0,02 and IDI of 2,9% p = 0,0005, 3.1% p = 0,0005 and 4,2%, p = 0.0005, for a follow-up of 1, 2 and 3 years, respectively).

CONCLUSION

In 3 international cohorts, IGFBP2 level is a strong prognostic factor for cardiovascular mortality in HF, adding information to natriuretic monitoring and usual clinical markers, that should be further prospectively evaluated for patients' optimized care.

IGFBP2 promotes immunosuppression associated with its mesenchymal induction and FcγRIIB phosphorylation in glioblastoma

Immunotherapy shows a promise for treating glioblastoma (GBM), the most malignant and immunosuppressive glioma. The mesenchymal phenotype of cancer cells was frequently reported to be associated with their induction of immunosuppression within the cancer microenvironment. Overexpressed insulin-like growth factor binding protein 2 (IGFBP2) promotes GBM cell migration and invasion, and contributes to glioma progression and cancer recurrence and poor survival in GBM. However, whether IGFBP2 can induce immunosuppression in GBM was not reported yet. Thus, the study applied a syngeneic mouse GBM model, human GBM samples, and cancer-immune cell co-culture experiments to investigate the effect of IGFBP2 on GBM exposed immune cells and its association with the mesenchymal induction. We found that IGFBP2 promoted the mesenchymal feature of GBM cells. The inhibition of IGFBP2 relieved immunosuppression by increasing CD8⁺ T and CD19⁺ B cells and decreasing CD163⁺ M2 macrophages. Further, the IGFBP2-promoted immunosuppression was associated with its induction of the mesenchymal feature of GBM cells and the inhibitory phosphorylated FcγRIIB of GBM exposed immune cells. Blocking IGFBP2 suppressed tumor growth and improved survival of tumor bearing mice in the mouse GBM model. These findings support the notion that targeting the IGFBP2 may present an effective immunotherapeutic strategy for mesenchymal GBMs.

Serum IGFBP2 Level Is a New Candidate Biomarker of Severe Malnutrition in Advanced Lung Cancer

Objectives: This study aimed to analyze and evaluate serum insulin-like growth factor-binding protein 2 (IGFBP2) levels as a new biomarker of severe malnutrition in patients with advanced lung cancer.Design and methods: This prospective study involved 59 patients with advanced lung cancer. We detected serum IGFBP2 level by using enzyme-linked immunosorbent assay and analyzed its relationship to clinical characteristics, nutritional status, Glasgow prognostic score (GPS), and survival. Serum albumin and C-reactive protein (CRP) levels were measured, and nutritional status was assessed using Patient-Generated Subjective Global Assessment (PG-SGA). The best cutoff point value for serum IGFBP2 level was established using receiver operating characteristic analysis. Kaplan-Meier method was utilized to analyze the survival curves.Results: Serum IGFBP2 levels were elevated in patients with advanced lung cancer and severe malnutrition. The best cutoff value for serum IGFBP2 level was determined at 363 ng/ml, which could diagnose severe malnutrition with 73.3% sensitivity and 70.5% specificity and was found to be related to albumin, CRP, and GPS. Patients whose serum IGFBP2 levels were higher than 363 ng/ml had poor survival outcome.Conclusion: This study demonstrates the remarkably association between higher serum level of IGFBP2 and severe malnutrition, albumin, CRP, GPS, and survival. Hence, serum IGFBP2 level can be used as a potential biomarker for diagnosis of severe malnutrition in patients with advanced lung cancer.

Effect of IGFBP2 Overexpression on the Expression of Fatty Acid Synthesis Genes in Primary Cultured Chicken Hepatocytes

The effects of insulin-like growth factor binding protein 2 (IGFBP2) on the expression of fatty acid synthesis regulators and triglyceride production were investigated in primary cultured chicken hepatocytes. The full-length chicken IGFBP2 coding region was synthesized by overlap extension PCR and cloned into the pcDNA3.1 vector. An in situ digestion method was used to prepare the chicken hepatocytes. Primary chicken hepatocytes were maintained in monolayer culture. Real-time PCR was used to detect changes in the expression of IGFBP2, PPARG, IGF1, IGF1R, APOAI, and LFABP, after the overexpression of IGFBP2 in chicken hepatocytes. Triglyceride production and glucose content were also evaluated using triglyceride and glucose analysis methods. The expression level of IGFBP2 increased after transfection of the IGFBP2-containing vector. The expression levels of PPARG, IGF1, and IGF1R also increased in cultured chicken hepatocytes after the overexpression of IGFBP2, whereas the expression of LFABP and APOAI decreased. Triglyceride production in primary cultured chicken hepatocytes increased after the overexpression of IGFBP2. These results suggest that IGFBP2 is involved in lipogenesis, increasing both the expression of fatty acid synthesis regulators, and triglyceride production in primary cultured chicken hepatocytes.

Bone marrow pericyte dysfunction in individuals with type 2 diabetes

AIMS/HYPOTHESIS

Previous studies have shown that diabetes mellitus destabilises the integrity of the microvasculature in different organs by damaging the interaction between pericytes and endothelial cells. In bone marrow, pericytes exert trophic functions on endothelial cells and haematopoietic cells through paracrine mechanisms. However, whether bone marrow pericytes are a target of diabetes-induced damage remains unknown. Here, we investigated whether type 2 diabetes can affect the abundance and function of bone marrow pericytes.

METHODS

We conducted an observational clinical study comparing the abundance and molecular/functional characteristics of CD146⁺ pericytes isolated from the bone marrow of 25 individuals without diabetes and 14 individuals with uncomplicated type 2 diabetes, referring to our Musculoskeletal Research Unit for hip reconstructive surgery.

RESULTS

Immunohistochemistry revealed that diabetes causes capillary rarefaction and compression of arteriole size in bone marrow, without changing CD146⁺ pericyte counts. These data were confirmed by flow cytometry on freshly isolated bone marrow cells. We then performed an extensive functional and molecular characterisation of immunosorted CD146⁺ pericytes. Type 2 diabetes caused a reduction in pericyte proliferation, viability, migration and capacity to support in vitro angiogenesis, while inducing apoptosis. AKT is a key regulator of the above functions and its phosphorylation state is reportedly reduced in the bone marrow endothelium of individuals with diabetes. Surprisingly, we could not find a difference in AKT phosphorylation (at either Ser473 or Thr308) in bone marrow pericytes from individuals with and without diabetes. Nonetheless, the angiocrine signalling reportedly associated with AKT was found to be significantly downregulated, with lower levels of fibroblast growth factor-2 (FGF2) and C-X-C motif chemokine ligand 12 (CXCL12), and activation of the angiogenesis inhibitor angiopoietin 2 (ANGPT2). Transfection with the adenoviral vector carrying the coding sequence for constitutively active myristoylated AKT rescued functional defects and angiocrine signalling in bone marrow pericytes from diabetic individuals. Furthermore, an ANGPT2 blocking antibody restored the capacity of pericytes to promote endothelial networking.

CONCLUSIONS/INTERPRETATION

This is the first demonstration of pericyte dysfunction in bone marrow of people with type 2 diabetes. An altered angiocrine signalling from pericytes may participate in bone marrow microvascular remodelling in individuals with diabetes.

Insulin-like growth factor binding proteins and angiogenesis: from cancer to cardiovascular disease

Angiogenesis is a tightly regulated activity that is vital during embryonic development and for normal physiological repair processes and reproduction in healthy adults. Pathological angiogenesis is a driving force behind a variety of diseases including cancer and retinopathies, and inhibition of angiogenesis is a therapeutic option that has been the subject of much research, with several inhibitory agents now available for medical therapy. Conversely, therapeutic angiogenesis has been mooted as having significant potential in the treatment of ischemic conditions such as angina pectoris and peripheral arterial disease, but so far there has been less translation from lab to bedside. The insulin-like growth factor binding proteins (IGFBP) are a family of seven proteins essential for the binding and transport of the insulin-like growth factors (IGF). It is being increasingly recognised that IGFBPs have a significant role beyond simply modulating IGF activity, with evidence of both IGF dependent and independent actions through a variety of mechanisms. Moreover, the action of the IGFBPs can be stimulatory or inhibitory depending on the cell type and environment. Specifically the IGFBPs have been heavily implicated in angiogenesis, both pathological and physiological, and they have significant promise as targeted cell therapy agents for both pathological angiogenesis inhibition and therapeutic angiogenesis following ischemic injury. In this short review we will explore the current understanding of the individual impact of each IGFBP on angiogenesis, and the pathways through which these effects occur.

IGFBP2 promotes salivary adenoid cystic carcinoma metastasis by activating the NF-κB/ZEB1 signaling pathway

Metastasis is a major cause of poor prognosis in patients suffered with salivary adenoid cystic carcinoma (SACC), in which many factors are implicated. In this study, we identified that IGFBP2, overexpressed in SACC, correlated positively with perineural invasion or metastasis and indicated worse outcome. Moreover, IGFBP2 overexpression could dramatically improve motility and invasion capacity of SACC cells in vitro. Mechanically, IGFBP2 enhanced expression of ZEB1 in a NF-κB (p65)-dependent manner and then promoted epithelial-mesenchymal transition (EMT) in SACC. In addition, IGFBP2 mutation in the nuclear localization signal could impede nuclear translocation of p65, lower ZEB1 expression, and abrogate the EMT process. In xenograft models, IGFBP2 overexpression promoted lung and liver metastases of SACC cells; while if nuclear IGFBP2 was reduced, the formation of metastases in lung and liver was weakened. Together, these results for the first time demonstrate that IGFBP2 plays an important role in invasion and metastasis of SACC through the NF-κB/ZEB1 signaling pathway and IGFBP2 may be a novel biomarker and target for SACC.