Vascular Endothelial Growth Factor Induces Extracellular Matrix Proteins and Osteopontin in the Umbilical Artery

Radiation induces acute and subacute vascular regression in a three-dimensional microvasculature model

Radiation treatment is one of the most frequently used therapies in patients with cancer, employed in approximately half of all patients. However, the use of radiation therapy is limited by acute or chronic adverse effects and the failure to consider the tumor microenvironment. Blood vessels substantially contribute to radiation responses in both normal and tumor tissues. The present study employed a three-dimensional (3D) microvasculature-on-a-chip that mimics physiological blood vessels to determine the effect of radiation on blood vessels. This model represents radiation-induced pathophysiological effects on blood vessels in terms of cellular damage and structural and functional changes. DNA double-strand breaks (DSBs), apoptosis, and cell viability indicate cellular damage. Radiation-induced damage leads to a reduction in vascular structures, such as vascular area, branch length, branch number, junction number, and branch diameter; this phenomenon occurs in the mature vascular network and during neovascularization. Additionally, vasculature regression was demonstrated by staining the basement membrane and microfilaments. Radiation exposure could increase the blockage and permeability of the vascular network, indicating that radiation alters the function of blood vessels. Radiation suppressed blood vessel recovery and induced a loss of angiogenic ability, resulting in a network of irradiated vessels that failed to recover, deteriorating gradually. These findings demonstrate that this model is valuable for assessing radiation-induced vascular dysfunction and acute and chronic effects and can potentially improve radiotherapy efficiency.

Gestational folic acid deficiency alters embryonic eye development: Possible role of basement membrane proteins in eye malformations

OBJECTIVES

Folic acid (FA) is crucial before and during early pregnancy. FA deficiency can occur because dietary FA intake is low in mothers at the time of conception. Likewise, various ocular pathologies are related to the alteration of extracellular matrices. The present study aimed to investigate the association between maternal FA deficiency and congenital eye defects. We also investigated whether maternal diet deficient in FA alters the expression of collagen IV and laminin-1 as a possible mechanism responsible for the appearance of ocular malformations. Both proteins are the main components of the basal lamina, and form an interlaced network that creates a relevant scaffold basement membrane. Basal laminae are involved in tissues maintenance and implicated in regulating many cellular processes.

METHODS

A total of 57 mouse embryos were classified into the following groups: Control group, (mothers were fed a standard rodent diet), and D2 and D8 groups (mothers were fed FA-deficient [FAD] diet for 2 or 8 wk, respectively). Female mice from group D2 were fed a FAD diet (0 mg/kg diet + 1% succinyl sulfathiazole used to block the synthesis of FA) for 2 wk from the day after mating until day 14.5 of gestation (E14.5). On the other hand, female mice from group D8 were fed a FAD diet for 8 wk (6 wk before conception and during the first 2 wk of pregnancy). For the data analysis, we first estimated the incidence of malformations in each group. Then, the statistical analysis was performed using IBM SPSS Statistics, version 25.0. Expression patterns of collagen IV and laminin-1 were examined with the immunohistochemical technique.

RESULTS

Our results showed that mice born to FA-deficient mothers had several congenital eye abnormalities. Embryos from dams fed a short-term FAD diet were found to have many significant abnormalities in both anterior and posterior segments, as well as choroidal vessel abnormalities. However, embryos from dams fed a long-term FAD diet had a significantly higher incidence of eye defects. Finally, maternal FA deficiency increased the expression of both collagen IV and laminin-1. Likewise, changes in the spatial localization and organization of collagen IV were observed.

CONCLUSIONS

A maternal FAD diet for a short-term period causes eye developmental defects and induces overexpression of both collagen IV and laminin-1. The malformations observed are probably related to alterations in the expression of basement membrane proteins.

Platelet activating factor in the eye: Physiological roles, diseases and future perspectives

Platelet Activating Factor (PAF) is a known phospholipid mediator of inflammation. Since its first description in 1972, it has emerged as a key regulator of vital cellular signaling functions, as proliferation, cell adhesion, and apoptosis. Evidence suggests that interactions between PAF and its receptor (PAFR) play a critical role in nervous system tissues, including the retina. The retina is a very important constituent of the visual system, along with the cornea, sclera, choroid, iris, and ciliary body, that acts synergistically to provide vision and to maintain optical homeostasis. There is evidence that PAF may regulate a wide range of physiological functions in the visual system tissues, such as eye development, inflammation, epithelial wound healing, and synapsis. Due to their multiple functions, PAF and PAFR also have important pathological and clinical implications in ocular disorders such as Choroidal Neovascularization (CNV), Age Macular Degeneration, (AMD), Diabetic Retinopathy (DR), transplant responses, and pharmacological interactions. Studies with PAFR antagonists have shown promising results such as inhibition of neovascularization and chloroquine-induced retinopathies, as well as reducing inflammation and retinal cell death. Due to the importance of PAFR signaling in the visual system and ophthalmology research, this review aims to provide a general overview of current and future perspectives about PAF in eye biology.

Endothelial cells support osteogenesis in an in vitro vascularized bone model developed by 3D bioprinting

Bone is a highly vascularized tissue, in which vascularization and mineralization are concurrent processes during skeletal development. Indeed, both components should be included in any reliable and adherent in vitro model platform for the study of bone physiology and pathogenesis of skeletal disorders. To this end, we developed an in vitro vascularized bone model, using a gelatin-nanohydroxyapatite (gel-nHA) three-dimensional (3D) bioprinted scaffold. First, we seeded human mesenchymal stem cells (hMSCs) on the scaffold, which underwent osteogenic differentiation for 2 weeks. Then, we included lentiviral-GFP transfected human umbilical vein endothelial cells (HUVECs) within the 3D bioprinted scaffold macropores to form a capillary-like network during 2 more weeks of culture. We tested three experimental conditions: condition 1, bone constructs with HUVECs cultured in 1:1 osteogenic medium (OM): endothelial medium (EM); condition 2, bone constructs without HUVECs cultured in 1:1 OM:EM; condition 3: bone construct with HUVECs cultured in 1:1 growth medium:EM. All samples resulted in engineered bone matrix. In conditions 1 and 3, HUVECs formed tubular structures within the bone constructs, with the assembly of a complex capillary-like network visible by fluorescence microscopy in the live tissue and histology. CD31 immunostaining confirmed significant vascular lumen formation. Quantitative real-time PCR was used to quantify osteogenic differentiation and endothelial response. Alkaline phosphatase and runt-related transcription factor 2 upregulation confirmed early osteogenic commitment of hMSCs. Even when OM was removed under condition 3, we observed clear osteogenesis, which was notably accompanied by upregulation of osteopontin, vascular endothelial growth factor, and collagen type I. These findings indicate that we have successfully realized a bone model with robust vascularization in just 4 weeks of culture and we highlighted how the inclusion of endothelial cells more realistically supports osteogenesis. The approach reported here resulted in a biologically inspired in vitro model of bone vascularization, simulating de novo morphogenesis of capillary vessels occurring during tissue development.

Dysregulation of inflammatory cytokines and inhibition of VEGFA in the human umbilical cord are associated with negative pregnancy outcomes

INTRODUCTION

Cytokines and vascular endothelial growth factors (VEGF) are involved in all aspects of pregnancy: from placentation, through fetal development, parturition and neonatal well-being. Umbilical cord inflammatory cytokines and/or VEGF have not been well studied with respect to dysregulation associated with disorders of pregnancy or maternal/neonatal outcomes.

METHODS

Here we have used multiplex ELISA to screen umbilical cord lysates (comprising cord blood, endothelia and Wharton's jelly, n = 380), for levels of IFN-γ, IL1-β, IL-6, IL-8, IL-10, TNF-α and VEGFs A, C and D and associations with 46 ICD9/10 codes encompassing obstetric, maternal and neonatal variables.

RESULTS

No significant differences were observed for IFNγ, VEGFC or VEGFD with any clinical outcomes. The cytokines IL1-β, IL-6, IL-8, IL-10, and TNF-α showed varying levels of induction and suppression with primarily fetal-placental and neonatal complications. The largest number of significant differences between umbilical cytokines and clinical outcomes were observed for chorioamnionitis (IL1-β, IL-6, IL-8, TNF-α), and meconium passage during birth (IL1-β, IL-6, IL-8) where significant pro-inflammatory responses occurred and sex differences in IL-8 expression were noted. In contrast, gonococcal infection showed suppressed immune response significantly lowering IL1-β, IL-6, IL-8, IL-10 and TNF-α. For 12/46 negative pregnancy outcomes, strong suppression of VEGFA occurred.

DISCUSSION

Angiogenic and inflammatory changes in the umbilical cord could be detrimental by increasing vascular permeability in the umbilical artery or vein and/or altering vascular tone, either of which would alter blood flow affecting delivery and removal of compounds. Further elucidation of inflammatory responses in the umbilical cord may provide mechanistic understanding of adverse pregnancy outcomes.

Morphological and Molecular Changes in Juvenile Normal Human Fibroblasts Exposed to Simulated Microgravity

The literature suggests morphological alterations and molecular biological changes within the cellular milieu of human cells, exposed to microgravity (µg), as many cell types assemble to multicellular spheroids (MCS). In this study we investigated juvenile normal human dermal fibroblasts (NHDF) grown in simulated µg (s-µg) on a random positioning machine (RPM), aiming to study changes in cell morphology, cytoskeleton, extracellular matrix (ECM), focal adhesion and growth factors. On the RPM, NHDF formed an adherent monolayer and compact MCS. For the two cell populations we found a differential regulation of fibronectin, laminin, collagen-IV, aggrecan, osteopontin, TIMP-1, integrin-β₁, caveolin-1, E-cadherin, talin-1, vimentin, α-SM actin, TGF-β₁, IL-8, MCP-1, MMP-1, and MMP-14 both on the transcriptional and/or translational level. Immunofluorescence staining revealed only slight structural changes in cytoskeletal components. Flow cytometry showed various membrane-bound proteins with considerable variations. In silico analyses of the regulated proteins revealed an interaction network, contributing to MCS growth via signals mediated by integrin-β₁, E-cadherin, caveolin-1 and talin-1. In conclusion, s-µg-conditions induced changes in the cytoskeleton, ECM, focal adhesion and growth behavior of NHDF and we identified for the first time factors involved in fibroblast 3D-assembly. This new knowledge might be of importance in tissue engineering, wound healing and cancer metastasis.

Osteopontin b and c Splice isoforms in Leukemias and Solid Tumors: Angiogenesis Alongside Chemoresistance

Osteopontin (OPN) is a glycoprotein involved in regulation of various influences on tumor progression, such as cellular proliferation, apoptosis, angiogenesis, and metastasis. Vascular endothelial growth factor (VEGF) is a secreted molecule supporting angiogenesis in various cancers through activation of the PI3K/AKT/ERK1/2 pathway. OPN and VEGF have a number of isoforms with various activities. In spite of the well-defined association between OPN and VEGF isoform expression and cure rate for solid tumors, there is a scarcity of information as to any association in leukemia. Based on the critical role of OPN in cell survival, it seems reasonable to hypothesize that OPN and VEGF isoform expression levels may impact on chemoresistance and relapse in leukemia the same as in solid tumors. Hence, the aim of our review was to explain relationships between OPN and VEGF isoforms and angiogenesis and related pathways in chemoresistance of leukemia and solid tumors. Our findings demonstrated that OPNb and OPNc alongside with VEGF isoforms and other gene pathways are involved in angiogenesis and also might promote chemoresistance and even recurrence in leukemia and solid tumors. To sum up, targeting OPN isoforms, particularly b and c, might be a novel therapeutic strategy for the treatment of leukemia as well as solid tumors.

Relationship of Cx43 regulation of vascular permeability to osteopontin-tight junction protein pathway after sepsis in rats

Our previous study demonstrated that connexin (Cx)43 participated in the regulation of vascular permeability in severe sepsis. Osteopontin (OPN) has been demonstrated to participate in the occurrence of atherosclerosis, inflammation, as well as the adhesion and migration of cells. It is not clear whether OPN is involved in Cx43 regulating vascular permeability after sepsis and if it is related to tight-junction proteins. with the use of cecal ligation and puncture (CLP)-induced septic rats and lipopolysaccharide (LPS)-treated pulmonary vein vascular endothelial cells (VECs), the role of zona occuldens 1 (ZO-1) and claudin-5 in Cx43 regulation of vascular permeability and its relationship to OPN were investigated in the present study. The results showed that the expression of ZO-1 and claudin-5 in pulmonary vein were decreased in CLP rats and LPS-treated pulmonary vein VECs. Cx43-overexpressed lentivirus induced the degradation of ZO-1 and claudin-5, while Cx43 RNAi lentivirus abrogated the degradation of ZO-1 and claudin-5 induced by LPS. The vascular permeability and expression of OPN in pulmonary veins were significantly increased in CLP rats and LPS-treated pulmonary vein VECs. Silencing OPN by OPN RNAi lentivirus inhibited the vascular hyperpermeability induced by LPS. Overexpressed Cx43 lentivirus increased the expression of OPN and vascular permeability and downregulated the expression of ZO-1 and claudin-5 in pulmonary vein VECs. Silencing OPN by OPN RNAi lentivirus inhibited the effects of Cx43-overexpressed lentivirus on downregulation of ZO-1 and claudin-5 and vascular hyperpermeability in pulmonary vein VECs. Transfection of specific double-stranded RNA targeting to β-catenin and T-cell factor-4 (Tcf-4) abolished the upregulation of OPN induced by Cx43 overexpression. These results suggest that OPN participates in the regulation of vascular permeability by Cx43 after sepsis. Cx43 upregulation of OPN is via the Tcf-4/β-catenin transcription pathway; OPN increases vascular permeability by downregulating the expression of the tight junction proteins ZO-1 and claudin-5.

Preparation of A Spaceflight: Apoptosis Search in Sutured Wound Healing Models

To prepare the ESA (European Space Agency) spaceflight project “Wound healing and Sutures in Unloading Conditions”, we studied mechanisms of apoptosis in wound healing models based on ex vivo skin tissue cultures, kept for 10 days alive in serum-free DMEM/F12 medium supplemented with bovine serum albumin, hydrocortisone, insulin, ascorbic acid and antibiotics at 32 °C. The overall goal is to test: (i) the viability of tissue specimens; (ii) the gene expression of activators and inhibitors of apoptosis and extracellular matrix components in wound and suture models; and (iii) to design analytical protocols for future tissue specimens after post-spaceflight download. Hematoxylin-Eosin and Elastica-van-Gieson staining showed a normal skin histology with no signs of necrosis in controls and showed a normal wound suture. TdT-mediated dUTP-biotin nick end labeling for detecting DNA fragmentation revealed no significant apoptosis. No activation of caspase-3 protein was detectable. FASL, FADD, CASP3, CASP8, CASP10, BAX, BCL2, CYC1, APAF1, LAMA3 and SPP1 mRNAs were not altered in epidermis and dermis samples with and without a wound compared to 0 day samples (specimens investigated directly post-surgery). BIRC5, CASP9, and FN1 mRNAs were downregulated in epidermis/dermis samples with and/or without a wound compared to 0 day samples. BIRC2, BIRC3 were upregulated in 10 day wound samples compared to 0 day samples in epidermis/dermis. RELA/FAS mRNAs were elevated in 10 day wound and no wound samples compared to 0 day samples in dermis. In conclusion, we demonstrate that it is possible to maintain live skin tissue cultures for 10 days. The viability analysis showed no significant signs of cell death in wound and suture models. The gene expression analysis demonstrated the interplay of activators and inhibitors of apoptosis and extracellular matrix components, thereby describing important features in ex vivo sutured wound healing models. Collectively, the performed methods defining analytical protocols proved to be applicable for post-flight analyzes of tissue specimens after sample return.

The Adverse Effect of Hypertension in the Treatment of Thyroid Cancer with Multi-Kinase Inhibitors

The treatment of thyroid cancer has promising prospects, mostly through the use of surgical or radioactive iodine therapy. However, some thyroid cancers, such as progressive radioactive iodine-refractory differentiated thyroid carcinoma, are not remediable with conventional types of treatment. In these cases, a treatment regimen with multi-kinase inhibitors is advisable. Unfortunately, clinical trials have shown a large number of patients, treated with multi-kinase inhibitors, being adversely affected by hypertension. This means that treatment of thyroid cancer with multi-kinase inhibitors prolongs progression-free and overall survival of patients, but a large number of patients experience hypertension as an adverse effect of the treatment. Whether the prolonged lifetime is sufficient to develop sequelae from hypertension is unclear, but late-stage cancer patients often have additional diseases, which can be complicated by the presence of hypertension. Since the exact mechanisms of the rise of hypertension in these patients are still unknown, the only available strategy is treating the symptoms. More studies determining the pathogenesis of hypertension as a side effect to cancer treatment as well as outcomes of dose management of cancer drugs are necessary to improve future therapy options for hypertension as an adverse effect to cancer therapy with multi-kinase inhibitors.

Angiotensin type-2 (AT-2)-receptor activation reduces renal fibrosis in cyclosporine nephropathy: evidence for blood pressure independent effect

Compound 21 (C21), selective agonist of angiotensin type-2 (AT-2) receptors, shows anti-inflammatory effects in experimental models of hypertension and nephroprotection in diabetes. The aim of the present study was to evaluate the effects of C21 in cyclosporine nephropathy, which is characterized mainly by tubulo-interstitial fibrosis. Ten days before and during the experimental periods, low-salt diet was administered to Sprague–Dawley rats. Cyclosporine-A (CsA; 15 mg/kg per day, intraperitoneal injection) and CsA plus C21 (0.3 mg/kg per day, intraperitoneal injection) were administered for 1 and 4 weeks. Control groups were left without any treatment. Blood pressure (plethysmographic method) and 24 h urinary albumin excretion were measured once a week. At the end of the experimental protocols, the kidneys were excised for histomorphometric analysis of renal fibrosis and for immunohistochemical evaluation of inflammatory infiltrates and type I and type IV collagen expression. After 1 and 4 weeks, the rats treated with CsA showed a significant increase (P<0.01) in blood pressure, no significant changes in urinary albumin excretion and a significant increase (P<0.01) in glomerular and tubulo-interstitial fibrosis and inflammatory infiltrates as compared with the control rats. Treatment with C21 did not modify the CsA dependent increase of blood pressure, which was higher than in control rats, but after 4 weeks of treatment significantly reduced (P<0.01) glomerular and tubulo-interstitial fibrosis, type 1 collagen expression and macrophage infiltration, as compared with rats treated with cyclosporine. The administration of C21 showed a protective effect on cyclosporine nephropathy, decreasing renal fibrosis and macrophage infiltration. These data suggest that C21 may counteract tubulo-interstitial fibrosis, the most potent predictor of the progression of renal diseases.

Buyanghuanwu decoction promotes angiogenesis after cerebral ischemia/reperfusion injury: mechanisms of brain tissue repair

Buyanghuanwu decoction has been shown to protect against cerebral ischemia/reperfusion injury, but the underlying mechanisms remain unclear. In this study, rats were intragastrically given Buyanghuanwu decoction, 15 mL/kg, for 3 days. A rat model of cerebral ischemia/reperfusion injury was established by middle cerebral artery occlusion. In rats administered Buyanghuanwu decoction, infarct volume was reduced, serum vascular endothelial growth factor and integrin αvβ3 levels were increased, and brain tissue vascular endothelial growth factor and CD34 expression levels were increased compared with untreated animals. These effects of Buyanghuanwu decoction were partially suppressed by an angiogenesis inhibitor (administered through the lateral ventricle for 7 consecutive days). These data suggest that Buyanghuanwu decoction promotes angiogenesis, improves cerebral circulation, and enhances brain tissue repair after cerebral ischemia/reperfusion injury.

Identification of transcription factors and gene clusters in rabbit smooth muscle cells during high flow-induced vascular remodeling via microarray

Sustained blood flow, especially high blood flow causes the remodeling of arteries. The molecular mechanism of vascular remodeling has been mainly investigated in cultured cells. However, the in vivo molecular mechanism is poorly understood. In this study, we performed microarray analysis to explore the gene expression profile of smooth muscle cells (SMCs) during vascular remodeling. Transcriptional profiles indicated that 947 genes were differentially expressed in SMCs responding to high flow compared with the sham control, of which 617 genes were up-regulated and 330 genes were down-regulated. Gene ontology analysis revealed the special participation of extracellular matrix related genes during high flow-induced vascular remodeling. KEGG pathway analysis showed the enrichment of metabolism and immune function associated genes in SMCs exposed to high flow. Besides, we also identified 25 differentially expressed transcription factors potentially impacted by hemodynamic insult. Finally, we revealed FOXN4 as a novel transcription factor that could modulate MMP2 and MMP9 transcriptional activity. Collectively, our results revealed major gene clusters and transcription factors in SMCs during vascular remodeling which may provide an insight into the molecular mechanism of vascular remodeling and facilitate the screening of candidate genes for vascular diseases.

Mechanisms of three-dimensional growth of thyroid cells during long-term simulated microgravity

Three-dimensional multicellular spheroids (MCS) of human cells are important in cancer research. We investigated possible mechanisms of MCS formation of thyroid cells. Both, normal Nthy-ori 3–1 thyroid cells and the poorly differentiated follicular thyroid cancer cells FTC-133 formed MCS within 7 and 14 days of culturing on a Random Positioning Machine (RPM), while a part of the cells continued to grow adherently in each culture. The FTC-133 cancer cells formed larger and numerous MCS than the normal cells. In order to explain the different behaviour, we analyzed the gene expression of IL6, IL7, IL8, IL17, OPN, NGAL, VEGFA and enzymes associated cytoskeletal or membrane proteins (ACTB, TUBB, PFN1, CPNE1, TGM2, CD44, FLT1, FLK1, PKB, PKC, ERK1/2, Casp9, Col1A1) as well as the amount of secreted proteins (IL-6, IL-7, IL-8, IL-17, OPN, NGAL, VEGFA). Several of these components changed during RPM-exposure in each cell line. Striking differences between normal and malignant cells were observed in regards to the expression of genes of NGAL, VEGFA, OPN, IL6 and IL17 and to the secretion of VEGFA, IL-17, and IL-6. These results suggest several gravi-sensitive growth or angiogenesis factors being involved in 3D formation of thyroid cells cultured under simulated microgravity.

Interactions between osteopontin and vascular endothelial growth factor: Implications for cancer

For this comprehensive review, 257 publications with the keywords "osteopontin" or "OPN" and "vascular endothelial growth factor" or "VEGF" in PubMed were screened (time frame from year 1996 to year 2014). 37 articles were excluded because they were not focused on the interactions between these molecules, and papers relevant for transformation-related phenomena were selected. Osteopontin (OPN) and vascular endothelial growth factor (VEGF) are characterized by a convergence in function for regulating cell motility and angiogenesis, the response to hypoxia, and apoptosis. Often, they are co-expressed or one molecule induces the other, however, in some settings OPN-associated pathways and VEGF-associated pathways are distinct. Their relationships affect the pathogenesis in cancer, where they contribute to progression and angiogenesis and serve as markers for poor prognosis. The inhibition of OPN may reduce VEGF levels and suppress tumor progression. In vascular pathologies, these two cytokines mediate remodeling, but may also perpetuate inflammation and narrowing of the arteries. OPN and VEGF are elevated and contribute to vascularization in inflammatory diseases.

Anti-vascular endothelial growth factor therapy in breast cancer

Neo-angiogenesis is a critical process for tumor growth and invasion and has become a promising target in cancer therapy. This manuscript reviews three currently relevant anti-angiogenic agents targeting the vascular endothelial growth factor system: bevacizumab, ramucirumab and sorafenib. The efficacy of anti-angiogenic drugs in adjuvant therapy or as neo-adjuvant treatment has been estimated in clinical trials of advanced breast cancer. To date, the overall observed clinical improvements are unconvincing, and further research is required to demonstrate the efficacy of anti-angiogenic drugs in breast cancer treatments. The outcomes of anti-angiogenic therapy have been highly variable in terms of tumor response. New methods are needed to identify patients who will benefit from this regimen. The development of biomarkers and molecular profiling are relevant research areas that may strengthen the ability to focus anti-angiogenic therapy towards suitable patients, thereby increase the cost-effectiveness, currently estimated to be inadequate.

Prevention of diabetic nephropathy by compound 21, selective agonist of angiotensin type 2 receptors, in Zucker diabetic fatty rats

The aim of this study was to evaluate the effect of compound 21 (C21), a selective AT2 receptor agonist, on diabetic nephropathy and the potential additive effect of C21, when associated with losartan treatment, on the development of albuminuria and renal fibrosis in Zucker diabetic fatty (ZDF) rats. The experiments lasted 15 wk (from 5 to 20 wk of age) and were performed in 40 ZDF rats and 12 control lean rats. ZDF rats were divided into 4 groups: 1) 9 rats were treated with losartan; 2) 10 rats were treated with C21; 3) 9 rats were treated with losartan plus C21; and 4) 12 rats were maintained without any treatment. ZDF rats showed an increase in blood glucose level, albuminuria, renal fibrosis, macrophage infiltration, and TNF-α expression and a reduction of glomerular nephrin expression compared with control lean rats. C21 treatment reduced renal glomerular, tubulointerstitial, and perivascular fibrosis, and macrophage infiltration and TNF-α expression in ZDF rats. C21 treatment caused a decrease in albuminuria in ZDF rats up to 11 wk of age. Losartan decreased macrophage infiltration, TNF-α expression, and renal glomerular and perivascular fibrosis, restored glomerular nephrin expression, but did not affect tubulointerstitial fibrosis. Losartan treatment caused a decrease in albuminuria in ZDF rats up to 15 wk of age. At the end of the protocol, only the combination of C21 plus losartan significantly reduced albuminuria in ZDF rats. These data demonstrate that C21 has beneficial effects on diabetic nephropathy, suggesting the combination of C21 and losartan as a novel pharmacological tool to slow the progression of nephropathy in type II diabetes.

Sdc1 overexpression inhibits the p38 MAPK pathway and lessens fibrotic ventricular remodeling in MI rats

Expression of the proteoglycan syndecan-1 (Sdc1) is increased in rats with myocardial infarction (MI). This study investigated the effects of Sdc1 overexpression on ventricular remodeling and cardiac function in MI and explored the possible mechanism through in vivo transfection of rats with recombinant adenovirus-carrying rat Sdc1 cDNA. Sprague-Dawley rats (n = 48) underwent intramyocardial injection in the marginal zone of the infarcted area immediately after ligation of the left anterior descending artery. The rats were divided into four groups according to the solution injected: MI Ad-GFP-Sdc1 transfection group, MI Ad-GFP control group, MI saline group, and sham operation group. Cardiac function and collagen expression of each group were examined, and the roles of inflammation, apoptosis, and p38 MAKP signal transduction pathway were investigated. Compared with the rats in the sham operation group, ventricular weight and collagen content increased in MI rats, and cardiac function declined. Substantial inflammatory cell infiltration was seen in the marginal zone of the infarction area, and a great number of myocardial cells were apoptotic. The p38 MAPK signaling pathway was clearly activated. Rats in the MI Ad-GFP-Sdc1 transfection group showed decreased ventricular weight, reduced collagen synthesis, and significant improvement of ventricular remodeling and cardiac function. Post-MI inflammatory cell infiltration and apoptosis was reduced, and the p38 MAPK signaling pathway was inhibited. Overexpression of Sdc1 can improve post-MI ventricular remodeling, and it is possible that the improvement is achieved through reducing apoptosis and suppressing inflammatory response and through the p38 MAPK signal transduction pathway.

Genomic approach to identify factors that drive the formation of three-dimensional structures by EA.hy926 endothelial cells

Understanding the mechanisms responsible for tube formation by endothelial cells (ECs) is of major interest and importance in medicine and tissue engineering. Endothelial cells of the human cell line EA.hy926 behave ambivalently when cultured on a random positioning machine (RPM) simulating microgravity. Some cells form tube-like three-dimensional (3D) aggregates, while other cells (AD) continue to grow adherently. Between the fifth and seventh day of culturing, the two types of cell growth achieve the greatest balance. We harvested ECs that grew either adherently or as 3D aggregates separately after five and seven days of incubation on the RPM, and applied gene array analysis and PCR techniques to investigate their gene expression profiles in comparison to ECs growing adherently under normal static 1 g laboratory conditions for equal periods of time. Using gene arrays, 1,625 differentially expressed genes were identified. A strong overrepresentation of transient expression differences was found in the five-day, RPM-treated samples, where the number of genes being differentially expressed in comparison to 1 g cells was highest as well as the degree of alteration regarding distinct genes. We found 27 genes whose levels of expression were changed at least 4-fold in RPM-treated cells as compared to 1 g controls. These genes code for signal transduction and angiogenic factors, cell adhesion, membrane transport proteins or enzymes involved in serine biosynthesis. Fifteen of them, with IL8 (interleukin 8) and VWF (von Willebrand factor) the most prominently affected, showed linkages to genes of another 20 proteins that are important in cell structure maintenance and angiogenesis and extended their network of interaction. Thus, the study reveals numerous genes, which mutually influence each other during initiation of 3D growth of endothelial cells.

Biomarkers for anti-angiogenic therapy in cancer

Angiogenesis, the development of new vessels from existing vasculature, plays a central role in tumor growth, survival, and progression. On the molecular level it is controlled by a number of pro- and anti-angiogenic cytokines, among which the vascular endothelial growth factors (VEGFs), together with their related VEGF-receptors, have an exceptional position. Therefore, the blockade of VEGF signaling in order to inhibit angiogenesis was deemed an attractive approach for cancer therapy and drugs interfering with the VEGF-ligands, the VEGF receptors, and the intracellular VEGF-mediated signal transduction were developed. Although promising in pre-clinical trials, VEGF-inhibition proved to be problematic in the clinical context. One major drawback was the generally high variability in patient response to anti-angiogenic drugs and the rapid development of therapy resistance, so that, in total, only moderate effects on progression-free and overall survival were observed. Biomarkers predicting the response to VEGF-inhibition might attenuate this problem and help to further individualize drug and dosage determination. Although up to now no definitive biomarker has been identified for this purpose, several candidates are currently under investigation. This review aims to give an overview of the recent developments in this field, focusing on the most prevalent tumor species.

Renal antifibrotic effect of N-acetyl-seryl-aspartyl-lysyl-proline in diabetic rats

BACKGROUND AND AIM

Diabetic nephropathy is the main cause of end-stage renal disease. N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), a physiological tetrapeptide hydrolyzed by the angiotensin-converting enzyme (ACE), has antifibrotic effects in the cardiovascular system and in the kidney in experimental models of hypertension, heart failure and renal disease. The aim of the study was to evaluate the effect of Ac-SDKP in diabetic nephropathy and the potential additive effect of Ac-SDKP, when compared to ACE inhibitors alone, on the development of renal fibrosis.

METHOD

Diabetes was induced in 28 Sprague-Dawley rats by a single intraperitoneal injection of streptozotocin. Control rats (n = 10) received only buffer solution. An ACE inhibitor (ramipril, 3 mg/kg/day) was administered to 11 diabetic rats. After 2 months, Ac-SDKP (1 mg/kg/day) was administered by osmotic minipumps for 8 weeks to 7 diabetic rats and to 6 diabetic rats treated with ramipril. Osmotic minipumps delivered saline solution in the corresponding sham-treated rats (diabetic rats, n = 10, and ramipril-treated diabetic rats, n = 5).

RESULTS

Diabetic rats showed a significant increase in blood glucose level, urinary albumin excretion and renal fibrosis, and a reduction of glomerular nephrin expression with respect to control rats. Ac-SDKP administration significantly reduced renal fibrosis in diabetic rats, without significantly reducing urinary albumin excretion. Ramipril treatment caused a significant decrease in albuminuria and renal fibrosis and restored glomerular nephrin expression. Administration of Ac-SDKP, in addition to ramipril, further reduced renal fibrosis with respect to ramipril alone, while it did not improve the antiproteinuric effect of ramipril.

CONCLUSION

Ac-SDKP administration reduces renal fibrosis in diabetic nephropathy. Addition of Ac-SDKP to ACE inhibition therapy improves the reduction of renal fibrosis with respect to ACE inhibition alone, suggesting a beneficial effect of this pharmacological association in diabetic nephropathy.

Vascular endothelial growth factor-mediated islet hypervascularization and inflammation contribute to progressive reduction of β-cell mass

Type 2 diabetes (T2D) results from insulin resistance and inadequate insulin secretion. Insulin resistance initially causes compensatory islet hyperplasia that progresses to islet disorganization and altered vascularization, inflammation, and, finally, decreased functional β-cell mass and hyperglycemia. The precise mechanism(s) underlying β-cell failure remain to be elucidated. In this study, we show that in insulin-resistant high-fat diet-fed mice, the enhanced islet vascularization and inflammation was parallel to an increased expression of vascular endothelial growth factor A (VEGF). To elucidate the role of VEGF in these processes, we have genetically engineered β-cells to overexpress VEGF (in transgenic mice or after adeno-associated viral vector-mediated gene transfer). We found that sustained increases in β-cell VEGF levels led to disorganized, hypervascularized, and fibrotic islets, progressive macrophage infiltration, and proinflammatory cytokine production, including tumor necrosis factor-α and interleukin-1β. This resulted in impaired insulin secretion, decreased β-cell mass, and hyperglycemia with age. These results indicate that sustained VEGF upregulation may participate in the initiation of a process leading to β-cell failure and further suggest that compensatory islet hyperplasia and hypervascularization may contribute to progressive inflammation and β-cell mass loss during T2D.

MiR-133a regulates collagen 1A1: potential role of miR-133a in myocardial fibrosis in angiotensin II-dependent hypertension

MicroRNAs play an important role in myocardial diseases. MiR-133a regulates cardiac hypertrophy, while miR-29b is involved in cardiac fibrosis. The aim of this study was to evaluate whether miR-133a and miR-29b play a role in myocardial fibrosis caused by Angiotensin II (Ang II)-dependent hypertension. Sprague-Dawley rats were treated for 4 weeks with Ang II (200  ng/kg/min) or Ang II + irbesartan (50  mg/kg/day in drinking water), or saline by osmotic minipumps. At the end of the experimental period, cardiac miR-133a and miR-29b expression was measured by real-time PCR, and myocardial fibrosis was evaluated by morphometric analysis. A computer-based prediction algorithm led to the identification of collagen 1a1 (Col1A1) as a putative target of miR-133a. A reporter plasmid bearing the 3'-untranslated regions (UTRs) of Col1A1 mRNA was constructed and luciferase assay was performed. MiR-133a suppressed the activity of luciferase when the reporter gene was linked to a 3'-UTR segment of Col1A1 (P < 0.01). Mutation of miR-133a binding sites in the 3'-UTR of Col1A1 mRNA abolished miR-133a-mediated repression of reporter gene activity, showing that Col1A1 is a real target of miR-133a. In vivo, Ang II caused an increase in systolic blood pressure (P < 0.0001, tail cuff) and myocardial fibrosis in presence of a decrease in miR-133a (P < 0.01) and miR-29b (P < 0.01), and an increase in Col1A1 expression (P < 0.01). These effects were abolished by Ang II administration + irbesartan. These data demonstrate a relationship between miR-133a and Col1A1, suggesting that myocardial fibrosis occurring in Ang II-dependent hypertension is regulated by the down-regulation of miR-133a and miR-29b through the modulation of Col1A1 expression.

Osteopontin: an effector and an effect of tumor metastasis

Osteopontin (OPN) is a matricellular protein that is produced by multiple tissues in our body and is most abundant in bone. It is also produced by cancer cells and plays a determinative role in the growth, progression and metastasis of cancer. Clinically, OPN has been reported to be upregulated in tumor cells per se; this is also reflected by increased levels of OPN in the circulation. Thus, increased OPN levels the plasma are an effect of tumor growth and progression. Functionally, high OPN levels are determinative of higher incidence of bone metastases in mouse models and are clinically correlated with metastatic bone disease and bone resorption in advanced breast cancer patients. Several research efforts have been made to therapeutically target and inhibit the activities of OPN. In this article we have reviewed OPN in its role as an effector of critical steps in tumor progression and metastasis, with a particular emphasis on its role in facilitating bone metastasis of breast cancer. We have also addressed the role of the host-derived OPN in influencing the malignant behavior of the tumor cells.

A review of the current research on the role of bFGF and VEGF in angiogenesis

Basic fibroblast growth factor and vascular endothelial growth factor are thought to play a synergistic role in angiogenesis. They are released into the wound bed during haemostasis and promote the formation of new blood vessels.

Prevention of myocardial fibrosis by N-acetyl-seryl-aspartyl-lysyl-proline in diabetic rats

Ac-SDKP (N-acetyl-seryl-aspartyl-lysyl-proline) is a physiological tetrapeptide hydrolysed by ACE (angiotensin-converting enzyme). In experimental models of hypertension, Ac-SDKP has antifibrotic effects in the heart; however, the role of Ac-SDKP in diabetic cardiomyopathy is currently unknown. The aim of the present study was to evaluate the effect of Ac-SDKP on cardiac systolic and diastolic function, and interstitial and perivascular fibrosis in the heart of diabetic rats.Diabetes was induced in 55 Sprague-Dawley rats by streptozotocin injection. Control rats (n=18)underwent only buffer injection.Out of the 55 diabetic rats, 19 were chronically treated with insulin and 13 with the ACEI (ACE inhibitor) ramipril (3 mg x kg(-1 )of body weight x day(-1)). At 2 months after the onset of diabetes, Ac-SDKP (1 mg x kg(-1) of body weight x day(-1)) was administered by osmotic minipumps for 8 weeks to eight control rats, 13 diabetic rats, seven diabetic rats treated with ramipril and nine insulin-treated diabetic rats. Diabetic rats had a significant increase in blood glucose levels. Left ventricular interstitial and perivascular fibrosis, and TGF-beta1 (transforming growth factor-beta1) protein levels were increased in diabetic rats, but not in insulin-treated diabetic rats and ramipril-treated diabetic rats, compared with control rats. Ac-SDKP administration significantly reduced left ventricular interstitial and perivascular fibrosis in diabetic rats and in diabetic rats treated with ramipril. This was accompanied by a significant reduction in active TGF-beta1 and phospho-Smad2/3 protein levels in myocardial tissue of diabetic rats. Echocardiography showed that diabetes was associated with increased end-systolic diameters, and depressed global systolic function and diastolic dysfunction, as assessed by transmitral Doppler velocity profile. These changes were completely reversed by insulin or ramipril treatment. Ac-SDKP treatment partially restored diastolic function in diabetic rats. In conclusion, Ac-SDKP administration in diabetic rats reduces left ventricular interstitial and perivascular fibrosis, active TGF-beta1 and phospho-Smad2/3levels, and improves diastolic function. Taken together, these findings suggest that, by inhibiting theTGF-beta/Smad pathway, Ac-SDKP protects against the development of diabetic cardiomyopathy

Meta-analysis of glioblastoma multiforme versus anaplastic astrocytoma identifies robust gene markers

Background

Anaplastic astrocytoma (AA) and its more aggressive counterpart, glioblastoma multiforme (GBM), are the most common intrinsic brain tumors in adults and are almost universally fatal. A deeper understanding of the molecular relationship of these tumor types is necessary to derive insights into the diagnosis, prognosis, and treatment of gliomas. Although genomewide profiling of expression levels with microarrays can be used to identify differentially expressed genes between these tumor types, comparative studies so far have resulted in gene lists that show little overlap.

Results

To achieve a more accurate and stable list of the differentially expressed genes and pathways between primary GBM and AA, we performed a meta-analysis using publicly available genome-scale mRNA data sets. There were four data sets with sufficiently large sample sizes of both GBMs and AAs, all of which coincidentally used human U133 platforms from Affymetrix, allowing for easier and more precise integration of data. After scoring genes and pathways within each data set, we combined the statistics across studies using the nonparametric rank sum method to identify the features that differentiate GBMs and AAs. We found >900 statistically significant probe sets after correction for multiple testing from the >22,000 tested. We also used the rank sum approach to select >20 significant Biocarta pathways after correction for multiple testing out of >175 pathways examined. The most significant pathway was the hypoxia-inducible factor (HIF) pathway. Our analysis suggests that many of the most statistically significant genes work together in a HIF1A/VEGF-regulated network to increase angiogenesis and invasion in GBM when compared to AA.

Conclusion

We have performed a meta-analysis of genome-scale mRNA expression data for 289 human malignant gliomas and have identified a list of >900 probe sets and >20 pathways that are significantly different between GBM and AA. These feature lists could be utilized to aid in diagnosis, prognosis, and grade reduction of high-grade gliomas and to identify genes that were not previously suspected of playing an important role in glioma biology. More generally, this approach suggests that combined analysis of existing data sets can reveal new insights and that the large amount of publicly available cancer data sets should be further utilized in a similar manner.

Effects of chronic exposure to air pollution from Sao Paulo city on coronary of Swiss mice, from birth to adulthood

To explore the hypothesis that air pollution promotes cardiovascular changes, Swiss mice were continuously exposed, since birth, in two open-top chambers (filtered and nonfiltered for airborne particles <or= 0.3 microm) placed 20 m from a street with heavy traffic in downtown Sao Paulo, twenty-four hours per day for four months. Fine particle (PM(2.5)) concentration was determined gravimetrically; hearts were analyzed by morphometry. There was a reduction of the PM(2.5) inside the filtered chamber (filtered = 8.61+/-0.79 microg/m(3), nonfiltered = 18.05+/-1.25 microg/m(3), p < .001). Coronary arteries showed no evidence of luminal narrowing in the exposed group but presented higher collagen content in the adventitia of LV large-sized and RV midsized vessels (p = .001) and elastic fibers in both tunicae adventitia and intima-media of almost all sized arterioles from both ventricles (p = .03 and p = .001, respectively). We concluded that chronic exposure to urban air since birth induces mild but significant vascular structural alterations in normal individuals, presented as coronary arteriolar fibrosis and elastosis. These results might contribute to altered vascular response and ischemic events in the adulthood.

Anti-Progressive Effect of Neutral Endopeptidase 24.11 (NEP/CD10) on Cervical Carcinoma in vitro and in vivo

OBJECTIVES

Neutral endopeptidase 24.11 (NEP) is known to play important roles in the maintenance of homeostasis or in neoplastic transformation and tumor progression in certain human malignancies through the enzymatic inactivation of bioactive peptides such as endothelin-1 (ET-1), angiotensin-II, and bombesin.

METHODS

In this study, we first investigated NEP expression in cervical carcinoma by immunohistochemical staining and Western blot analysis. Next, we examined NEP functions in vitro and in vivo by generating NEP-overexpressing cervical carcinoma cells.

RESULTS

We found a significant decrease in cellular proliferative and invasive abilities with a reduced ET-1 concentration in the conditioned medium by NEP overexpression in cervical carcinoma CaSki cells, which have an ET-1 autocrine loop. In addition, these potentials were cancelled by blockade of NEP activity with a specific inhibitor. Although vector-transfected CaSki cells could grow even in serum-free media, NEP-overexpressing cells failed to proliferate in these media. Furthermore, we demonstrated that NEP suppressed tumor formation of subcutaneous xenografts using nude mice.

CONCLUSIONS

Our results indicated that NEP functions as a tumor-suppressor gene in cervical carcinoma cells, and its expression may have prognostic significance. Further elucidation of the mechanism underlying the observed effect of NEP will contribute to a better understanding of its role in the pathophysiology of cervical carcinoma.