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Decellularized and de-epithelialized placenta membranes have widely been used as scaffolds and grafts in tissue engineering and regenerative medicine. Exceptional pro-angiogenic and biomechanical properties and low immunogenicity have made the amniochorionic membrane a unique substrate which provides an enriched niche for cellular growth. Herein, an optimized combination of enzymatic solutions (based on streptokinase) with mechanical scrapping is used to remove the amniotic epithelium and chorion trophoblastic layer, which resulted in exposing the basement membranes of both sides without their separation and subsequent damages to the in-between spongy layer. Biomechanical and biodegradability properties, endothelial proliferation capacity, and in vivo pro-angiogenic capabilities of the substrate were also evaluated. Histological staining, immunohistochemistry (IHC) staining for collagen IV, and scanning electron microscope demonstrated that the underlying amniotic and chorionic basement membranes remained intact while the epithelial and trophoblastic layers were entirely removed without considerable damage to basement membranes. The biomechanical evaluation showed that the scaffold is suturable. Proliferation assay, real-time polymerase chain reaction for endothelial adhesion molecules, and IHC demonstrated that both side basement membranes could support the growth of endothelial cells without altering endothelial characteristics. The dorsal skinfold chamber animal model indicated that both side basement membranes could promote angiogenesis. This bi-sided substrate with two exposed surfaces for cultivating various cells would have potential applications in the skin, cardiac, vascularized composite allografts, and microvascular tissue engineering., (© 2021. The Author(s).)

Background: Bevacizumab, an anti-vascular endothelial growth factor (VEGF) antibody, is a new treatment approach for radionecrosis. In our study, we compared the prophylactic and therapeutic usage of a promising agent, ramipril (an angiotensin-converting enzyme inhibitor), with that of bevacizumab for reducing radiation-induced brain injury after high-dose stereotactic radiosurgery (SRS)., Methods: A total of 60 Wistar rats were used. The rats were irradiated with a single dose of 50 Gy using a Leksell Gamma Knife device. Bevacizumab and ramipril were administered in the prophylactic protocol (starting the first day of SRS) and in the therapeutic protocol (starting the fourth week of SRS). Their usage was continued until 12 weeks, and the right frontal lobes of the rats were examined histologically (hematoxylin and eosin stain) and immunohistochemically (hypoxia-inducible factor [HIF]-1α, VEGF, and CD31 antibody expression)., Results: The expression of VEGF, HIF-1α, and CD31 had significantly increased at 12 weeks after SRS compared with the control group. The addition of bevacizumab or ramipril to SRS significantly mitigated the histological severity of radiation injury and the expression of VEGF, HIF-1α, and CD31. However, the prophylactic use of bevacizumab and ramipril seemed to be more effective than therapeutic administration. Our results also revealed that the greatest benefit was achieved with the use of prophylactic administration of bevacizumab compared with other treatment protocols., Conclusions: Ramipril might be a promising agent for patients with radionecrosis. Clinical studies are required to investigate the effective and safe doses of ramipril, which is an inexpensive, well-tolerated drug that can cross the blood-brain barrier., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: Nicorandil exerts a protective effect against coronary microvascular dysfunction in acute myocardial infarction (AMI) patients. However, the mechanism and effect of nicorandil in hyperhomocysteinemia (HHcy) AMI patients remain unclear., Methods: C57/BL6 mice with mild to moderate HHcy and human coronary artery endothelial cells (HCAECs) cotreated with HHcy (1 mmol/L) for 24 h and hypoxia for 6 h were selected as models. Small animal ultrasound detection was used to compare cardiac function. CD31 immunofluorescence staining and tomato lectin staining were used to assess the number of microcirculation changes in vivo. MTT, tube formation and western blotting assays were used to evaluate the effect of nicorandil on HCAECs and the PI3K/Akt/eNOS pathway., Results: The results showed that nicorandil improved cell viability and p-PI3K/PI3K, p-Akt/Akt, and p-eNOS/eNOS expression in the vitro HHcy and hypoxia models. The beneficial effects of nicorandil on HCAECs could be inhibited by the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 and the nitric oxide synthase (NOS) inhibitor L-NAME. In vivo, nicorandil improved the left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) in the post-HHcy + MI model, and the levels of CD31 and tomato lectin expression were higher in the nicorandil treatment group. The effectiveness of nicorandil was inhibited in the PI3K and L-NAME groups., Conclusion: The results suggest that nicorandil improves Hcy-induced coronary microvascular dysfunction through the PI3K/Akt/eNOS signalling pathway., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2020 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)

Cell proliferation and angiogenesis are of utmost importance for healing to take place. The KI67 and EGFR proteins are markers of cell proliferation, while CD31 and factor VIII are markers of angiogenesis. To elucidate the mechanism responsible for delayed healing of the gastric injury in old age, we analyzed the expression of these markers in rats of different months during the healing of an acetic acid-induced gastric ulcer. Male Wistar rats (aged 3, 6, 12, and 18 months) divided into four groups, according to their ages, formed the experimental animals. Stomach tissue samples were collected on days 3, 7, 14, and 21 after induction for assessment of ulcer healing. The area of gastric mucosa healed was inversely proportional to age. The expression of markers of proliferation (KI67 and EGFR) and angiogenesis (factor VIII and CD31) decreased significantly ( p < 0.05) in older rats when compared with younger ones (3 months > six months > 12 months > 18 months) on days 7, 14, and 21 after induction of gastric ulcer. This study revealed that the slower gastric ulcer healing rate in older rats might be due to reduced epithelial cell proliferation and angiogenic activities., Competing Interests: The authors wish to declare that there are no conflicts of interest., (Copyright © 2020 A. Folorunsho Ajayi and S. Babafemi Olaleye.)

Connexins (Cxs) are membrane-spanning proteins which enable flow of information important for kidney homeostasis. Changes in their spatiotemporal patterning characterize blood vessel abnormalities and chronic kidney diseases (CKD). We analysed spatiotemporal expression of Cx37, Cx40, Cx43 and Cx45 in nephron and glomerular cells of developing, postnatal kidneys, and nephrotic syndrome of the Finnish type (CNF) by using immunohistochemistry, statistical methods and electron microscopy. During kidney development, strong Cx45 expression in proximal tubules and decreasing expression in glomeruli was observed. In developing distal nephron, Cx37 and Cx40 showed moderate-to-strong expression, while weak Cx43 expression gradually increased. Cx45/Cx40 co-localized in mesangial and granular cells. Cx43 /Cx45 co-localized in podocytes, mesangial and parietal epithelial cells, and with podocyte markers (synaptopodin, nephrin). Different Cxs co-expressed with endothelial (CD31) and VSMC (α -SMA) markers in vascular walls. Peak signalling of Cx37, Cx43 and Cx40 accompanied kidney nephrogenesis, while strongest Cx45 signalling paralleled nephron maturation. Spatiotemporal Cxs patterning indicate participation of Cx45 in differentiation of proximal tubules, and Cx43, Cx37 and Cx40 in distal tubules differentiation. CNF characterized disorganized Cx45 expression in proximal tubules, increased Cx43 expression in distal tubules and overall elevation of Cx40 and Cx37, while Cx40 co-localized with increased number of interstitial myofibroblasts.

Background and Purpose: This study aimed to investigate the immunohistochemical expression of CD31 and podoplanin in order to examine angiogenesis and lymphangiogenesis, respectively in common malignant tumors of salivary glands., Materials and Methods: Forty formalin-fixed, paraffinated blocks (20 adenoid cystic carcinoma and 20 mucoepidermoid carcinoma blocks) were selected from the medical archives of Amir A'lam Hospital of Tehran, Iran. Sections from the blocks were stained by CD31 and D2-40 markers via immunohistochemistry. Clinical and demographic information was extracted from the patients' records., Findings: There was a significant difference between tumors in terms of intratumoral microvessel density (MVD) (P< 0.001), total MVD (P< 0.001), and intratumoral lymphatic vessel density (LVD) (P= 0.011). In mucoepidermoid carcinoma, intratumoral MVD and LVD were greater than peritumoral MVD and LVD (P= 0.001 and P< 0.001, respectively). In mucoepidermoid carcinoma, there was no relationship between histological grade with MVD (total, intratumoral or peritumoral) or LVD (total, intratumoral or peritumoral) (P> 0.05). A similar finding was reported with respect to the histopathological grade of adenoid cystic carcinoma (P> 0.05)., Conclusion: The higher level of angiogenesis and lymphangiogenesis in mucoepidermoid carcinoma, specifically at the center of tumor, compared to adenoid cystic carcinoma, may be attributed to differences in the clinical behaviors and metastasis of tumors. Moreover, considering the high LVD at the center of tumor in mucoepidermoid carcinoma and infrequency of metastasis to regional lymph nodes in adenoid cystic carcinoma, it can play a significant role in metastasis to regional lymph nodes.

Introduction: Pterygium is a conjunctival fibrovascular tissue growth on the cornea. The pathogenesis of pterygium involves several factors such as the presence of active angiogenic factors. Expansion of the lymphatic microvasculature has also been hypothesized. This study examines the activity of the angiogenic/lymphangiogenic factor VEGF and the expression of vascular and lymphatic endothelial proteins in pterygia and normal conjunctival tissues., Material and Methods: Primary grade 2 pterygium (n=20) and normal conjunctiva (n=20) biopsies were obtained during surgery after written informed consent. mRNA expression for CD31, podoplanin, and VEGF (isoforms VEGF-A and VEGF-165) were determined by qRT-PCR. Tissue samples were also processed for immunohistochemical techniques to examine the lymphatic and vascular endothelium (anti-D2-40, anti-CD31 respectively) and VEGF-A and VEGF-C levels and distribution., Results: VEGF-A gene expression levels failed to differ between the healthy and pterygium tissues. However, expression of its more angiogenic isoform, VEGF-165, was significantly higher in the pterygia. Immunohistochemistry revealed the greater presence of VEGF-A, compared to VEGF-C, in pterygium than conjunctiva, both in blood vessels and extracellular matrix. In addition, pterygia showed higher expression levels of the endothelial junction protein CD31. Lymphatic marker D2-40 expression was slightly augmented in this pathological tissue. The ratio between blood and lymphatic vessel counts was 1.05 in the normal conjunctiva and 3-fold this value in pterygium., Conclusion: In pterygium, while both lymphangiogenesis and angiogenesis take place, the formation of new blood vessels is the most relevant event, correlating with the increased expression of vascular endothelial CD31 and an elevated blood/lymphatic vessel ratio. The presence of high levels of VEGF-A in both vessel networks and extracellular matrix in human pterygium tissue may have a major impact on angiogenesis in this pathological tissue.

Objectives: To determine whether circulating endothelial cells from septic shock patients and from nonseptic shock patients are transformed in activated fibroblast by changing the expression level of endothelial and fibrotic proteins, whether the level of the protein expression change is associated with the amount of administered resuscitation fluid, and whether this circulating endothelial cell protein expression change is a biomarker to predict sepsis survival., Design: Prospective study., Setting: Medical-surgical ICUs in a tertiary care hospital., Patients: Forty-three patients admitted in ICU and 22 healthy volunteers., Interventions: None., Measurements and Main Results: Circulating mature endothelial cells and circulating endothelial progenitor cells from septic shock and nonseptic shock patients showed evidence of endothelial fibrosis by changing the endothelial protein expression pattern. The endothelial proteins were downregulated, whereas fibroblast-specific markers were increased. The magnitude of the expression change in endothelial and fibrotic proteins was higher in the septic shock nonsurvivors patients but not in nonseptic shock. Interestingly, the decrease in the endothelial protein expression was correlated with the administered resuscitation fluid better than the Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores in the septic shock nonsurvivors patients but not in nonseptic shock. Notably, the significant difference between endothelial and fibrotic protein expression indicated a nonsurvival outcome in septic shock but not in nonseptic shock patients. Remarkably, area under the receiver operating characteristic curve analysis showed that endothelial protein expression levels predicted the survival outcome better than the Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores in septic shock but not in nonseptic shock patients., Conclusions: Circulating endothelial cells from septic shock patients are acutely converted into fibroblasts. Endothelial and fibrotic protein expression level are associated with resuscitation fluid administration magnitude and can be used as biomarkers for an early survival diagnosis of sepsis.

Cancer chemotherapy can cause significant damage to the bone marrow (BM) microvascular (sinusoidal) system. Investigations must now address whether and how BM sinusoidal endothelial cells (SECs) can be protected during chemotherapy. Herein we examined the potential protective effects of genistein, a soy-derived flavonoid, against BM sinusoidal damage caused by treatment with methotrexate (MTX). The groups of young adult rats were gavaged daily with genistein (20 mg/kg) or placebo. After 1 week, rats also received daily injections of MTX (0.75 mg/kg) or saline for 5 days and were killed after a further 4 days. Histological analyses showed that BM sinusoids were markedly dilated ( p < 0.001) in the MTX-alone group but were unaffected or less dilated in the genistein+MTX group. In control rats, genistein significantly enhanced expression of vascular endothelial growth factor (VEGF; p < 0.01), particularly in osteoblasts, and angiogenesis marker CD31 ( p < 0.001) in bone. In MTX-treated rats, genistein suppressed MTX-induced apoptosis of BM SECs ( p < 0.001 vs MTX alone group) and tended to increase expression of CD31 and VEGF ( p < 0.05). Our in vitro studies showed that genistein in certain concentrations protected cultured SECs from MTX cytotoxic effects. Genistein enhanced tube formation of cultured SECs, which is associated with its ability to induce expression of endothelial nitric oxide synthase and production of nitric oxide. These data suggest that genistein can protect BM sinusoids during MTX therapy, which is associated, at least partially, with its indirect effect of promoting VEGF expression in osteoblasts and its direct effect of enhancing nitric oxide production in SECs., (© 2018 Wiley Periodicals, Inc.)

The sinusoidal endothelial cells present in the liver (LSECs) are tipically characterized by the presence of pores (fenestrae). During some pathological conditions LSECs undergo "capillarization", a process characterized by loss of fenestrations and acquisition of a vascular phenotype. In chronic liver disease capillarization has been reported to precede the development of fibrosis. LSECs modification in the setting of HCV infection is currently poorly investigated. Considering that HCV accounts for important changes in hepatocytes and in view of the intimate connection between hepatocytes and LSECs, here we set out to study in great detail the LSECs modifications in individuals with HCV-dependent chronic hepatitis. Electron microscopy analysis, and evaluation of CD32, CD31 and caveolin-1 expression showed that in HCV infection LSECs display major morphological changes but maintain their phenotypical identity. Capillarization was observed only in cases at initial stages of fibrosis. Our findings showed that the severity of LSECs modifications appears to be correlated with hepatocytes damage and fibrosis stage providing novel insight in the pathogenesis of HCV-chronic hepatitis.

Chondrocytes play an essential role in fracture healing by producing cartilage, which forms an anlage for endochondral ossification that stabilizes the healing fracture callus. More recently it has been appreciated that chondrocytes have the capacity to produce factors that may affect the healing process. We examined the role of chondrocytes in angiogenesis during fracture healing and the role of the transcription factor forkhead box-O 1 (FOXO1), which upregulates wound healing in soft tissue. Closed fractures were induced in experimental mice with lineage-specific FOXO1 deletion by Cre recombinase under the control of a collagen-2α1 promoter element (Col2α1Cre + FOXO1 L/L ) and Cre recombinase negative control littermates containing flanking loxP sites (Col2α1Cre - FOXO1 L/L ). Experimental mice had significantly reduced CD31 + new vessel formation. Deletion of FOXO1 in chondrocytes in vivo suppressed the expression of vascular endothelial growth factor-A (VEGFA) at both the protein and mRNA levels. Overexpression of FOXO1 in chondrocytes in vitro increased VEGFA mRNA levels and VEGFA transcriptional activity whereas silencing FOXO1 reduced it. Moreover, FOXO1 interacted directly with the VEGFA promoter and a deacetylated FOXO1 mutant enhanced VEGFA expression whereas an acetylated FOXO1 mutant did not. Lastly, FOXO1 knockdown by siRNA significantly reduced the capacity of chondrocytes to stimulate microvascular endothelial cell tube formation in vitro. The results indicate that chondrocytes play a key role in angiogenesis which is FOXO1 dependent and that FOXO1 in chondrocytes regulates a potent angiogenic factor, VEGFA. These studies provide new insight into fracture healing given the important role of vessel formation in the fracture repair process. © 2018 American Society for Bone and Mineral Research., (© 2018 American Society for Bone and Mineral Research.)

Purpose: We sought to characterize the angiofibrotic and apoptotic effects of vascular endothelial growth factor (VEGF)-inhibition on fibrovascular epiretinal membranes in eyes with traction retinal detachment because of proliferative diabetic retinopathy., Methods: Membranes were excised from 20 eyes of 19 patients (10 randomized to intravitreal bevacizumab, 10 controls) at vitrectomy. Membranes were stained with antibodies targeting connective tissue growth factor (CTGF) or VEGF and colabeled with antibodies directed against endothelial cells (CD31), myofibroblasts, or retinal pigment epithelium markers. Quantitative and colocalization analyses of antibody labeling were obtained through immunofluorescence confocal microscopy. Masson trichrome staining, cell counting of hematoxylin and eosin sections, and terminal dUTP nick-end labeling staining were performed., Results: High levels of fibrosis were observed in both groups. Cell apoptosis was higher (P = 0.05) in bevacizumab-treated membranes compared with controls. The bevacizumab group had a nonsignificant reduction in colocalization in CD31-CTGF and cytokeratin-VEGF studies compared with controls. Vascular endothelial growth factor in extracted membranes was positively correlated with vitreous levels of VEGF; CTGF in extracted membranes was negatively correlated with vitreous levels of CTGF., Conclusion: Bevacizumab suppresses vitreous VEGF levels, but does not significantly alter VEGF or CTGF in diabetic membranes that may be explained by high baseline levels of fibrosis. Bevacizumab may cause apoptosis within fibrovascular membranes.

Background and Aims: Osteosarcoma is one of the most pernicious primary bone tumor characterized by high malignancy and metastasis, however its pathogenesis remain largely unknown. Our previous study showed elevated expression of adrenomedullin (ADM) is correlated with prognosis and disease severity in osteosarcoma patients. In this research, we continue to study the mechanisms of ADM-induced osteosarcoma cells proliferation in vitro and in vivo osteosarcoma models., Methods: The Radioimmunoassay was used to test the correlations of ADM and vascular endothelial growth factor (VEGF) expressions in plasma of osteosarcoma patients. The MTT and flow cytometry analysis were accepted to monitor the proliferation of osteosarcoma cells, meanwhile the ADM and VEGF expression were detected by real-time PCR and western blot. Moreover, the relationship among ADM and VEGF expression was also assessed in the osteosarcoma nude mice models., Results: In this study, a significant correlation was found between ADM and VEGF expression in the plasma of osteosarcoma patients. As important stimuli in osteosarcoma proliferation, hypoxia could stimulate ADM and VEGF expression in MG-63 cells. The expressions of ADM and VEGF increased with the duration of hypoxia, which also identify the positive correlations between the expression of ADM and VEGF. The proliferation of MG-63 cells decreased when ADM was inhibited. And the proliferation increased when adding exogenous ADM, while VEGF inhibition attenuated this effect. Furthermore, ADM reduction also inhibited VEGF, CD31 expression and tumor cells growth in osteosarcoma nude mice models., Conclusion: These results suggested inhibition of osteosarcoma cells proliferation might be influenced by ADM through VEGF pathway, which implied ADM-VEGF signal was a potential target for impeding the proliferation of malignant cells in osteosarcoma., (Copyright © 2019 IMSS. Published by Elsevier Inc. All rights reserved.)

Angiogenic effects of epidermal growth factor (EGF), a potent mitogen, have been demonstrated previously. Moreover, different in vitro studies showed that EGF affects processes associated with bone healing, such as osteoblast differentiation and bone resorption. The aim of this study was to investigate the effect of combined core decompression (CD) and recombinant human EGF (rhEGF) treatment on early-stage osteonecrosis of the femoral head (ONFH) surgically induced in rats. ONFH was induced by dissecting the cervical periosteum and placing a ligature tightly around the femoral neck. Thirty rats were assigned to one of the following groups (n = 10 each group): sham-operated control, CD, and CD+rhEGF group. rhEGF was injected intraosseously into infarcted areas 2 weeks after the surgery. Preservation of femoral head architecture was assessed at 8 weeks post treatment by radiographic and histomorphological analyses. Osteopontin (OPN) and cluster of differentiation 31 (CD31) were detected by immunochemistry, as indicators of bone remodeling and vascular density, respectively. Inter- and intra-group (non-operated left and operated right femur) differences in radiographic and histomorphological results were analyzed. The femoral head area and sphericity were more preserved in CD+rhEGF compared to CD and sham-control group. CD31 levels were significantly different between the three groups, and were higher in CD+rhEGF compared to CD group. OPN levels were increased in CD and CD+rhEGF groups compared to sham control, but with no significant difference between CD and CD+rhEGF groups. Overall, our results indicate that EGF promotes bone formation and microvascularization in ONFH and thus positively affects the preservation of femoral head during healing.

Cardiac myxomas are rare tumors with a heterogeneous cell population including properly neoplastic (lepidic), endothelial and smooth muscle cells. The assessment of neoplastic (lepidic) cell differentiation pattern is rather difficult using conventional light microscopy immunohistochemistry and/or whole tissue extracts for mRNA analyses. In a preliminary study, we investigated 20 formalin-fixed and paraffin-embedded cardiac myxomas by means of conventional immunohistochemistry; in 10/20 cases, cell differentiation was also analyzed by real-time RT-PCR after laser capture microdissection of the neoplastic cells, whereas calretinin and endothelial antigen CD31 immunoreactivity was localized in 4/10 cases by double immunofluorescence confocal microscopy. Gene expression analyses of α-smooth muscle actin, endothelial CD31 antigen, alpha-cardiac actin, matrix metalloprotease-2 (MMP2) and tissue inhibitor of matrix metalloprotease-1 (TIMP1) was performed on cDNA obtained from either microdissected neoplastic cells or whole tumor sections. We found very little or absent CD31 and α-Smooth Muscle Actin expression in the microdissected cells as compared to the whole tumors, whereas TIMP1 and MMP2 genes were highly expressed in both ones, greater levels being found in patients with embolic phenomena. α-Cardiac Actin was not detected. Confocal microscopy disclosed two different signals corresponding to calretinin-positive myxoma cells and to endothelial CD31-positive cells, respectively. In conclusion, the neoplastic (lepidic) cells showed a distinct gene expression pattern and no consistent overlapping with endothelial and smooth muscle cells or cardiac myocytes; the expression of TIMP1 and MMP2 might be related to clinical presentation; larger series studies using also systematic transcriptome analysis might be useful to confirm the present results.

Inhibitory cell surface proteins on T cells are often dynamically regulated, which contributes to their physiologic function. PECAM-1 (CD31) is an inhibitory receptor that facilitates TGF-β-mediated suppression of T cell activity. It is well established in CD4 + T cells that PECAM-1 is expressed in naïve recent thymic emigrants, but is down-regulated after acute T cell activation and absent from memory cells. The extent to which PECAM-1 expression is similarly regulated in CD8 + T cells is much less well characterized. We evaluated T cells recovered from mice after infection with a model intracellular pathogen and determined that, in CD8 + T cells, PECAM-1 expression was strongly down-regulated during acute infection but re-expressed to intermediate levels in memory cells. Down-regulation of PECAM-1 expression in CD8 + T cells was transcriptionally regulated and affected by the strength and nature of TCR signaling. PECAM-1 was also detected on the surface of human activated/memory CD8 + , but not CD4 + T cells. These data demonstrate that PECAM-1 expression is dynamically regulated, albeit differently, in both CD4 + and CD8 + T cells. Furthermore, unlike memory CD4 + T cells, memory CD8 + T cells retain PECAM-1 expression and have the potential to be modulated by this inhibitory receptor., (©2018 Society for Leukocyte Biology.)

Background: Microvessel density is an indicator of tumor-driven neoangiogenesis. Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) have distinct vascular patterns, which are also reflected in their imaging characteristics. Since a significant proportion of HCC are treated without biopsy confirmation, it is essential to discriminate HCC and ICC radiologically. The aim of our study was therefore to compare microvessel density and expression of VEGFR-2 in HCC and ICC, since these data may ultimately help us to better understand their imaging characteristics. Whereas CD31 documents vessel density, VEGFR-2 expression is an indicator of tumor-related neoangiogenesis., Methods: CD31 and VEGFR-2 expressing microvessels were quantified on tissue microarrays of 95 resection specimens of HCC and 47 cases of ICC. Microvessel density was evaluated by counting immuno-reactive vascular structures both within the tumor and adjacent liver control tissue, respectively. Further 16 cases of ICC were immunostained for CD31 and VEGFR-2 on full sections., Results: The frequency of VEGFR-2 (46.2/HPF; range 0-150) and CD31 (61.2/HPF; range 2.6-140) expressing vascular structures was significantly increased in HCC compared to adjacent liver parenchyma (VEGFR-2 33.3/HPF, range 0-87, CD31 21.4/HPF, range 0-78, both p < 0,001). ICC revealed significantly less VEGFR2-positive microvessels (15.4/HPF; range 2-77) compared to matched control tissue (42.3/HPF; range 4.6-109), whereas microvessel density with CD31 was comparable between ICC and adjacent liver (32.1/HPF; range 5.3-78 versus 28.0/HPF; range 5.3-57; p = 0.89). In ICC, the tumor-to-normal microvessel density ratio was 0.38 for VEGFR-2 and 1.24 for CD31. These ratios were nearly identical (VEGFR: 0.38; CD31: 0,97) for the 16 cases of ICC studied on whole sections, confirming the validity of the TMA approach. In contrast, ratios of VEGFR-2 and CD31 in HCC vs. adjacent liver were significantly higher (VEGFR: 2.23; CD31: 6.57). Expression of VEGFR-2 by tumor cells was not observed in any of the cases., Conclusions: HCC and ICC differ significantly in their microvessel density, confirming the hypovascular nature of ICC as compared to the hypervascularity of HCC. Of note, inverse tumor-to-normal ratios of microvascular VEGFR-2 expression between the two neoplasms indicate distinct features of neoangiogenesis. Whether these differences can be exploited for improvements in imaging of hepatic tumors and may play a role for anti-angiogenic treatment strategies requires further studies., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

Endothelial cells (ECs) are a key component of the blood-brain barrier (BBB). Healthy ECs in the BBB form inter-endothelial junctions, including adherens junctions (AJs). Under pathological conditions, such as after ischemic stroke, the BBB may be functionally compromised. However, gene and protein expression patterns involving endothelial AJs have not been well studied. Because expression levels of endothelial AJs are considered to be related to BBB functionality, we investigated the expression pattern of a representative endothelial AJ marker, VE-cadherin, in healthy and diseased mice. We first examined the expression of VE-cadherin in developing mouse brains. In addition, to a mouse model of cerebral infarction, we investigated the expression pattern of VE-cadherin in pathologic brains. Furthermore, using the Cre-LoxP system, we established a strain of mice expressing yellow fluorescent protein (YFP) under the control of the VE-cadherin promoter and investigated the expression pattern of YFP-expressing ECs in developing and pathologic murine brains. VE-cadherin protein and YFP expression driven by the VE-cadherin promoter both showed that VE-cadherin expression was weak during embryonic stages, followed by a steady increase postnatally, which then decreased during adulthood. However, following ischemic stroke, imunohistochemistry of VE-cadherin demonstrated an upregulation in ECs within ischemic regions, concomitant with YFP upregulation. These findings reveal that ischemic stroke activates the VE-cadherin promoter and increases VE-cadherin protein expression, which suggests that endothelial VE-cadherin is involved in the reconstruction of the BBB following ischemic stroke.

Background/aim: We investigated the expression of angiogenesis and hypoxia markers in the adenohypophysis and neurohypophysis of patients who died from various acute or chronic diseases., Materials and Methods: Paraffin-embedded material of pituitary glands (97 patients) was investigated immunohistochemically for vascular density (CD31) and the expression of vascular endothelial growth factor (VEGF) and of hypoxia inducible factors HIF1α and HIF2α., Results: Vascular density, and HIF1α/HIF2α reactivity is directly related with VEGF expression in the pituitary gland, suggesting that the HIF pathway may regulate the vascular density and blood flow in the gland under hypoxic conditions. HIF2α appears to be a key regulator in neurohypophysis, whilst in adenohypophysis HIF1α and HIF2α are equally expressed. Chronic conditions, including alcoholism and substance abuse, seem to activate the HIF pathway in both neuro- and adeno-hypophysis., Conclusion: The HIF pathway has an important role in regulating vascular density and blood flow in the pituitary gland., (Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Hypoxia-inducible factor-1 alpha (HIF1A) is an important transcription factor for angiogenesis. Recent studies have used the protein transduction domain (PTD) to deliver genes, but the PTD has not been used to induce the expression of HIF1A. This study aimed at using a novel PTD (Hph-1-GAL4; ARVRRRGPRR) to overexpress the HIF1A and identify the effects on angiogenesis in vitro and in vivo. Overexpression of HIF1A was induced using Hph-1-GAL4 in human umbilical vein/vascular endothelium cells (HUVEC). The expression levels of genes were analyzed by the quantitative real-time polymerase chain reaction (qPCR) after 2 and 4 days, respectively. An in vitro tube formation was performed using Diff-Quik staining. HIF1A and Hph-1-GAL4 were injected subcutaneously into the ventral area of each 5-week-old mouse. All of the plugs were retrieved after 1 week, and the gene expression levels were evaluated by qPCR. Each Matrigel plug was evaluated using the hemoglobin assay and hematoxylin and eosin (HE) staining. The expression levels of HIF1A and HIF1A target genes were significantly higher in HIF1A-transfected HUVEC than in control HUVEC in vitro. In the in vivo Matrigel plug assay, the amount of hemoglobin was significantly higher in the HIF1A-treatment group than in the PBS-treatment group. Blood vessels were identified in the HIF1A-treatment group. The expression levels of HIF1A, vascular endothelial growth factor (Vegf), and Cd31 were significantly higher in the HIF1A-treatment group than in the PBS-treatment group. These findings suggest that using Hph-1-G4D to overexpress HIF1A might be useful for transferring genes and regenerating tissues.

Rising evidence points to endothelial-to-mesenchymal transition (EndMT) as a significant source of the mesenchymal cell population in fibrotic diseases. In this context, we hypothesized that liver endothelial cells undergo EndMT during fibrosis progression. Cirrhosis in mice was induced by CCl 4 A transgenic mouse expressing a red fluorescent protein reporter under the control of Tie2 promoter (Tie2-tdTomato) was used to trace the acquisition of EndMT. Sinusoidal vascular connectivity was evaluated by intravital microscopy and high-resolution three-dimensional confocal microscopy. A modest but significant fraction of liver endothelial cells from both cirrhotic patients and CCl 4 -treated Tie2-tdTomato mice acquired an EndMT phenotype characterized by the coexpression of CD31 and α-smooth muscle actin, compared with noncirrhotic livers. Bone morphogenetic protein-7 (BMP-7) inhibited the acquisition of EndMT induced by transforming growth factor-β1 (TGF-β1) treatment in cultured primary mouse liver endothelial cells from control mice. EndMT was also reduced significantly in vivo in cirrhotic Tie2-tdTomato mice treated intraperitoneally with BMP-7 compared with untreated mice (1.9 ± 0.2 vs. 3.8 ± 0.3%, respectively; P < 0.05). The decrease of EndMT in cirrhotic livers correlated with a significant decrease in liver fibrosis ( P < 0.05) and an improvement in the vascular disorganization rate ( P < 0.05). We demonstrated the acquisition of the EndMT phenotype by a subpopulation of endothelial cells from cirrhotic livers in both animal models and patients. BMP-7 treatment decreases the occurrence of the EndMT phenotype and has a positive impact on the severity of disease by reducing fibrosis and sinusoidal vascular disorganization. NEW & NOTEWORTHY A subpopulation of liver endothelial cells from cirrhotic patients and mice with liver fibrosis undergoes endothelial-to-mesenchymal transition. Liver endothelial cells from healthy mice could transition into a mesenchymal phenotype in culture in response to TGF-β1 treatment. Fibrotic livers treated chronically with BMP-7 showed lower EndMT acquisition, reduced fibrosis, and improved vascular organization., (Copyright © 2017 the American Physiological Society.)

In small intestinal submucosa (SIS) scaffolds for functional tissue engineering, the impact of scaffold fabrication parameters on cellular response and tissue regeneration may relate to the mechanotransductory properties of the final arrangement of collagen fibres. We previously proved that two fabrication parameters, (a) preservation (P) or removal (R) of a dense collagen layer present in SIS, and (b) SIS in a final dehydrated (D) or hydrated (H) state, have an effect on the micromechanical environment of SIS. In a continuation of our studies, we herein hypothesized that these fabrication parameters also modulate early mechanotransduction in cells populating the scaffold. Mechanotransduction was investigated by seeding human umbilical vein endothelial cells (HUVECs) on scaffolds, exposing them to pulsatile shear stress (12 ± 4 dyne/cm 2 ) for 1 h (n = 5) in a cone-and-plate shear system, and evaluating the expression of the mechanosensitive genes Pecam1 and Enos by immunofluorescence and qPCR. Expression of mechanosensitive genes was highest in PD grafts, followed by PH and RH grafts. The RD group had similar expression to that of unsheared control cells, suggesting that the RD combination potentially reduced mechanotransduction of shear to cells. We concluded that the two fabrication parameters studied, which modify SIS micromechanics, also potentially modulated the early shear-induced expression of mechanosensitive genes in seeded HUVECs. Our findings suggest that fabrication parameters influence the outcome of SIS as a therapeutic scaffold. Copyright © 2015 John Wiley & Sons, Ltd., (Copyright © 2015 John Wiley & Sons, Ltd.)

Heat shock-related 70-kDa protein 2 (HSPA2) is known to correlate with tumor development and progression. This work aimed to determine the expression and prognostic roles of HSPA2 in pancreatic carcinoma. Tumor and their corresponding non-tumor tissues were obtained from 80 patients with pancreatic carcinoma. HSPA2 expression in tumor and non-tumor tissues was evaluated by immunohistochemistry. Expression of vascular endothelial growth factor (VEGF) and CD31 in tumor tissues were also evaluated by immunostaining. The relationships of HSPA2 with clinicopathological data, tumor angiogenesis and prognosis were analyzed. The results showed that HSPA2 expression was significantly elevated in tumor tissues compared with adjacent non-tumor tissues (P < 0.05). High HSPA2 expression was significantly associated with aggressive clinicopathological characteristics. HSPA2 staining was positively correlated with VEGF (r = 0.466, P < 0.001) and microvessel density (MVD) (r = 0.366, P = 0.001) in tumor tissues. Patients with high HSPA2 expression showed worse relapse-free survival (RFS) (P < 0.001) and overall survival (OS) (P < 0.001) than those with low HSPA2 expression. Multivariate analysis indicated that high HSPA2 expression was an independent predictor for poor RFS (P < 0.001) and OS (P = 0.001). Taken together, overexpressed HSPA2 is correlated with tumor angiogenesis and poor prognosis in pancreatic carcinoma. HSPA2 may play an important role in tumor progression, and serve as a potential biomarker for the prediction of adverse prognosis in pancreatic carcinoma., (Copyright © 2017 IAP and EPC. Published by Elsevier B.V. All rights reserved.)

Esophageal squamous cell carcinoma (ESCC) is the second common cancer in Henan province and is well-known for aggressiveness and dismal prognosis. Adjuvant therapies, chemotherapy, radiotherapy and endoscopic treatment have not improved survival rates in patients with late stage esophageal carcinoma. All-trans retinoic acid (ATRA) is the active ingredient of Vitamin A and affects a wide spectrum of biological processes including development, growth, neural function, immune function, reproduction, and vision. It is one of the most potent therapeutic agents used for treating cancers, especially lung adenocarcinomas. ATRA inhibits metastatic potential and angiogenesis in several tumor models. We investigated the effects of ATRA on the expression of angiopoietin 1 (Ang-1), angiopoietin 2 (Ang-2) and receptor Tie-2 in EC1 cells in vitro. We also assessed the growth and migration of EC1 cells in vitro. ATRA treatment caused 29.5% and 40.3% reduction of the growth of EC1 cells after 24 hours and 48 hours, relative to the control. ATRA plus fluorouracil treatment reduced the viability more strongly than either drug alone, indicating an additive effect. Moreover, ATRA decreased EC1 migration by 87%. Furthermore, ATRA treatment led to a marked decrease of the transcript levels of Ang-1, Ang-2, Tie-2, VEGF, and VEGF receptors, as assessed by real-time RT-PCR. Importantly, the protein levels of Ang-1, Ang-2 and Tie-2 were reduced by ATRA treatment. In vivo, we found ATRA treatment suppressed the tumor growth and improved the cachexia of mice. Importantly, ATRA treatment decreased the expression of CD31, Ang-1, Ang-2 and Tie-2 in subcutaneous tumors of EC1 cells. Collectively, our findings demonstrate that ATRA exhibits a dose- and temporal-dependent effect on the metastatic behavior, suppresses the angiopoietin-Tie2 pathway and inhibits angiogenesis and the progression of xenograft tumors of EC1 cells.

Lung cancer, especially the non-small-cell lung cancer, is a highly aggressive vascular cancer with excessively activated signaling pathways. Tumor-associated calcium signal transducer 2, also known as trop2, was identified to be correlated with tumor proliferation and invasion of non-small-cell lung cancer; however, the biological role of trop2 in neovascularization of non-small-cell lung cancer remained elusive. In this study, we first verified that trop2 was overexpressed in non-small-cell lung cancer tissues as well as cell lines and that the increased expression of trop2 promoted non-small-cell lung cancer cell proliferation and invasion. Then, we expanded the biological role of trop2 by in vitro and in vivo angiogenesis assay. The tubular formation analysis revealed that trop2 promoted non-small-cell lung cancer angiogenesis in vitro, and the immunohistochemistry staining of vascular markers (CD31 and CD34) provided evidences that trop2 promoted in vivo neovascularization. The results of polymerase chain reaction array revealed that trop2 promoted the expression level of two well-known angiogenesis factors MMP13 and PECAM1. By screening the trop2-related signaling pathways, we observed that excessive angiogenesis was correlated with activation of ERK1/2 signaling pathway, and ERK1/2 inhibitor (U0126) could suppress the tubular formation ability induced by trop2 expression. These results suggested that trop2 facilitated neovascularization of non-small-cell lung cancer via activating ERK1/2 signaling pathway. Targeting trop2 might provide novel anti-angiogenesis strategy for non-small-cell lung cancer treatment.

The neuropeptide Calcitonin Gene-Related Peptide (CGRP) is a well-characterized neurotransmitter. However, little is known about the role of CGRP in osteogenesis and vascular genesis during the developmental formation of bone. In the present study, we assessed the abundance of CGRP mRNA and the mRNA of osteogenesis and vascular genesis markers in the foetal mouse mandible and leg bone (tibia). We also analysed the expression and localization of CGRP, osteopontin (OPN) and vascular endothelial growth factor (VEGF-A) using in situ hybridization and immunohistochemical localization in the mouse mandible and tibia at embryonic days 12.5 (E12.5), E14.5, E17.5, and postnatal day 1 (P1). CGRP was clearly detected in the mandible relative to the tibia at E14.5. Hybridization using an anti-sense probe for CGRP was not detected in the mandible at P1. Hybridization with an anti-sense probe for OPN was detected at E14.5, later in the mandible and at P1 in Meckel's cartilage. However, OPN was only detected in the tibia at E17.5 and later. The abundance of CGRP mRNA differed between the mandible and tibia. The level of vasculogenesis markers, such as VEGF-A, was similar to that of CGRP in the mandible. The levels of VEGF-A, cluster of differentiation 31 (CD31) and lymphatic vessel endothelial hyaluronan receptor 1 (LIVE-1) differed from that of OPN in the mandible. In contrast, the levels of VEGF-A, CD31, matrix metalloproteinase-2 (MMP-2), collagen I (Col I), collagen II (Col II) and OPN mRNA differed from E12.5 to P1 (P&lt;0.001) in the tibia. The abundance of mRNA of CGRP and bone matrix markers (Col I, Col II, and OPN) was low at P5 in the tibia. These differences in CGRP and other mRNAs may induce a different manner of ossification between the mandible and tibia. Therefore, a time lag of ossification occurs between the mandible and tibia during foetal development.

The embryonic-maternal interface of the placental labyrinth, allantois, and yolk sac are vital during embryogenesis; however, the precise mechanism underlying the vascularization of these structures remains unknown. Herein we focus on the role of inositol 1,4,5-trisphosphate (IP3) receptors (IP3R), which are intracellular Ca(2+) release channels, in placentation. Double knockout (DKO) of type 1 and 3 IP3Rs (IP3R1 and IP3R3, respectively) in mice resulted in embryonic lethality around embryonic day (E) 11.5. Because IP3R1 and IP3R3 were co-expressed in endothelial cells in the labyrinth, allantois, and yolk sac, we investigated extra-embryonic vascular development in IP3R1- and IP3R3-DKO mice. The formation of chorionic plates and yolk sac vessels seemed dysregulated around the timing of the chorio-allantoic attachment, immediately followed by the disorganization of allantoic vessels, the decreased expression of the spongiotrophoblast cell marker Tpbpa and the growth retardation of the embryos in DKO mice. Fluorescent immunohistochemistry demonstrated downregulation of a vascular endothelial marker, CD31, in labyrinth embryonic vessels and poor elongation of extra-embryonic mesoderm into the labyrinth layer in DKO placenta, whereas the branching of the DKO chorionic trophoblast was initiated. In addition, allantoic and yolk sac vessels in extra-embryonic tissues were less remodeled in DKO mice. In vitro endothelial cord formation and migration activities of cultured vascular endothelial cells derived from human umbilical vein were downregulated under the inhibition of IP3R. Our results suggest that IP3R1 and IP3R3 are required for extra-embryonic vascularization in the placenta, allantois, and yolk sac. This is the first demonstration of the essential role of IP3/IP3Rs signaling in the development of the vasculature at the embryonic-maternal interface., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Purpose: We investigate the antiangiogenic efficacy of tissue plasminogen activator (tPA) on experimental laser-induced choroidal neovascularization (CNV) in mice., Methods: After CNV was induced by laser photocoagulation in 92 C57BL/6J wild-type mice, tPA (4 or 40 international units [IU]/μl) or PBS was injected intravitreally immediately after laser injury. Fluorescein angiography was performed on day 7 to grade CNV leakage. The CNV volume was measured by confocal microscopy in eyes enucleated 7 days after laser injury. Immunohistochemical studies were performed 3 days after laser injury to evaluate fibrin/fibrinogen and CD31 expression. The possible adverse effects of tPA were assessed by electroretinography (ERG) and histology on day 7., Results: Intravitreal administration of tPA significantly suppressed CNV leakage and CNV volume in a dose-dependent manner (P < 0.01). Intravitreal injection of tPA suppressed fibrin/fibrinogen and CD31 expression in laser-induced lesions. Histologic examination and ERG showed no evidence of retinal toxicity in eyes injected with tPA., Conclusions: Intravitreal injection of tPA suppressed fibrin/fibrinogen expression and laser-induced CNV. The current results suggested that tPA may be a potential therapeutic adjuvant for treating CNV.

The present study investigated the effects of combination of ischemic preconditioning (Ipre) and adipose-derived mesenchymal stem cells (ADMSCs) on renal ischemia-reperfusion (I-R) injury in rats. 90 male Sprague Dawley rats were divided into 5 equal groups; sham operated, control (45 min left renal ischemia), Ipre group as control group with 3 cycles of Ipre just before renal ischemia, ADMSCs-treated group (as control with ADMSCs 10(6) cells in 0.1 mL via penile vein 60 min before ischemia time), and Ipre + ADMSCs group as ADMCs group with 3 cycles of Ipre. Ipre and ADMSCs groups showed significant decrease in serum creatinine and blood urea nitrogen (BUN) and caspase-3 and CD45 expression in kidney and significant increase in HIF-1α, SDF-1α, CD31, and Ki67 expressions in kidney compared with the control group (p < 0.05). Moreover, the Ipre + ADMSCs group showed significant decrease in serum BUN and caspase-3 and CD45 expression in kidney with significant increase in HIF-1α, SDF-1α, CD31, and Ki67 expression in kidney compared with the Ipre and ADMCs groups (p < 0.05). We concluded that Ipre potentiates the renoprotective effect of ADMSCs against renal I/R injury probably by upregulation of HIF-1α, SDF-1α, CD31, and Ki67 and downregulation of caspase-3 and CD45.

To observe whether HMGB1could enhance the paracrine effect of MSCs when the Mesenchymal stem cells (Mesenchymal stem cells, MSCs) are pre-proccessed by High Mobility Group Box-1 (High Mobility Group Box-1, HMGB1). And to observe whether it can further increase the quantity of local angiogenesis in myocardial infarcts on the rat model with acute myocardial infarction, HMGB1 was combined with MSCs transplantation. MSCs in rats were cultivated with adherence and centrifugation method. Receptors of TLR4and RAGE in HMGB1 were tested. The MSCs were interfered by HMGB1 with different concentration gradient respectively, then the expression of VEGF was tested with ELISA method. SD male rats were divided into four groups: the model group, the MSCs transplantation group, the HMGB1 injection group, the HMGB1 injection plus MSCs transplantation group (n = 24), preparing rat model with acute myocardial infarction. The serum VEGF concentration levels were detected on the 3rd day, 7th and 28th day with ELISA method. On the 28th day after post operation the density of angiogenesis in infarction area was detected by immunohistochemal. (1) MSCs owned the expression of TLR4 and RAGE. (2) the secretion of VEGF increased significantly after the intervention of HMGB1 with concentration of 12.5 ng/mL, 25 ng/mL, 50 ng/mL, 100 ng/mL and 200ng/ml on MSCs compared with the control group. While the concentration was 400ng/ml or 800ng/ml, the secretion of VEGF decreased compared with the control group (P < 0.05). (3) detection of the serum VEGF on the 3rd or7th day after post operation was arranged: The results showed that: HMGB1 injection plus MSCs transplantation group > MSCs transplantation group >HMGB1 injection group >model group (P < 0.05). (4) the quantity of CD31 stained angiogenesis in HMGB1 injection plus MSCs transplantation group increased obviously. Combining MSCs transplantation, contributed to new angiogenesis of rats with acute myocardial infarction in myocardial infarction area and its near area in rats with acute myocardial infarction.

Lymphovascular invasion (LVI) is an independent predictor of metastatic lymph node disease in penile carcinoma and is one factor used to guide clinical management. The presence of LVI with and without the use of the endothelial immunohistochemical (IHC) markers, ERG and CD31, was retrospectively assessed in 46 penectomy cases containing invasive penile carcinoma (43 squamous cell carcinoma and 3 non-squamous cell carcinoma). Concordance for the detection of LVI between the original report, upon pathology review, and with the use of IHC was determined and histologic pitfalls were identified. For penile squamous cell carcinoma, LVI was diagnosed in 27.9% of tumors in the original reports, 16.3% upon pathology review, and in 16.3% with use of ERG and CD31. Concordance of LVI identification in the original report compared to IHC was 74.4% while concordance of review compared to IHC was 95.3%. Using IHC data as the reference, false positive LVI diagnoses were more common in the original report than false negatives. Histologic mimickers of LVI including involvement of the penile corpora cavernosum or spongiosum vasculature, seromucinous colonization, and a nested pattern of tumor invasion were identified. We demonstrated that it was not uncommon for LVI in penile carcinoma to be overdiagnosed or underdiagnosed. The use of endothelial IHC markers, such as ERG or CD31, or additional pathology consultation is recommended for penectomy cases in which LVI is difficult to histologically discern.

It has previously been suggested that reactive oxygen species (ROS) are involved in the pathogenesis of chronic inflammatory diseases, which entails the initial activation of pro-inflammatory cytokines to facilitate leukocyte transmigration. The present study investigated whether intracellular superoxide dismutase (SOD) suppressed monocyte endothelial trafficking and transmigration. Human umbilical vein endothelial cells (HUVECs) and THP-1 monocytes were activated by the cytokine tumor necrosis factor-α (TNF-α) in the absence and presence of cell-permeable transactivator of transcription (Tat)-SOD protein. External stimulation with SOD was conducted using endothelial cells and monocytes. Purified cell-permeable Tat-SOD, but not non-targeted SOD, at 1-3 µM was transduced into endothelial cells in a time‑ and dose-dependent manner. Non-toxic Tat-SOD at ≤0.5 µM, but not 1 µM SOD, blocked the monocyte-endothelium interactions by inhibiting the TNF-α-induced stimulation of vascular cell adhesion molecule-1 (VCAM-1) in HUVECs and integrin β1 in THP-1 cells. Endothelial VCAM-1 induction by TNF-α was responsible for superoxide anion production being quenched by N-acetyl-cysteine and Tat-SOD. SOD treatment markedly inhibited superoxide anion production induced by TNF-α, but no inhibition of endothelial transmigration was noted. Tat-SOD prevented transendothelial monocyte migration by firmly localizing occludin-1, platelet/endothelial cell adhesion molecule‑1 (PECAM-1) and vascular endothelial‑cadherin present in paracellular junctions and inhibiting endothelial induction and activation of matrix-degrading membrane type-1 (MT-1) matrix metalloproteinase (MMP), MMP-2 and MMP-9. By contrast, treatment with 1 µM SOD did not have such effects. Furthermore, transduced Tat-SOD hindered nuclear transactivation of nuclear factor-κB (NF-κB), modulating the induction of paracellular junction proteins and matrix‑degrading MMP in TNF-α‑stimulated HUVECs. Transduced Tat-SOD, but not external SOD, impeded cytokine-induced endothelial adhesion and the transmigration of monocytes. Thus, we suggest that transduced Tat-SOD qualifies as an atheroprotective agent against oxidation-driven and inflammation-associated atherosclerosis.

Vascular endothelial growth factor (VEGF) plays fundamental roles in testicular development; however, its function on testicular regeneration remains unknown. The objective of this study was to explore the roles VEGF/VEGFR2 signaling plays in mouse germ cells and in mouse testicular regeneration. VEGF and the VEGFR2 antagonist SU5416 were added to culture medium to evaluate their effects on spermatogonial stem cell line (C18-4 cells) proliferation. Testicular cells obtained from newborn male ICR mice were grafted into the dorsal region of male BALB/c nude mice. VEGF and SU5416 were injected into the graft sites to assess the effects of the VEGF and VEGFR2 signaling pathways on testicular reconstitution. The grafts were analyzed after 8 weeks. We found that VEGF promoted C18-4 proliferation in vitro, indicating its role in germ cell survival. HE staining revealed that seminiferous tubules were reconstituted and male germ cells from spermatogonia to spermatids could be observed in testis-like tissues 8 weeks after grafting. A few advantaged male germ cells, including spermatocytes and spermatids, were found in SU5416-treated grafts. Moreover, VEGF enhanced the expression of genes specific for male germ cells and vascularization in 8-week grafts, whereas SU5416 decreased the expression of these genes. SU5416-treated grafts had a lower expression of MVH and CD31, indicating that blockade of VEGF/VEGFR2 signaling reduces the efficiency of seminiferous tubule reconstitution. Collectively, these data suggest that VEGF/VEGFR2 signaling regulates germ cell proliferation and promotes testicular regeneration via direct action on germ cells and the enhancement of vascularization., (© 2016 S. Karger AG, Basel.)

Aim: to make a comparative histological study of the placenta and a morphometric analysis of its terminal villi in early- and late-onset preeclampsia., Material and Methods: Placentae from patients whose pregnancy had been complicated by the development of early- (n=26) or late-onset (n=84) preeclampsia were examined. A control group comprised placentae from 28 patients with physiological pregnancy and no extragenital diseases. The authors made a comparative histological study of placental tissue and a morphometric analysis of the terminal villi using the sections immunohistochemically stained for CD31., Results: It was determined that there was a preponderance of branching angiogenesis in the preeclamptic chorionic villi and an increase in the number of syncytial nodules and microcysts in the septae in late-onset preeclampsia. Morphometric analysis of immunohistochemical placental specimens established a reduction in the sizes and vascularization indicators of terminal villi that determine the development of placental hypoxia and are more pronounced in cases of early-onset preeclampsia.

Introduction: Immune-mediated angiogenesis may play an important role in the pathogenesis of inflammatory lesions in Crohn's disease (CD). The study aimed to assess the influence of anti-tumour necrosis factor (anti-TNF) therapy on the angiogenesis in relation to microscopic and endoscopic healing in CD patients., Material and Methods: Colonic tissue samples from 17 CD patients were taken during colonoscopy before and after anti-TNF therapy. Endoscopic and microscopic severities were estimated using validated scores. Immunohistochemical expression of CD31 and vascular endothelial growth factor (VEGF) were assessed in parallel., Results: The expression of CD31 and VEGF decreased significantly after the anti-TNF therapy in parallel to endoscopic improvement; however, the microscopic activity did not change significantly. There was a correlation between the change in CD31 and VEGF expression (p = 0.01; r = 0.6), as well as endoscopic healing (p = 0.04; r = 0.4). CD31 immunoexpression correlated with the number of poly- and mononuclear cells in the infiltrates in the mucosal lamina propria before the therapy (p = 0.02; r = 0.5)., Conclusions: We suggest that modulation of vascular proliferation can be a novel option to increase the efficacy of biological therapy in CD.

The importance of vascularization in the field of bone tissue engineering has been established by previous studies. The present work proposes a novel poly(propylene fumarate) (PPF)/fibrin composite scaffold for the development of vascularized neobone tissue. The effect of prevascularization (i.e., in vitro pre-culture prior to implantation) with human mesenchymal stem cells (hMSCs) and human umbilical vein endothelial cells (HUVECs) on in vivo vascularization of scaffolds was determined. Five conditions were studied: no pre-culture (NP), 1 week pre-culture (1P), 2 week pre-culture (2P), 3 week pre-culture (3P), and scaffolds without cells (control, C). Scaffolds were implanted subcutaneously in a severe combined immunodeficiency (SCID) mouse model for 9 days. During in vitro studies, CD31 staining showed a significant increase in vascular network area over 3 weeks of culture. Vascular density was significantly higher in vivo when comparing the NP and 3P groups. Immunohistochemical staining of human CD-31 expression indicated spreading of vascular networks with increasing pre-culture time. These vascular networks were perfused with mouse blood indicated by perfused lectin staining in human CD-31 positive vessels. Our results demonstrate that in vitro prevascularization supports in vivo vascularization in PPF/fibrin scaffolds., Competing Interests: Statement: No Conflicts of Interest to disclose., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Aims Systemic sclerosis (SSc) is characterized by vasculopathy and organ fibrosis. Although microvascular alterations are very well characterized, structural and functional abnormalities of large vessels are not well defined. Therefore, we evaluated the effect of simvastatin administration on aortic and small renal arteries thickening, and on myofibroblasts differentiation in a murine model of SSc. Methods and results SSc was induced in BALB/c mice by daily subcutaneous injections of hypochlorous acid (HOCl, 100 μl) for 6 weeks. Mice (n = 23) were randomized to receive: HOCl (n = 10); HOCl plus simvastatin (40 mg/kg; n = 8); or vehicle (n = 5). Simvastatin administration started 30 min after HOCl injection, and up to week 6. Aortic and small renal arteries intima-media thickness was evaluated by histological analysis. Immunostaining for α-smooth muscle actin (SMA), vascular endothelial growth factor receptor 2 (VEGFR2), and CD31 in aortic tissues was performed to evaluate myofibroblast differentiation and endothelial markers.In HOCl-treated mice, intima-media thickening with reduced lumen diameter was observed in the aorta and in small renal arteries and simvastatin administration prevented this increase. Aortic and renal myofibroblasts count, as expressed by α-SMA + density, was lower in the group of mice treated with simvastatin compared to HOCl-treated mice. Simvastatin prevented the reduction in VEGFR2 and CD31 expression induced by HOCl. Conclusions The administration of simvastatin regulates collagen deposition in the aortic tissues and in the small renal arteries by modulating myofibroblasts differentiation and vascular markers. Further studies are needed to better address the effect of statins in the macrovascular component of SSc.

Morin, a flavonoid isolated from Morus alba L. (Moraceae), possesses anti-inflammatory, antiangiogenic among other biological activities. This study investigated its effect on type II collagen-induced arthritis (CIA) in rats and explored the underlying mechanisms in view of synovial angiogenesis. Morin administered po attenuated arthritic progression as indicated by reduction of arthritis scores and paw swelling. It also markedly reduced serum levels of the proinflammatory cytokines, tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), but increased the level of anti-inflammatory cytokine interleukin-10, and ameliorated histopathological changes of joints. Morin markedly inhibited expression of CD31, vascular endothelial growth factor (VEGF), and basic fibroblast growth factor in synovial membrane tissues, and decreased serum levels of VEGF in CIA rats. In vitro, morin markedly inhibited VEGF-induced migration and tube formation in human umbilical vein endothelial cells. These results indicate that morin had antirheumatoid potential, and its mechanism might be associated with inhibition of synovial angiogenesis., (© 2015 Wiley Periodicals, Inc.)

Unlabelled: i), Aims: The current study aimed to examine the effect of leflunomide on tumoral expression of epidermal growth factor and its receptor (EGFR) in Ehrlich's ascites carcinoma (EAC) grown in mice. ii), Materials and Methods: Mice were injected subcutaneously with EAC cells and allocated into four groups; Group i: EAC control group. Groups ii-iv: mice treated with leflunomide (3, 10 or 30mg/kg/day, p.o.), respectively. Pharmacologic treatments were initiated at day 8 and continued for 14days. iii), Key Findings: Treatment with leflunomide evoked antitumor properties as indicated by reduction in tumor mass, histopathological score, number of intratumoral PCNA immunopositive nuclei. Leflunomide (3, 10 or 30mg/kg) exerted an anti-inflammatory effect as indicated by the reduction in serum tumor necrosis factor-α. Furthermore, leflunomide demonstrated anti-angiogenic activity which was expressed as a decline in serum vascular endothelial growth factor and down-regulation of intratumoral EGF protein and mRNA expression as well as EGFR expression in addition to suppression of immunostaining for the endothelial marker, CD31. iv), Significance: Taken together, the present results demonstrated that leflunomide possessed anti-angiogenic and anti-proliferative activity against EAC solid tumors that might be correlated to down regulation of EGF and EGFR. Further, the current data indicated that leflunomide may have utility in the management of human cancer., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Unlabelled: Atherosclerosis is a multifactor disease, in which dysfunction of the endothelium leads to the emergence of its adhesion molecules., Objective: to investigate the expression of the endothelial adhesion molecules PECAM (CD31), ICAM, and VCAM, as well as adherent endothelial T cells and monocytes. The material examined was en face pulmonary and coronary artery samples taken during autopsies (10 men), and en face specimens obtained from the coronary artery fragments taken from coronary heart disease patients during endarterectomy (37 men). This investigation used antibodies to the adhesion molecules ICAM-1, VCAM-1, and PECAM and those to CD3, CD4, CD8 T-cells and CD68 monocytes., Results: The endothelial cells in the atherosclerotically intact coronary arteries had an elongated shape and were aligned along the blood flow. Those located above atheromas and fibroatheromas changed their shape from elongated to polygonal. Above the fatty streaks and atheromas, the reaction with antibodies to CD31 antigens became weaker at the edge of endothelial cells and disappeared in places. While the atherosclerotic process progressed, the reaction with the CD31 antigen at the edge of endothelial cells was similar in intensity to that on the surface of the endothelium. Adhesion of T cells and monocytes to the endothelium of coronary arteries increased as the atherosclerotic vascular process progressed. T cells and monocytes more often adhered to the endothelium at the sites where the endothelial cells contacted each other., Conclusion: Heterogeneity was found in the endothelial cells: their shape, the expression of adhesion molecules, and the adhesion of lymphocytes and monocytes to them changed during the progression of the atherosclerotic process.

Cytokines play important roles in cardiac repair and regeneration. Recently, we demonstrated that interleukin (IL)-6 family cytokines induce the endothelial differentiation of Sca-1+ cardiac resident stem cells through STAT3/Pim-1 signaling pathway. In contrast, the biological functions of IL-12 family cytokines in heart remain to be elucidated, though they show structural homology with IL-6. In the present study, we examined the effects of IL-12 family cytokines on the transdifferentiation of cardiac Sca-1+ cells into cardiac cells. RT-PCR analyses revealed that IL-27 receptor α (IL-27Rα), but not IL-12R or IL-23R, was expressed in cardiac Sca-1+ cells. The transcript expression of IL-27 was elevated in murine hearts in cardiac injury models. Intriguingly, IL-27 stimulation for 14 days induced the endothelial cell (EC) marker genes, such as CD-31 and VE-cadherin. Immunoblot analyses clarified that IL-27 treatment rapidly phosphorylated STAT3. IL-27 upregulated the expression of Pim-1, but the overexpression of dominant negative STAT3 abrogated the induction of Pim-1 by IL-27. Finally, adenoviral transfection of dominant negative Pim-1 inhibited IL-27-induced EC differentiation of cardiac Sca-1+ cells. These findings demonstrated that IL-27 promoted the commitment of cardiac stem cells into the EC lineage, possibly leading to neovascularization as a novel biological function. IL-27 could not only regulate the inflammation but also contribute to the maintenance of the tissue homeostasis through stem cell differentiation at inflammatory sites., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The deposition of extracellular matrix (ECM) proteins by hepatic cells during fibrosis leads to the stiffening of the organ and perturbed cellular functions. Changes in the elasticity of liver tissue are manifested by altered phenotype in hepatic cells. We have investigated changes in human liver sinusoidal endothelial cells (hLSECs) that occur as the elastic modulus of their matrix transitions from healthy (6kPa) to fibrotic (36kPa) conditions. We have also investigated the role played by Kupffer cells in the dedifferentiation of hLSECs. We report the complete loss of fenestrae and the expression of CD31 at the surface as a result of increasing elastic moduli. LSECs exhibited a greater number of actin stress fibers and vinculin focal adhesion on the stiffer substrate, as well. A novel finding is that these identical trends can be obtained on soft (6kPa) substrates by introducing an inflamed microenvironment through the addition of Kupffer cells. hLSEC monocultures on 6kPa gels exhibited fenestrae that were 140.7±52.6nm in diameter as well as a lack of surface CD31 expression. Co-culturing hLSECs with rat Kupffer cells (rKCs) on 6kPa substrates, resulted in the complete loss of fenestrae, an increase in CD31 expression and in a well-organized cytoskeleton. These results demonstrate that the increasing stiffness of liver matrices does not solely result in changes in hLSEC phenotype. Even on soft substrates, culturing hLSECs in an inflamed microenvironment can result in their dedifferentiation. Our findings demonstrate the interplay between matrix elasticity and inflammation in the progression of hepatic fibrosis., (Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Repeated and dramatic pregnancy-induced uterine enlargement and remodeling throughout reproductive life suggests the existence of uterine smooth muscle stem/progenitor cells. The aim of this study was to isolate and characterize stem/progenitor-like cells from human myometrium through identification of specific surface markers. We here identify CD49f and CD34 as markers to permit selection of the stem/progenitor cell-like population from human myometrium and show that human CD45(-) CD31(-) glycophorin A(-) and CD49f(+) CD34(+) myometrial cells exhibit stem cell-like properties. These include side population phenotypes, an undifferentiated status, high colony-forming ability, multilineage differentiation into smooth muscle cells, osteoblasts, adipocytes, and chondrocytes, and in vivo myometrial tissue reconstitution following xenotransplantation. Furthermore, CD45(-) CD31(-) glycophorin A(-) and CD49f(+) CD34(+) myometrial cells proliferate under hypoxic conditions in vitro and, compared with the untreated nonpregnant myometrium, show greater expansion in the estrogen-treated nonpregnant myometrium and further in the pregnant myometrium in mice upon xenotransplantation. These results suggest that the newly identified myometrial stem/progenitor-like cells influenced by hypoxia and sex steroids may participate in pregnancy-induced uterine enlargement and remodeling, providing novel insights into human myometrial physiology., (© 2015 by the Society for the Study of Reproduction, Inc.)

Although granulocyte-colony stimulating factor (G-CSF) is commonly used to support recovery from radiation-induced side-effects, the precise effects of G-CSF on colon cancer under radiotherapy remain poorly understood. In the present study, to investigate the effects of tumor growth following radiotherapy and G-CSF administration in a murine xenograft model of colon cancer, female BALB/c mice were injected with cells of a colon carcinoma cell line (CT26) with irradiation and G-CSF, alone or in combination. Mice received 2 Gy of focal radiation daily for 5 days and intraperitoneal injection of G-CSF (100 µg/kg/day) after irradiation for 7 days. Changes in the levels of myeloperoxidase (MPO), vascular endothelial growth factor (VEGF), matrix metalloproteinase type 9 (MMP-9) and CD31 were assessed in the mouse cancer induced by injection of colon cancer cells. We observed that G-CSF increased the number of circulating neutrophils, but facilitated tumor growth. However, G-CSF treatment did not affect radiation-induced cytotoxicity and cell viability in CT26 cells in vitro. Increased levels of myeloperoxidase, a neutrophil marker and those of vascular endothelial growth factor were observed in tumors with G-CSF supplementation. In addition, we found that increased levels of CD31 and matrix metalloproteinase-9 were correlated with the enhanced tumor growth after G-CSF treatment. Therefore, these data suggest that G-CSF may contribute to tumor growth and decrease the antitumor effect of radiotherapy, possibly by promoting vascularization in cancer lesions.

In the present study, rat liver acellular scaffolds were used as biological support to guide the differentiation of human liver stem-like cells (HLSC) to hepatocytes. Once recellularized, the scaffolds were maintained for 21 days in different culture conditions to evaluate hepatocyte differentiation. HLSC lost the embryonic markers (alpha-fetoprotein, nestin, nanog, sox2, Musashi1, Oct 3/4, and pax2), increased the expression of albumin, and acquired the expression of lactate dehydrogenase and three subtypes of cytochrome P450. The presence of urea nitrogen in the culture medium confirmed their metabolic activity. In addition, cells attached to tubular remnant matrix structures expressed cytokeratin 19, CD31, and vimentin. The rat extracellular matrix (ECM) provides not only a favorable environment for differentiation of HLSC in functional hepatocytes (hepatocyte like) but also promoted the generation of some epithelial-like and endothelial-like cells. When fibroblast growth factor-epidermal growth factor or HLSC-derived conditioned medium was added to the perfusate, an improvement of survival rate was observed. The conditioned medium from HLSC potentiated also the metabolic activity of hepatocyte-like cells repopulating the acellular liver. In conclusion, HLSC have the potential, in association with the natural ECM, to generate in vitro a functional "humanized liver-like tissue."

Background: Statins have been reported to promote bone formation. However, taken orally, their bioavailability is low to the bones. Implant therapies require a local repair response, topical application of osteoinductive agents, or biomaterials that promote implant fixation., Material/methods: The present study evaluated the effect of a single local injection of simvastatin on screw fixation in an ovariectomized rat model of osteoporosis., Results: Dual-energy X-ray absorptiometry, micro-computed tomography, histology, and biomechanical tests revealed that 5 and 10 mg simvastatin significantly improved bone mineral density by 18.2% and 22.4%, respectively (P<0.05); increased bone volume fraction by 51.0% and 57.9%, trabecular thickness by 16.4% and 18.9%, trabeculae number by 112.0% and 107.1%, and percentage of osseointegration by 115.7% and 126.3%; and decreased trabeculae separation by 34.1% and 36.6%, respectively (all P<0.01). Bone mineral apposition rate was significantly increased (P<0.01). Furthermore, implant fixation was significantly increased (P<0.05), and bone morphogenetic protein 2 (BMP2) expression was markedly increased. Local injection of a single dose of simvastatin also promoted angiogenesis. Vessel number, volume, thickness, surface area, and vascular volume per tissue volume were significantly increased (all P<0.01). Vascular endothelial growth factor (VEGF), VEGF receptor-2, von Willebrand factor, and platelet endothelial cell adhesion molecule-1 expression were enhanced., Conclusions: A single local injection of simvastatin significantly increased bone formation, promoted osseointegration, and enhanced implant fixation in ovariectomized rats. The underlying mechanism appears to involve enhanced BMP2 expression and angiogenesis in the target bone.

Background: Invasive micropapillary carcinoma (IMPC) is a rare variant of colorectal cancer with an adverse prognosis. "Retraction artifact" around tumor cells is a feature of IMPC. The aim of this study was to assess the nature of the retractions around the tumor cells and to describe the histopathological features of a group of 18 cases of IMPC., Methods: A pathology review of 128 consecutive colorectal cancers identified 18 cases of histologically proven IMPC using 5% of the total tumor volume comprised of a micropapillary component as the diagnostic criterion. Immunostains for D2-40, CD31, CD34, vascular endothelial growth factor A (VEGF-A), and mucin 1 (MUC-1) were performed using the avidin-biotin complex method., Results: Cases of IMPC were characterized by pseudomicropapillae surrounded by lacunar-like clear spaces. These structures exhibited the inside-out growth pattern as highlighted by MUC-1 staining. The lining of the lacunar spaces was immunoreactive to CD31 but not CD34 or D2-40, indicating that they are neovascular structures. Furthermore, the tumor cells strongly and diffusely expressed VEGF-A., Conclusions: The strong coexpression of VEGF-A and CD31 suggests a prominent role of neoangiogenesis in these tumors.

Hematogenous metastasis, mainly hepatic metastasis, is a frequent metastatic mode in colorectal cancer involving angiogenic growth factors. Two angiogenic growth factors, in particular, Vascular endothelial growth factor (VEGF) and Prokineticin1(PROK1), are considered to have an important role in hematogenous metastasis of colorectal cancer. Accordingly, we report our findings on the importance of the anti-tumor efffect by inhibiting these two factors in human colorectal cancer.When the culture fluid of Colorectal cancer cell lines(DLD-1, HCT116, and LoVo) with high levels of VEGF/PROK1 expression was injected subcutaneously into mice, the culture fluid increased subcutaneous angiogenesis. But when both anti-PROK1 and anti-VEGF antibodies were present in the culture fluid, the length and size of the blood vessels were reduced compared with those seen in the fluid-only, anti-PROK1, and anti-VEGF controls. Also, tumor masses were produced in mice by subcutaneously embedding colorectal cancer cells with high levels VEGF/PROK1 expression. When both anti-PROK1 and anti-VEGF antibodies were simultaneously applied, tumor formation and peritumoral angiogenesis were strongly suppressed, compared with when either anti-PROK1 antibody or anti-VEGF antibody was applied alone.Simultaneous targeting of both angiogenic growth factors (VEGF/PROK1) may prove more useful in colorectal cancer.

Introduction: The application of isoflurane in a postconditioning manner, during early reperfusion of ischemic myocardium, reduces the infarct size. Its favorable effect on highly vascularized granulation tissue formation is very important considering the fact that increased genesis of blood vessels in peri-infarct zone reduces the infarct size and improves cardiac function. Taking into consideration the influence of isoflurane on the subacute phase of infarct healing, by using different immunohistochemical markers, we wanted to explore whether isoflurane postconditioning influences the chronic phase of healing., Methods: The size of infarcted region was measured, and comparisons between isoflurane-treated and control animals were made. Quality of infarcted area was assessed by detecting vascular endothelial growth factor (VEGF), platelet/endothelial cell adhesion molecule-1 (PECAM-1/CD31) as a marker of angiogenesis, and nestin as a marker of immature progenitor cells, and de novo formed blood vessels (vasculogenesis)., Results: There was no difference between the control and isoflurane-treated groups in VEGF and PECAM-1/CD31 expression. However, a large reduction in infarct size was found (68.1% of control). Also, a marked decrease of nestin expression in immature progenitor cells, along with a marked increase of the same marker in cardiomyocytes, (signs of myocardium regeneration), was found in experimental animals when compared to control animals that did not receive isoflurane treatment., Conclusions: Based on our results, we can emphasize two morphologically detectable benefits of isoflurane postconditioning: a marked reduction in infarct size along with a more mature-looking infarct area in the chronic phase of infarct healing., (Copyright © 2014 Elsevier Inc. All rights reserved.)