Identifying long non-coding RNAs involved in heat stress response during wheat pollen development.

Introduction: Wheat is a staple food crop for over one-third of the global population. However, the stability of wheat productivity is threatened by heat waves associated with climate change. Heat stress at the reproductive stage can result in pollen sterility and failure of grain development. Methods: This study used transcriptome data analysis to explore the specific expression of long non-coding RNAs (lncRNAs) in response to heat stress during pollen development in four wheat cultivars. Results and discussion: We identified 11,054 lncRNA-producing loci, of which 5,482 lncRNAs showed differential expression in response to heat stress. Heat-responsive lncRNAs could target protein-coding genes in cis and trans and in lncRNA-miRNA-mRNA regulatory networks. Gene ontology analysis predicted that target protein-coding genes of lncRNAs regulate various biological processes such as hormonal responses, protein modification and folding, response to stress, and biosynthetic and metabolic processes. We also noted some paired lncRNA/protein-coding gene modules and some lncRNA-miRNA-mRNA regulatory modules shared in two or more wheat cultivars. These modules were related to regulating plant responses to heat stress, such as heat-shock proteins and transcription factors, and protein domains, such as MADS-box, Myc-type, and Alpha crystallin/Hsp20 domain. Conclusion: Our results provide the basic knowledge and molecular resources for future functional studies investigating wheat reproductive development under heat stress.

Effect of hydroalcoholic extract of Trigonella foenum-graecum leaves on wound healing in type 1 diabetic rats.

Diabetes describes a group of metabolic disorders characterised by increased blood glucose concentration. People living with diabetes have a higher risk of morbidity and mortality than the general population. In 2015 it was estimated that there were 415 million (uncertainty interval: 340-536 million) people with diabetes aged 20-79 years, and 5.0 million deaths attributable to diabetes. When diabetic patients develop an ulcer, they become at high risk for major complications, including infection and amputation. The pathophysiologic relationship between diabetes and impaired healing is complex. Vascular, neuropathic, immune function, and biochemical abnormalities each contribute to the altered tissue repair. The use of herbal medicine has increased and attracted the attention of many researchers all over the world. In this study, we have evaluated the effect of 500mg/kg hydroalcoholic extract of Trigonella foenum-graecum leaves (TFG-E) on wound healing in diabetic rats using a full-thickness cutaneous incisional wound model. Wounds of treated animals showed better tensiometric indices, accelerated wound contraction, faster re-epithelialisation, improved neovascularisation, better modulation of fibroblasts and macrophage presence in the wound bed and moderate collagen formation.

Benchmarking Standard and Micromechanical Models for Creep and Shrinkage of Concrete Relevant for Nuclear Power Plants.

The creep and shrinkage of concrete play important roles for many nuclear power plant (NPP) and engineering structures. This paper benchmarks the standard and micromechanical models using a revamped and appended Northwestern University database of laboratory creep and shrinkage data with 4663 data sets. The benchmarking takes into account relevant concretes and conditions for NPPs using 781 plausible data sets and 1417 problematic data sets, which cover together 47% of the experimental data sets in the database. The B3, B4, and EC2 models were compared using the coefficient of variation of error (CoV) adjusted for the same significance for short-term and long-term measurements. The B4 model shows the lowest variations for autogenous shrinkage and basic and total creep, while the EC2 model performs slightly better for drying and total shrinkage. In addition, confidence levels at 5, 10, 90, and 95% are quantified in every decade. Two micromechanical models, Vi(CA)2T and SCK CEN, use continuum micromechanics for the mean field homogenization and thermodynamics of the water-pore structure interaction. Validations are carried out for the 28-day Young's modulus of concrete, basic creep compliance, and drying shrinkage of paste and concrete. The Vi(CA)2T model is the second best model for the 28-day Young's modulus and the basic creep problematic data sets. The SCK CEN micromechanical model provides good prediction for drying shrinkage.

Circular RNAs modulate the floral fate acquisition in soybean shoot apical meristem.

BACKGROUND: Soybean (Glycine max), a major oilseed and protein source, requires a short-day photoperiod for floral induction. Though key transcription factors controlling flowering have been identified, the role of the non-coding genome is limited. Circular RNAs (circRNAs) recently emerged as a novel class of RNAs with critical regulatory functions. However, a study on circRNAs during the floral transition of a crop plant is lacking. We investigated the expression and potential function of circRNAs in floral fate acquisition by soybean shoot apical meristem in response to short-day treatment. RESULTS: Using deep sequencing and in-silico analysis, we denoted 384 circRNAs, with 129 exhibiting short-day treatment-specific expression patterns. We also identified 38 circRNAs with predicted binding sites for miRNAs that could affect the expression of diverse downstream genes through the circRNA-miRNA-mRNA network. Notably, four different circRNAs with potential binding sites for an important microRNA module regulating developmental phase transition in plants, miR156 and miR172, were identified. We also identified circRNAs arising from hormonal signaling pathway genes, especially abscisic acid, and auxin, suggesting an intricate network leading to floral transition. CONCLUSIONS: This study highlights the gene regulatory complexity during the vegetative to reproductive transition and paves the way to unlock floral transition in a crop plant.

Role of long non-coding RNAs in rice reproductive development.

Rice is a staple crop, feeding over half of the global population. The future demand of population growth and climate change requires substantial rice improvement. Recent advances in rice genomics have highlighted the vital role of the non-coding part of the genome. The protein-coding regions account for only a tiny portion of the eukaryotic genome, and most of the genomic regions transcribe copious amounts of non-coding RNAs. Of these, the long non-coding RNAs, including linear non-coding RNAs (lncRNAs) and circular non-coding RNAs (circRNAs), have been shown to play critical roles in various developmental processes by regulating the expression of genes and functions of proteins at transcriptional, post-transcriptional and post-translational levels. With the advances in next-generation sequencing technologies, a substantial number of long non-coding RNAs have been found to be expressed in plant reproductive organs in a cell- and tissue-specific manner suggesting their reproductive development-related functions. Accumulating evidence points towards the critical role of these non-coding RNAs in flowering, anther, and pollen development, ovule and seed development and photoperiod and temperature regulation of male fertility. In this mini review, we provide a brief overview of the role of the linear and circular long non-coding RNAs in rice reproductive development and control of fertility and crop yield.

Effect of bromelain on mast cell numbers and degranulation in diabetic rat wound healing.

OBJECTIVE: Many studies have revealed the prominent roles of mast cells in wound healing, including inflammatory reactions, angiogenesis and extracellular matrix reabsorption. In the present study, we aimed to assess the probable therapeutic features of bromelain on wound contraction and mast cell degranulation in wound healing in experimental diabetic animals. METHOD: Male rats were grouped as control, vehicle and experiment. Skin wounds were generated in all groups. Treatments were applied with distilled water and with bromelain (BR) intraperitoneally in the vehicle and experimental groups, respectively. Following skin wound generation, animals were euthanised on days 3, 5, 7 and 15. We gathered 16,800 microscopic images to count the mast cells and degranulation level (Image J software). The wound contraction index was assessed both microscopically (Image J software) and macroscopically (time-lapse photography). The meshwork evaluation method was used to assess wound healing. RESULTS: Time-lapse photography revealed that the BR significantly (p<0.05) accelerated wound contraction and healing. BR significantly (p<0.05) increased the total number of mast cells in all experimental groups on days 5 and 7. The count of grade III (degranulated) mast cells was reduced significantly (p<0.05) on days 5 and 7 in experimental groups compared to control and vehicle groups. CONCLUSION: In this study, the rate of wound healing was accelerated considerably following BR administration. In addition, this agent decreased the count of degranulated mast cells, leading to wound contraction and healing.

Circular RNAs Repertoire and Expression Profile during Brassica rapa Pollen Development.

Circular RNAs (circRNAs) are covalently closed RNA molecules generated by the back-splicing of exons from linear precursor mRNAs. Though various linear RNAs have been shown to play important regulatory roles in many biological and developmental processes, little is known about the role of their circular counterparts. In this study, we performed high-throughput RNA sequencing to delineate the expression profile and potential function of circRNAs during the five stages of pollen development in Brassica rapa. A total of 1180 circRNAs were detected in pollen development, of which 367 showed stage-specific expression patterns. Functional enrichment and metabolic pathway analysis showed that the parent genes of circRNAs were mainly involved in pollen-related molecular and biological processes such as mitotic and meiotic cell division, DNA processes, protein synthesis, protein modification, and polysaccharide biosynthesis. Moreover, by predicting the circRNA-miRNA network from our differentially expressed circRNAs, we found 88 circRNAs with potential miRNA binding sites, suggesting their role in post-transcriptional regulation of the genes. Finally, we confirmed the back-splicing sites of nine selected circRNAs using divergent primers and Sanger sequencing. Our study presents the systematic analysis of circular RNAs during pollen development and forms the basis of future studies for unlocking complex gene regulatory networks underpinning reproduction in flowering plants.

Genome-Wide In Silico Identification and Comparative Analysis of Dof Gene Family in Brassica napus.

DNA binding with one finger (DOF) proteins are plant-specific transcription factors that play roles in diverse plant functions. However, little is known about the DOF protein repertoire of the allopolyploid crop, Brassica napus. This in silico study identified 117 Brassica napus Dof genes (BnaDofs) and classified them into nine groups (A, B1, B2, C1, C2.1, C2.2, C3, D1, and D2), based on phylogenetic analysis. Most members belonging to a particular group displayed conserved gene structural organisation and protein motif distribution. Evolutionary analysis exemplified that the divergence of the Brassica genus from Arabidopsis, the whole-genome triplication event, and the hybridisation of Brassica oleracea and Brassica rapa to form B. napus, followed by gene loss and rearrangements, led to the expansion and divergence of the Dof transcription factor (TF) gene family in B. napus. So far, this is the largest number of Dof genes reported in a single eudicot species. Functional annotation of BnaDof proteins, cis-element analysis of their promoters, and transcriptomic analysis suggested potential roles in organ development, the transition from the vegetative to the reproductive stage, light responsiveness, phytohormone responsiveness, as well as potential regulatory roles in abiotic stress. Overall, our results provide a comprehensive understanding of the molecular structure, evolution, and possible functional roles of Dof genes in plant development and abiotic stress response.

Conformational changes of ß-thalassemia major hemoglobin and oxidative status of plasma after in vitro exposure to extremely low-frequency electromagnetic fields: An artificial neural network analysis.

Electromagnetic fields (EMF) can generate reactive oxygen species and induce oxidative modifications. We investigated the effects of extremely low-frequency electromagnetic fields (ELF-EMF) on oxidative status of plasma and erythrocytes in ß-thalassemia major patients and design artificial neural networks (ANN) for evaluating the oxyHb concentration. Blood samples were obtained from age and sex-matched healthy donors (n = 12) and major ß-thalassemia patients (n = 12) and subjected to 0.5 and 1 mT and 50 Hz of EMF. Plasma oxidative status was estimated after 1 and 2 h exposure to ELE-EMF. Structural changes of plasma proteins were investigated by Native PAGE and SDS-PAGE. Moreover; multilayer perceptron (MLP) method was applied for designing a feed forward ANN model to predict the impact of these oxidative and antioxidative parameters on oxyHb concentration. Two hour exposure to ELF-EMF induced significant oxidative changes on major ß-thalassemia samplesElectrophoretic profiles showed two high molecular weight (HMW) protein aggregates in plasma samples from healthy donors and major ß-thalassemia patients. According to our ANN design, the main predictors of oxyHb concentration were optical density of Hb at 542, 340, 569, 630, 577, and 420 nm and metHb and hemichrome (HC) concentration. Accuracy of the proposed ANN model was shown by predicted by observed chart (y = 1.3 + 0.96x, R2 = 0.942), sum of squares errors (SSR), and relative errors (RE). Our results showed the detailed effects of ELF-EMF on Hb structure and oxidative balance of plasma in major ß-thalassemia patients and significance of ANN analysis during normal and pathologic conditions.

Use of bromelain in cutaneous wound healing in streptozocin-induced diabetic rats: an experimental model.

OBJECTIVE: To assess the effect of bromelain on different aspects of the wound healing process in type 1 diabetic rats. METHOD: In this study, 112 streptozocin-diabetic (type 1) male Wistar rats were euthanised; 28 each on days three, five, seven and 15, after a wound incision had been made. To estimate changes in a number of different cellular and tissue elements, histological sections were provided from all wound areas and stained with haematoxylin and eosin. Some 1.056mm2 of total wound area from all specimens were evaluated, by assessment of 4200 microscope photos provided from all histological sections, by stereological methods. A biomechanical test of each wound area was performed with an extensometer to evaluate the work-up to maximum force and maximum stress of the healed wound on day 15. RESULTS: In the experimental groups, bromleain caused significant wound contraction and reduced granulation tissue formation by day 7 (p=0.003); increased neovasculars (new small vessels that appear in the wound area during wound healing) on days three, five and seven (p=0.001); significantly increased fibroblasts on day five but decreased by day seven (p=0.002); and significantly decreased macrophage numbers and epithelium thickness on all days of study (p=0.005). Wound strength significantly increased in experimental groups by day 15. CONCLUSION: Bromelain has a wide range of therapeutic benefits, but in most studies the mode of its action is not properly understood. It has been proved that bromelain has no major side effects, even after prolonged use. According to the results of this study, bromelain can be used as an effective health supplement to promote and accelerate wound healing indices, reduce inflammation and improve biomechanical parameters in diabetic wounds.

The effect of vitamin C on the gene expression profile of sperm protamines in the male partners of couples with recurrent pregnancy loss: A randomized clinical trial.

OBJECTIVE: Since sperm abnormalities are known to be a major reason for recurrent pregnancy loss (RPL), any defects in DNA structure and chromatin condensation can place embryos at risk in the early stage of development and implantation. As antioxidants such as vitamin C may play a protective role against the destruction of protamine genes in sperm chromatin, this study was conducted to evaluate the effects of vitamin C on chromatin and the expression of protamine genes in the male partners of couples with RPL. METHODS: Twenty male partners of couples with RPL were selected as the intervention group and received vitamin C supplementation (250 mg daily for 3 months). Healthy fertile men (n=20) were included as controls. Sperm chromatin, DNA integrity, and the expression levels of protamine genes were evaluated before and after treatment. RESULTS: Significant differences were found in sperm morphology, protamine deficiency, and apoptosis between the two groups and before and after vitamin C administration. A significant change was found in mRNA levels of PRM1, PRM2, and the PRM1/PRM2 ratio after treatment. CONCLUSION: Daily oral administration of vitamin C may improve human sperm parameters and DNA integrity by increasing protamine gene expression levels in the male partners of couples with RPL. The beneficial effects of vitamin C supplementation as an antioxidant for the male partners of couples with RPL could lead to improved pregnancy outcomes in these cases.

A Novel Single Domain Antibody Targeting FliC Flagellin of Salmonella enterica for Effective Inhibition of Host Cell Invasion.

The enteric pathogen, Salmonella enterica is a major cause of human gastroenteritis globally and with increasing bacterial resistance to antibiotics, alternative solutions are urgently needed. Single domain antibodies (sdAbs), the smallest antibody fragments that retain antigen binding specificity and affinity, are derived from variable heavy-chain only fragments (VHH) of camelid heavy-chain-only immunoglobulins. SdAbs typically contain a single disulfide bond simplifying recombinant protein production in microbial systems. These factors make sdAbs ideally suited for the development of effective anti-bacterial therapeutics. To this end, we generated an anti-Salmonella VHH library from which we screened for high affinity sdAbs. We present a novel sdAb (Abi-Se07) that targets the Salmonella virulence factor, FliC, required for bacterial motility and invasion of host cells. We demonstrate that Abi-Se07 bound FliC with a K D of 16.2 ± 0.1 nM. In addition, Abi-Se07 exhibited cross-serovar binding to whole cells of S. enterica serovar Typhimurium, Heidelberg, and Hadar. Abi-Se07 significantly inhibited bacterial motility and significantly reduced S. enterica colonization in a more native environment of chicken jejunum epithelium. Taken together, we have identified a novel anti-Salmonella sdAb and discuss future efforts toward therapeutic development.

Effect of Omegaven on mast cell concentration in diabetic wound healing.

Diabetic wound healing is a complicated process. In all over the world 15% of 200 million diabetic people suffer from diabetic foot problems. Mast cells are known to participate in three phases of wound healing: the inflammatory reaction, angiogenesis and extracellular-matrix reabsorption. The inflammatory reaction is mediated by released histamine and arachidonic acid metabolites. Omega-3 fatty acids alter proinflammatory cytokine production during wound healing which affects the presence of inflammatory cells in wound area as well, but how this events specifically influences the presence of mast cells in wound healing is not clearly understood. This study is conducted to determine the effect of Omegaven, eicosapentaenoic (EPA) and docosahexaenoic (DHA) on pattern of presence of mast cells in diabetic wound area. Diabetic male wistar rats were euthanized at 1, 3, 5, 7 and 15 days after the excision was made. To estimate the number of mast cells histological sections were provided from wound area and stained with toluidine blue. In this relation wound area (8400 microscopic field, 45.69 mm2) were examined by stereological methods by light microscope. We found that comparing experimental and control group, omega-3 fatty acids significantly decreased wound area in day 7 and also the number of grade three mast cells in day 3 and 5. We also found that wound strength has significantly increased in experimental group at day 15.

Omegaven Improves Skin Morphometric Indices in Diabetic Rat Model Wound Healing.

The global prevalence of diabetes is estimated to be 200 million people, and it is likely to increase to 333 million people by 2025. Different cells, are known to participate in three main phases of wound healing. Omega-3 fatty acids influence cytokines and growth factors which affects the presence of inflammatory cells in wound area as well, but how this event specifically influences the role of fibroblasts, macrophages and angiogenesis in wound healing is not obviously understood. In this experimental study seventy male Wistar rats after induction of diabetes type-one by streptozotocin (STZ) (55 mg/kg) were divided into two groups, Experimental group receiving omegaven intraperitoneally and control group which underwent the injection of mineral oil. Streptozotocin was used for the induction of diabetes type 1. Diabetic male wistar rats were scarified at 1, 3, 5, 7 and 15 days after the excision was made. To estimate orphometric indices, histological sections were provided by stereological methods. It was found that wound area significantly decreased on day 7 in experimental group by omega-3 fatty acids. The number of fibroblasts increased significantly on days 5 and 7 in the experimental group. The number of neovascular significantly decreased on day 7 in the experimental group. This study implied that it seems omegaven is able to improve morphometric indices during wound healing and make healing faster.

Histological Changes of the Ovary in Pregnant Mice Vaginally Exposed to Toxoplasma gondii.

BACKGROUND: Congenital toxoplasmosis is one cause of abortion. Infection can disrupt ovarian cycles and because toxoplasmosis is an infectious disease may have a similar effect on the ovaries. The purpose of this study was to investigate the pathological changes in the ovaries due to toxoplasmosis. METHODS: Tachyzoites of Toxoplasma gondii were harvested from peritoneal fluid of mice, experimentally infected. Two females and one male mouse were housed per cage for mating in the overnight. The pregnant mice were divided into experimental and control groups. Experimental group were infected by parasite but the control group received the normal saline. The experimental and control mice were euthanized. Ovaries and uterine horns of animals were removed and prepared for light microscopy. RESULTS: Ovaries of infected pregnant mice presented gross morphological differences compared to the control groups. In ovaries of experimental groups, changes of corpus luteum were observed. The comparison of experimental and control groups revealed that the number of primary follicles, secondary follicle, atretic primary follicles and atretic secondary follicles had significant differences (P≤0.001). CONCLUSION: Toxoplasma gondii alters ovarian follicular growth and development in mice. In addition, it alters number of different phases of follicles and corpus luteum in ovaries of mice.

Effect of Pentoxifylline Administration on Mast Cell Numbers and Degranulation in a Diabetic and Normoglycemic rat Model Wound Healing.

BACKGROUND: Wound healing is a complicated and integrated process. Researches in the molecular level on human and animal models have indicated several molecular changes related to the effect of diabetes on wound healing process. OBJECTIVES: Increasing number of researches implicates the influence of mast cells on skin wound repairing. In this study the effect of systemic pentoxifylline (PTX) administration (daily dose of 25mg/kg twice a day, for 7 consecutive days) on normoglycemic (NG) and diabetic (DB) wistar rat's wound healing by secondary intention was studied. MATERIALS AND METHODS: In this study forty eight wistar rats (weighting 250-350g) were divided randomly in two groups: Normoglycemic and diabetic, each group was divided into experimental and control groups, experimental received intraperitoneal (PTX) and controls received distilled water (DW). The number and maturing process of mast cells was evaluated by counting the number of types of mast cells [1][2][3] microscopically and by stereological methods on day 3 and 7 after surgery. RESULTS: In this study it was cleared that in wound healing process PTX caused increasing the number of type 2 mast cells in all experimental groups(P = 0.00). In normoglycemic experimental group, receiving PTX there was decrease in the number of type3 mast cells, comparing experimental NG groups (P = 0.00). CONCLUSIONS: In all PTX treated groups delay in converting type 2 into type 3 mast cell was seen. Pentoxifylline causes decreasing mast cell degranulation in wound healing process.

Phospholipids and oxophospholipids in atherosclerotic plaques at different stages of plaque development.

We identified and quantified the hydroperoxides, hydroxides, epoxides, isoprostanes, and core aldehydes of the major phospholipids as the main components of the oxophospholipids (a total of 5-25 pmol/micromol phosphatidylcholine) in a comparative study of human atheroma from selected stages of lesion development. The developmental stages examined included fatty streak, fibrous plaque, necrotic core, and calcified tissue. The lipid analyses were performed by normal-phase HPLC with on-line electrospray MS using conventional total lipid extracts. There was great variability in the proportions of the various oxidation products and a lack of a general trend. Specifically, the early oxidation products (hydroperoxides and epoxides) of the glycerophosphocholines were found at the advanced stages of the plaques in nearly the same relative abundance as the more advanced oxidation products (core aldehydes and acids). The anticipated linear accumulation of the more stable oxidation products with progressive development of the atherosclerotic plaque was not apparent. It is therefore suggested that lipid infiltration and/or local peroxidation is a continuous process characterized by the formation and destruction of both early and advanced products of lipid oxidation at all times. The process of lipid deposition appears to have been subject to both enzymatic and chemical modification of the normal tissue lipids. Clearly, the appearance of new and disproportionate old lipid species excludes randomness in any accumulation of oxidized LDL lipids in atheroma.

Defective lung vascular development and fatal respiratory distress in endothelial NO synthase-deficient mice: a model of alveolar capillary dysplasia?

Endothelium-derived NO plays a critical role in the regulation of cardiovascular function and structure, as well as acting as a downstream mediator of the angiogenic response to numerous vascular growth factors. Although endothelial NO synthase (eNOS)-deficient mice are viable, minor congenital cardiac abnormalities have been reported and homozygous offspring exhibit high neonatal mortality out of proportion to the severity of these defects. The aim of the present report was to determine whether abnormalities of the pulmonary vascular development could contribute to high neonatal loss in eNOS-deficient animals. We now report that eNOS-deficient mice display major defects in lung morphogenesis, resulting in respiratory distress and death within the first hours of life in the majority of animals. Histological and molecular examination of preterm and newborn mutant lungs demonstrated marked thickening of saccular septae, with evidence of reduced surfactant material. Lungs of eNOS-deficient mice also exhibited a striking paucity of distal arteriolar branches and extensive regions of capillary hypoperfusion, together with misalignment of pulmonary veins, which represent the characteristic features of alveolar capillary dysplasia. We conclude that eNOS plays a previously unrecognized role in lung development, which may have relevance for clinical syndromes of neonatal respiratory distress.

Decorin inhibition of PDGF-stimulated vascular smooth muscle cell function: potential mechanism for inhibition of intimal hyperplasia after balloon angioplasty.

Decorin is a small proteoglycan that binds to transforming growth factor-beta (TGF-beta) and inhibits its activity. However, its interaction with platelet-derived growth factor (PDGF), involved in arterial repair after injury, is not well characterized. The objectives of this study were to assess decorin-PDGF and decorin-PDGF receptor (PDGFR) interactions, the in vitro effects of decorin on PDGF-stimulated smooth muscle cell (SMC) functions and the in vivo effects of decorin overexpression on arterial repair in a rabbit carotid balloon-injury model. Decorin binding to PDGF was demonstrated by solid-phase binding and affinity cross-linking assays. Decorin potently inhibited PDGF-stimulated PDGFR phosphorylation. Pretreatment of rabbit aortic SMC with decorin significantly inhibited PDGF-stimulated cell migration, proliferation, and collagen synthesis. Decorin overexpression by adenoviral-mediated gene transfection in balloon-injured carotid arteries significantly decreased intimal cross-sectional area and collagen content by approximately 50% at 10 weeks compared to beta-galactosidase-transfected or balloon-injured, non-transfected controls. This study shows that decorin binds to PDGF and inhibits its stimulatory activity on SMCs by preventing PDGFR phosphorylation. Decorin overexpression reduces intimal hyperplasia and collagen content after arterial injury. Decorin may be an effective therapy for the prevention of intimal hyperplasia after balloon angioplasty.

Angiogenic actions of angiopoietin-1 require endothelium-derived nitric oxide.

Angiopoietin1 (Ang1) is a novel angiogenic factor with important actions on endothelial cell (EC) differentiation and vascular maturation. Ang1 has been shown to prevent EC apoptosis through activation of PI3-kinase/Akt, a pathway that is also known to activate endothelium nitric oxide synthase (eNOS). Therefore, we hypothesized that the angiogenic effects of Ang1 would also be dependent on the PI3-kinase/Akt pathway, possibly mediated by increased eNOS activity and NO release. Treatment of human umbilical vein endothelial cells with recombinant Ang1* (300 ng/ml) for 15 minutes resulted in PI3-kinase-dependent Akt phosphorylation, comparable to that observed with vascular endothelial growth factor (VEGF) (50 ng/ml), and increased NO production in a PI3-kinase/Akt-dependent manner. Capillary-like tube formation induced by Ang1* in fibrin matrix at 24 hours (differentiation index, DI: 13.74 +/- 0.76 versus control 1.71 +/- 0.31) was abolished in the presence of the selective PI3-kinase inhibitor, LY294002 (50 micro mol/L) (DI: 0.31 +/- 0.31, P < 0.01) or the NOS inhibitor, L-NAME (3 mmol/L) (DI: 4.10 +/- 0.59, P < 0.01). In subcutaneous Matrigel implants in vivo, addition of recombinant Ang1* or wild-type Ang1 from conditioned media of COS-1 cells transfected with a pFLAG Ang1 expression vector, induced significant neovascularization to a degree similar to VEGF. Finally, angiogenesis in vivo in response to both Ang1 and VEGF was significantly reduced in eNOS-deficient compared with wild-type mice. In summary, our results demonstrate for the first time that endothelial-derived NO is required for Ang1-induced angiogenesis, and that the PI3-kinase signaling mediates the activation of eNOS and NO release in response to Ang1.