Neovascularization Levels Research Articles

Multifunctional Photothermal Nanorods for Targeted Treatment of Drug-Resistant Bacteria-Induced Wound Healing.

The challenge of drug-resistant bacteria-induced wound healing in clinical and public healthcare settings is significant due to the negative impacts on surrounding tissues and difficulties in monitoring the healing progress. We developed photothermal antibacterial nanorods (AuNRs-PU) with the aim of selectively targeting and combating drug-resistant Pseudomonas aeruginosa (P. aeruginosa). The AuNRs-PU were engineered with a bacterial-specific targeting polypeptide (UBI29-41) and a bacterial adhesive carbohydrate polymer composed of galactose and phenylboronic acid. The objective was to facilitate sutureless wound closure by specially distinguishing between bacteria and nontarget cells and subsequently employing photothermal methods to eradicate the bacteria. AuNRs-PU demonstrated high photothermal conversion efficiency in 808 nm laser and effectively caused physical harm to drug-resistant P. aeruginosa. By integrating the multifunctional bacterial targeting copolymer onto AuNRs, AuNRs-PU showed rapid and efficient bacterial targeting and aggregation in the presence of bacteria and cells, consequently shielding cells from bacterial harm. In a diabetic rat wound model, AuNRs-PU played a crucial role in enhancing healing by markedly decreasing inflammation and expediting epidermis formation, collagen deposition, and neovascularization levels. Consequently, the multifunctional photothermal therapy shows promise in addressing the complexities associated with managing drug-resistant infected wound healing.

Development of melatonin-embedded PLGA-PEG6000 nanofiber biomaterial, and investigation of the effects on abdominal adhesion formation

Abdominal adhesions are still among the most common postsurgical peritoneal inflammation-related complications. Adhesion-related disorders are still highly costly and prevalent due to advances in surgical techniques, treatment methods, and various drugs. The present study aimed to investigate the effects of Poly ( D,L-lactide-co-glycolide) (PLGA)- polyethylene glycol (PEG6000) Nanofiber + Melatonin on the abdominal adhesion model in rats. For this purpose, PLGA-PEG6000 Nanofiber + Melatonin matrix was fabricated and implanted in an experimental abdominal adhesion model in rats. Our study consisted of an in vitro and an in vivo part. The degradation and release profile of the matrix and Melatonin (Mel) embedded matrix was performed in vitro. In vivo, the procedure was carried out with 18 Wistar male rats. Rats were divided into three groups as follows: Sham, Matrix, and Mel + Matrix, respectively. Consequent to degradation and release profiling in vitro, an experimental adhesion model was created and fabricated pure matrix (2 × 2 cm2), and matrix (2 × 2 cm2, 0.25 mg melatonin/per matrix embedded) was applied to injury area in related groups. Intra-abdominal adhesion scores were determined on post-op 21st day, under general anesthesia. Following, cecum, peritoneal tissue, and adhesive bands were harvested. Macroscopic analysis (severity of adhesion formation), Hematoxlyn&Eosin and Masson’s Trichrome staining (for the examination of the levels of infiltration of inflammatory cells, fibrosis, and neovascularization) were performed for the evaluation of the effects of Mel embedded and pure matrix Our results indicated that PLGA-PEG6000 Nanofiber + Melatonin matrix was degraded completely in rats abdominal cavity and significantly reduced adhesion formation compared to other groups macroscopically ( p < 0.05). On the other hand, the histopathological analysis indicated that the fabricated matrix reduced inflammatory cell infiltration, fibrosis, and neovascularization levels.

Preliminary Study on the Effect of Intrastromal Anti-Vascular Endothelial Growth Factor Injections on Corneal Neovascularization Using Anterior Segment Optical Coherence Tomography Angiography

Background Corneal neovascularization, is a serious condition affecting large percentage of the population. Not only does corneal neovascularization decrease vision and cause corneal edema, but also, it is highly associated with graft rejections. Anti-VEGF has been used in many studies to treat corneal neovascularization with promising results. Recently, evaluation of corneal neovascularization using Optical Coherence Tomography Angiography (OCTA) has been explored and has shown to be promising. Objective To evaluate the effect of intrastromal injection of Anti-VEGF using the swept source anterior segment OCTA on corneal neovascularization. Patients and Methods This pilot study was done in a cohort, prospective manner. The study was done on 10 eyes of 10 patients with corneal neovascularization who were planned for keratoplasty or after keratoplasty. Intrastromal injection of Anti-VEGF using a 30 Gauge needle at a concentration of 5 mg/0.2 mL [2.5%] was done for patients involved in this study. OCTA was done 48 hours before injection, 1 week and 1 month after injection. OCTA images were compared to evaluate the effect of Anti-VEGF on corneal neovascularization. Results Compared with the pre-operative period, at 1 week postoperatively, 9 cases have shown decreased corneal neovascularization, with only 1 case that showed no regression and seemed to be unresponsive to the single injection of Anti-VEGF. At 1 month period, 8 cases had increased vascularization (re-vascularized), 1 case had decreased vascularization again (completely disappeared) and 1 case stayed the same with no change. Cases that have revascularized, have not returned back to the original vascularization level. Using OCTA colored, black and white images, we were able to picture blood vessels in 3-D image and detect subtle changes in corneal neovascularization. Using the OCTA cross-sectional images, we were able to estimate the vessels depths. In 6 cases, vessels were located in the posterior 25% of the cornea (Deep), in 2 cases they were located in the anterior 25 % (Superficial) and in 2 cases they were between the anterior 25 % and the posterior 25% (Mid-stromal). Vessel density was not possible to calculate in this study. Conclusion Bevacizumab intrastromal injections seem to be a very effective temporary method in decreasing corneal neovascularization despite the level of neovascularization. Repeated Bevacizumab injections might be needed to eliminate corneal neovascularization completely. Bevacizumab seems to have a peak action at 1 week period and then its effect seems to ware off gradually. OCTA was able to visualize vessels in 3-D image, even under vascularized corneal scars. OCTA was able to recognize subtle changes in corneal neovascularization, that were not visible by slit lamp.

The atypical chemokine receptor-2 fine-tunes the immune response in herpes stromal keratitis.

Herpes stromal keratitis (HSK) is a blinding corneal disease caused by herpes simplex virus-1 (HSV-1), a common pathogen infecting most of the world's population. Inflammation in HSK is chemokine-dependent, particularly CXCL10 and less so the CC chemokines. The atypical chemokine receptor-2 (ACKR2) is a decoy receptor predominantly for pro-inflammatory CC chemokines, which regulates the inflammatory response by scavenging inflammatory chemokines thereby modulating leukocyte infiltration. Deletion of ACKR2 exacerbates and delays the resolution of the inflammatory response in most models. ACKR2 also regulates lymphangiogenesis and mammary duct development through the recruitment of tissue-remodeling macrophages. Here, we demonstrate a dose-dependent upregulation of ACKR2 during corneal HSV-1 infection. At an HSV inoculum dose of 5.4 x 105 pfu, but not at higher dose, ACKR2 deficient mice showed prolonged clinical signs of HSK, increased infiltration of leukocytes and persistent corneal neovascularization. Viral clearance and T cell activation were similar in ACKR2-/- and wild type mice, despite a transient diminished expression of CD40 and CD86 in dendritic cells. The data suggest that ACKR2 fine-tunes the inflammatory response and the level of neovascularization in the HSK.

BMSCs and Osteoblast-Engineered ECM Synergetically Promotes Osteogenesis and Angiogenesis in an Ectopic Bone Formation Model.

Bone mesenchymal stem cells (BMSCs) have been extensively used in bone tissue engineering because of their potential to differentiate into multiple cells, secrete paracrine factors, and attenuate immune responses. Biomaterials are essential for the residence and activities of BMSCs after implantation in vivo. Recently, extracellular matrix (ECM) modification with a favorable regenerative microenvironment has been demonstrated to be a promising approach for cellular activities and bone regeneration. The aim of the present study was to evaluate the effects of BMSCs combined with cell-engineered ECM scaffolds on osteogenesis and angiogenesis in vivo. The ECM scaffolds were generated by osteoblasts on the small intestinal submucosa (SIS) under treatment with calcium (Ca)-enriched medium and icariin (Ic) after decellularization. In a mouse ectopic bone formation model, the SIS scaffolds were demonstrated to reduce the immune response, and lower the levels of immune cells compared with those in the sham group. Ca/Ic-ECM modification inhibited the degradation of the SIS scaffolds in vivo. The generated Ca/Ic-SIS scaffolds ectopically promoted osteogenesis according to the results of micro-CT and histological staining. Moreover, BMSCs on Ca/Ic-SIS further increased the bone volume percentage (BV/TV) and bone density. Moreover, angiogenesis was also enhanced by the Ca/Ic-SIS scaffolds, resulting in the highest levels of neovascularization according to the data ofCD31 staining. In conclusion, osteoblast-engineered ECM under directional induction is a promising strategy to modify biomaterials for osteogenesis and angiogenesis. BMSCs synergetically improve the properties of ECM constructs, which may contribute to the repair of large bone defects.

Decorin regulates collagen fibrillogenesis during corneal wound healing in mouse in vivo

A characteristic rigid spatial arrangement of collagen fibrils in the stroma is critical for corneal transparency. This unique organization of collagen fibrils in corneal stroma can be impacted by the presence and interactions of proteoglycans and extracellular matrix (ECM) proteins in a corneal microenvironment. Earlier studies revealed that decorin, a leucine-rich proteoglycan in stroma, regulates keratocyte-collagen matrix assembly and wound healing in the cornea. This study investigated the role of decorin in the regulation of stromal fibrillogenesis and corneal transparency in vivo employing a loss-of-function genetic approach using decorin null (dcn−/−) and wild type (dcn+/+) mice and a standard alkali-injury model. A time-dependent ocular examinations with Slit lamp microscope in live animals assessed corneal clarity, haze, and neovascularization levels in normal and injured eyes. Morphometric changes in normal and injured dcn+/+ and dcn−/− corneas, post-euthanasia, were analyzed with Masson's Trichrome and Periodic Acid-Schiff (PAS) histology evaluations. The ultrastructure changes in all corneas were investigated with transmission electron microscopy (TEM). Injury to eye produced clinically relevant corneal haze and neovascularization in dcn−/− and dcn+/+ mice while corneas of uninjured eyes remained clear and avascular. A clinically significant haze and neovascularization appeared in injured dcn−/- corneas compared to the dcn+/+ corneas at day 21 post-injury and not at early tested times. Histological examinations revealed noticeably abnormal morphology and compromised collagen levels in injured dcn−/− corneas compared to the injured/normal dcn+/+ and uninjured dcn−/− corneas. TEM analysis exhibited remarkably uneven collagen fibrils size and distribution in the stroma with asymmetrical organization and loose packing in injured dcn−/− corneas than injured/normal dcn+/+ and uninjured dcn−/− corneas. The minimum and maximum inter-fibril distances were markedly irregular in injured dcn−/− corneas compared to all other corneas. Together, results of clinical, histological, and ultrastructural investigations in a genetic knockout model suggested that decorin influenced stromal fibrillogenesis and transparency in healing cornea.

Evaluation of the Effect of Pomegranate Seed Oil on Healing in a Rat Wound Model With Antioxidant, Vascular, and Histopathological Parameters

The study aimed to evaluate the efficiency of pomegranate (Punica granatum) seed oil in wound healing in excised rats. Sixteen female young Wistar Albino Rats weighing approximately 300 to 320 g were randomly divided into 2 groups as the treatment (=pomegranate seed oil group) and control groups in this experiment. Six different wounds 1 cm apart from the midline and each other were formed with a 6 mm punch biopsy instrument. Three wounds were left open (open wound group) whereas 3 wounds were sutured with 4/0 vicryl (closed wound group). Punica granatum seed oil treatment was administered topically to the treatment group, both to open and closed wounds, once a day for 14 days. Parameters for healing were evaluated. Histopathologic examination was performed for the investigation of inflammation, neovascularization, granulation, and fibroblast generation in addition to serologic (enzyme-linked immunosorbent assay) evaluation of rat malondialchehyche, rat glutathione peroxidase, and rat superoxide dismutase. PeriScan PIM 3 System Laser Doppler Blood Perfusion Imager was used for the calculation of blood perfusion. There was a statistically significant difference between inflammation and neovascularization levels and group type on the 14th day in open wounds(P < .05). On the 21st day, the granulation tissue level in the closed wound group was found to be higher in the pomegranate group (P = 0.000).The results showed that PSE oil is partially effective, although it is not effective in every parameter examined, in the treatment of excised wounds in rats and may be suitable for clinical treatment in humans but large controlled studies are needed.

A novel method for visualizing and tracking endogenous mRNA in a specific cell population in pathological neovascularization

Diabetic retinopathy, retinopathy of prematurity and retinal vein occlusion are potentially blinding conditions largely due to their respective neovascular components. The development of real-time in vivo molecular imaging methods, to assess levels of retinal neovascularization (NV), would greatly benefit patients afflicted with these conditions. mRNA hybridization techniques offer a potential method to image retinal NV. The success of these techniques hinges on the selection of a target mRNA whose tissue levels and spatial expression patterns correlate closely with disease burden. Using a model of oxygen-induced retinopathy (OIR), we previously observed dramatic increases in retinal endoglin that localized to neovascular structures (NV), directly correlating with levels of neovascular pathology. Based on these findings, we have investigated Endoglin mRNA as a potential marker for imaging retinal NV in OIR mice. Also of critical importance, is the application of innovative technologies capable of detecting mRNAs in living systems with high sensitivity and specificity. To detect and visualize endoglin mRNA in OIR mice, we have designed and synthesized a novel imaging probe composed of short-hairpin anti-sense (AS) endoglin RNA coupled to a fluorophore and black hole quencher (AS-Eng shRNA). This assembly allows highly sensitive fluorescence emission upon hybridization of the AS-Eng shRNA to cellular endoglin mRNA. The AS-Eng shRNA is further conjugated to a diacyl-lipid (AS-Eng shRNA–lipid referred to as probe). The lipid moiety binds to serum albumin facilitating enhanced systemic circulation of the probe. OIR mice received intraperitoneal injections of AS-Eng shRNA–lipid. Ex vivo imaging of their retinas revealed specific endoglin mRNA dependent fluorescence superimposed on neovascular structures. Room air mice receiving AS-Eng shRNA–lipid and OIR mice receiving a non-sense control probe showed little fluorescence activity. In addition, we found that cells in neovascular lesions labelled with endoglin mRNA dependent fluorescence, co-labelled with the macrophage/microglia-associated marker IBA1. Others have shown that cells expressing macrophage/microglia markers associate with retinal neovascular structures in proportion to disease burden. Hence we propose that our probe may be used to image and to estimate the levels of retinal neovascular disease in real-time in living systems.

Studies of Superb Microvascular Imaging and Contrast-Enhanced Ultrasonography in the Evaluation of Vascularization in Early Bone Regeneration.

The aim of this study was to investigate value of superb microvascular imaging (SMI) and contrast-enhanced ultrasonography (CEUS) in evaluating the neovascularization of early bone regeneration. Twenty-five Sprague-Dawley male rats were implanted with recombinant human bone morphogenetic protein-2/calcium phosphate cement (rhBMP-2/) in the muscle space of the left hind limb near the femoral head to establish the rat model of intramuscular ectopic osteogenesis. Ultrasonography and pathologic analysis were performed on the 3rd, 7th, 14th, 21st, and 28th days after modeling. Two-dimensional ultrasonography, SMI, and CEUS were used to assess neovascularization and bone formation. Pathologic examination showed that different levels of neovascularization were observed in the graft bone over time after modeling, which increased significantly from the 3rd to 14th day, and then gradually decreased. CEUS and SMI showed no obvious microvessels inside the graft bone on the 3rd day. On the 7th day after modeling, a small number of neovascular vessels were observed around the graft bone. On the 14th day, neovascularization was observed in both the peripheral and inner parts of the graft bone. The number of neovascular vessels inside the graft bone had decreased gradually by the 21st and 28th days. The results of SMI and CEUS indexes showed that the vascular index, peak intensity, enhancement intensity, and enhancement rate first increased and then decreased with time. Their peak points were found on the 14th day. Arrival time, time to peak, and enhancement time decreased gradually over time (P < .05). The combined application of SMI and CEUS may be useful in evaluating the neovascularization of early osteoanagenesis.

Endocan Blockade Suppresses Experimental Ocular Neovascularization in Mice.

Ocular neovascularization (NV) is a pathologic process characterized by the proliferation and infiltration of various types of cells such as RPE, glial, and endothelial cells, which interact with proangiogenic factors and inflammatory cytokines. Endocan is known to be enriched in retinal endothelial tip cells under hypoxia, but the effect of endocan on ocular NV progression is largely unknown. In this study, we investigated the role of endocan in the ocular NV pathologic process and the possible mechanisms involved. In the eyes of mice with oxygen-induced retinopathy (OIR); choroidal NV (CNV); and rhodopsin promoter (rho)/VEGF transgenic mice, endocan expression was assessed by quantitative real-time PCR (RT-PCR) and Western blot. In vivo, a specific functional antibody was used to neutralize endocan and ocular NV levels were evaluated by RT-PCR, Western blot and immunostaining of flat-mounts. In vitro, the effect of endocan on human retinal microvascular endothelial cell (HREC) tube formation was observed using a routine method. Endocan was significantly elevated in these three experimental mice models. Endocan blockade with the neutralizer intravitreal injection not only suppressed the area of retinal, choroidal and subretinal NV, but also resulted in a decrease in several angiogenesis-associated molecules. Recombinant endocan protein (rhEndocan) was found to induce tube formation on HRECs directly. The current data suggest that endocan is a potential therapeutic or an additional target for retinal and subretinal NV diseases.

Boron-Doped Nanocrystalline Diamond Electrodes for Neural Interfaces: In vivo Biocompatibility Evaluation.

Boron-doped nanocrystalline diamond (BDD) electrodes have recently attracted attention as materials for neural electrodes due to their superior physical and electrochemical properties, however their biocompatibility remains largely unexplored. In this work, we aim to investigate the in vivo biocompatibility of BDD electrodes in relation to conventional titanium nitride (TiN) electrodes using a rat subcutaneous implantation model. High quality BDD films were synthesized on electrodes intended for use as an implantable neurostimulation device. After implantation for 2 and 4 weeks, tissue sections adjacent to the electrodes were obtained for histological analysis. Both types of implants were contained in a thin fibrous encapsulation layer, the thickness of which decreased with time. Although the level of neovascularization around the implants was similar, BDD electrodes elicited significantly thinner fibrous capsules and a milder inflammatory reaction at both time points. These results suggest that BDD films may constitute an appropriate material to support stable performance of implantable neural electrodes over time.

A study in the correlation between vascular factors and plaque imaging morphology of coronary borderline lesions in patients with coronary heart disease

Objective To investigate the correlation between the levels of placenta growth factor (PLGF) , soluble angiopoietin receptor-2 (sTie-2) and critical coronary artery plaque imaging morphology of coronary borderline lesions in patients with coronary heart disease (CHD) . Methods In three consecutive years from April 2007 to September 2009, a cohort of 719 patients with borderline coronary lesions with stenosis in three main vessels with lumen diameter reduction varied all the way from more than 20% to less than 70% and with greater than 2.25 mm of the inner diameter were selected in this study from 4 teaching hospitals of tertiary class A in Beijing. These patients fell into three categories: unstable angina pectoris (UAP, n =292) , stable angina pectoris (SAP, n =219) and coronary arteriosclerosis (AS, n =208) . The vessels involved were analyzed using quantitative coronary angiography (QCA) . Plasma levels of PLGF and sTie-2 were measured by using protein chip. The relationship between plasma levels of vascular factors, sTie-2, PLGF and coronary artery plaque imaging morphology among three groups were analyzed. Results (1) Plasma level of PLGF was 80.33 ng/L in the UAP group, which was significantly higher than 54.29 ng/L in the SAP group and 45.16 ng/L in AS group (both P <0.05) . Plasma level of sTie-2 was 1353.06 ng/L in the UAP group, which was significantly higher than 1308.28 ng/L in the AS group (P =0.008) . (2) There was significantly statistical differences in QCA between the SAP group and the UAP group as well as the AS group (both P <0.05) in terms of the minimal lumen diameter, diameter stenosis rate, minimal lumen cross-sectional area and cross-sectional area of stenosis. The plaque area in the UAP group was larger than that in the AS group (P =0.013) . (3) The relationship between vascular factors and plaque imaging morphology was analyzed. There was significantly statistical difference in the involved lesions among the three groups (P <0.01) . (4) There was a positive correlation between plasma level of PLGF and minimal lumen cross-sectional area (r =0.493, P =0.009). Conclusions The plasma levels of PLGF and sTie-2 reflect the level of neo-vascularization in the plaque, and could be taken as predictive factors for potential pathogenesis of coronary plaque. Key words: Coronary heart disease; PLGF; sTie-2; Quantitative coronary angiography

Tachycardia pacing induces myocardial neovascularization and mobilizes circulating endothelial progenitor cells partly via SDF-1 pathway in canines.

Neovascularization plays pivotal role in ischemic heart failure; however, it is unclear in non-ischemic heart failure. Non-ischemic heart failure was induced by chronic rapid right ventricular pacing at 200 beats/min, respectively, for 3 and 6 weeks in 12 dogs. Sham-operation was performed in another 6 dogs as control. Three-week tachycardia pacing could induce mild/moderate heart failure and 6-week pacing could induce severe heart failure. Pan-microvessel density (MVD) was assessed by CD31 and neovascularization density was assessed by CD105. Mean CD31-MVD and CD105-MVD were significantly increased after 3-week pacing. However, CD105-MVD was significantly decreased by 80 % in 6-week pacing group compared with 3-week pacing group, whereas CD31-MVD was only decreased slightly (15 %; P < 0.05). Myocardial proangiogenic factor stromal cell-derived factor 1 (SDF-1), hypoxia-inducible factors 1α (HIF-1α, a transcription factor which could regulate SDF-1 expression), serum SDF-1 levels and circulating EPC mobilization were greatly elevated after 3-week pacing but nearly returned to baseline level after 6-week pacing, which were in accordance with the changes of neovascularization levels assessed by CD105. Angiogenesis and migrating ability of EPCs were enhanced after stimulation of SDF-1, which could be abolished by pretreatment with SDF-1 receptor antagonist AMD3100. In addition, angiogenesis and migrating functions of EPCs were significantly enhanced by the serum from 3-week pacing dogs, but had much weaker response to the serum from 6-week pacing dogs. In conclusion, tachycardia pacing-induced non-ischemic heart failure, promoted myocardial neovascularization and mobilized circulating EPCs, which might be mediated partly through SDF-1 pathway.

Cellular Mechanisms of High Mobility Group 1 (HMGB-1) Protein Action in the Diabetic Retinopathy

Diabetic retinopathy is one of the main microvascular complications of diabetes and remains one of the leading causes of blindness worldwide. Recent studies have revealed an important role of inflammatory and proangiogenic high mobility group 1 (HMGB-1) cytokine in diabetic retinopathy. To elucidate cellular mechanisms of HMGB-1 activity in the retina, we performed this study. The histological features of diabetic retinopathy include loss of blood-vessel pericytes and endothelial cells, as well as abnormal new blood vessel growth. To establish the role of HMGB-1 in vulnerability of endothelial cells and pericytes, cultures of these cells, or co-cultures with glial cells, were treated with HMGB-1 and assessed for survival after 24 hours. The expression levels of the cytokines, chemokines, and cell adhesion molecules in glial and endothelial cells were tested by quantitative RT-PCR to evaluate changes in these cells after HMGB-1 treatment. Animal models of neovascularization were also used to study the role of HMGB-1 in the retina. We report that pericyte death is mediated by HMGB-1-induced cytotoxic activity of glial cells, while HMGB-1 can directly mediate death of endothelial cells. We also found that HMGB-1 affects endothelial cell activity. However, we did not observe a difference in the levels of neovascularization between HMGB-1-treated eyes compared to the control eyes, nor in the levels of proangiogenic cytokine VEGF-A expression between glial cells treated with HMGB-1 and control cells. Our data also indicate that HMGB-1 is not involved in retinal neovascularization in the oxygen-induced retinopathy model. Thus, our data suggest that retinal pericyte and endothelial injury and death in diabetic retinopathy may be due to HMGB-1-induced cytotoxic activity of glial cells as well as the direct effect of HMGB-1 on endothelial cells. At the same time, our findings indicate that HMGB-1 plays an insignificant role in retinal and choroidal neovascularization.

Reduced BDNF attenuates inflammation and angiogenesis to improve survival and cardiac function following myocardial infarction in mice

Brain-derived neurotrophic factor (BDNF) increases in failing hearts, but BDNF roles in cardiac remodeling following myocardial infarction (MI) are unclear. Male BDNF(+/+) [wild-type (WT)] and BDNF(+/-) heterozygous (HET) mice at 6-9 mo of age were subjected to MI and evaluated at days 1, 3, 5, 7, or 28 post-MI. At day 28 post-MI, 76% of HET versus 40% of WT survived, whereas fractional shortening improved and neovascularization levels were reduced in the HET (all, P < 0.05). At day 1, post-MI, matrix metalloproteinase-9, and myeloperoxidase (MPO) increased in WT, but not in HET. Concomitantly, monocyte chemotactic protein-1 and -5 levels increased and vascular endothelial growth factor (VEGF)-A decreased in HET. Neutrophil infiltration peaked at days 1-3 in WT mice, and this increase was blunted in HET. To determine if MPO administration could rescue the HET phenotype, MPO was injected at 3 h post-MI. MPO restored VEGF-A levels without altering matrix metalloproteinase-9 or neutrophil content. In conclusion, reduced BDNF levels modulated the early inflammatory and neovascularization responses, leading to improved survival and reduced cardiac remodeling at day 28 post-MI. Thus reduced BDNF attenuates early inflammation following MI by modulating MPO and angiogenic response through VEGF-A.

Relationship between neovascularization and degenerative changes in herniated lumbar intervertebral discs

Lumbar disc degeneration may be associated with intensity of neovascularization in disc herniations. Our study was designed to evaluate how much the severity of histodegeneration is related to the development of neovascularization and to the level of pleiotrophin in the herniated lumbar discs. Surgically excised lumbar disc specimens were obtained from 29 patients with noncontained (i.e., extruding through the posterior longitudinal ligament) and 21 patients with contained disc herniations. The histodegeneration scores and levels of neovascularization were estimated according to semiquantitative analysis in lumbar disc and endplate samples. Immunohistochemical staining were performed to identify the newly formed blood vessels and to detect the presence of pleiotrophin in the specimens. Higher levels of disc and endplate neovascularity were registered in noncontained herniations. The level of neovascularization was significantly related to the score of histodegeneration in the herniated disc tissues but not in the endplate specimens. Both contained and noncontained herniations had the highest values of histodegeneration in conjunction with the highest level of neovascularization but the relations between neovascularity and degenerative changes remained to be significant only in the group of noncontained herniations. Registration or frequency of pleiotrophin positive cells did not correlate significantly with histodegeneration or level of neovascularization in the disc samples. Severe histodegeneration of the lumbar disc herniations is associated with enhanced neovascularization and potentially also spontaneous regression of the herniated tissue.

Reduced BDNF attenuates inflammation and angiogenesis to improve survival and cardiac function following myocardial infarction in mice

Brain‐derived neurotrophic factor (BDNF) increases in failing hearts, but BDNF roles in cardiac remodeling following myocardial infarction (MI) are unclear. Male BDNF+/+ (wild type, WT) and BDNF+/− heterozygous (HET) mice at 6–9 months of age were subjected to MI and evaluated at day (d) 1, 3, 5, 7, or 28 post‐ MI. At d28 post‐MI, 76% of HET vs. 40% of WT mice survived, while fractional shortening was improved and neovascularization levels were reduced in the HET (all p&lt;0.05). At d1 post‐MI, matrix metalloproteinase (MMP)‐9 and myeloperoxidase (MPO) increased in WT, but not in HET. Concomitantly, monocyte chemotactic protein (MCP)‐1 and ‐5 levels increased and vascular endothelial growth factor (VEGF)‐A decreased in HET. Neutrophil infiltration peaked at d1–3 in WT mice, and this increase was blunted in HET. To determine if MPO administration could rescue the HET phenotype, MPO was injected at 3h post‐MI. MPO restored VEGF‐A levels without altering MMP‐9 or neutrophil content. In conclusion, reduced BDNF levels modulated the early inflammatory and neovascularization responses, leading to improved survival and reduced cardiac remodeling at d28 post‐MI. Thus, reduced BDNF attenuates early inflammation following MI by modulating MPO and angiogenic response through VEGF‐A.Funding support: GVH: NIH‐1K99AT006704–01, YFJ: NIH EB009496 and 1SC2 HL101430, MLL: NIH/NHLBI HHSN 268201000036C (N01‐HV‐00244), R01 HL075360, the Max and Minnie Tomerlin Voelcker Fund, and the Veteran's Administration.

TRAIL-Deficient Mice Exhibit Delayed Regression of Retinal Neovascularization

While it is well established that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in various cell types, the role of TRAIL in regulation of retinal neovascularization (NV) has not been described. Here we determined the role of TRAIL in retinal NV during oxygen-induced retinopathy using TRAIL deficient ((-/-)) mice. TRAIL and its receptor, DR5, were expressed in wild-type retinas at all time points evaluated (postnatal days 12, 17, 21, 24) during oxygen-induced retinopathy and in age-matched room air control animals. Localization of TRAIL(+) cells within the neovascular tufts of hyperoxia- exposed wild-type mice suggested TRAIL plays a role in oxygen-induced retinopathy. Retinal vascular development appeared normal in the TRAIL(-/-) mice, except for a small but significant difference in the capillary-free zone surrounding major arteries. A minimal difference in avascularity was observed at postnatal day 12 in the retinas of TRAIL(-/-) mice after hyperoxia-exposure compared with wild-type mice, suggesting that TRAIL does not play a major role in the vaso-obliterative phase of oxygen-induced retinopathy. However, at the peak of NV, TRAIL(-/-) mice had a significant increase in retinal neovascularization. In addition, when NV naturally regresses in wild-type mice, TRAIL(-/-) mice continued to display significantly high levels of NV. This was attributed to a significant decrease in neovascular tuft cells undergoing apoptosis in TRAIL(-/-) mice. Together, these data strongly suggest that TRAIL plays a role in the control of retinal NV.

The effects of topical tripeptide copper complex and helium‐neon laser on wound healing in rabbits

The aim of this study was to compare the clinical and histopathological effects of tripeptide copper complex (TCC) and two different doses of laser application (helium-neon laser, 1 and 3 J cm(-2)) on wound healing with untreated control wounds. Experimental wounds were created on a total of 24 New Zealand white rabbits and topical TCC or laser was applied for 28 days. The wounds were observed daily, and planimetry was performed on days 7, 14, 21 and 28 to measure the unhealed wound area and percentage of total wound healing. Biopsies were taken weekly to evaluate the inflammatory response and the level of neovascularization. The median time for the first observable granulation tissue was shorter (P < 0.05) in the low and high dose laser groups than in the control group (3 and 2.66 vs. 4.5 days), but was not different between the TCC and control groups (4.16 vs. 4.5 days). Filling of the open wound to skin level with granulation tissue was faster (P < 0.05) in the TCC and high dose laser groups than in the control group (14 and 16 vs. 25 days), but was not different between the low dose laser and control groups (23 vs. 25 days). The average time for healing was shorter (P < 0.05) in the TCC and high dose laser groups (29.8 and 30.2 vs. 34.6 days), but was not different between the low dose laser and control groups (33.8 vs. 34.6 days). Histopathologically, wound healing was characterized by a decrease in the neutrophil counts and an increase in neovascularization. The TCC and high dose laser groups had greater neutrophil and vessel counts than in the control group, suggesting a more beneficial effect for wound healing.

Achilles tendon pain intensity and level of neovascularization in athletes as determined by color Doppler ultrasound

The cause of pain in Achilles tendinopathy is thought to be related to the presence of neovascularization in the tendon as seen on color Doppler ultrasound. Asymptomatic pathology has been observed in patellar tendons of elite athletes. The purpose of this study was to examine the prevalence of Achilles tendon pain and the characteristics of Achilles tendons in a young athletic population. Sixty-four varsity athletes underwent color Doppler ultrasound imaging to determine tendon thickness, presence of degeneration and neovascularization. The presence of swelling and tenderness was determined, and Achilles tendon pain was rated on three visual analogue scales (VAS) (pain during exercise, pain at rest, pain during daily activities) as well as on the VISA-A scale. Tendon symptoms were not related to the presence of neovascularization. There was a low prevalence of Achilles tendinopathy, tenderness, and neovascularization in this population. Neovascularization was seen in both a painful and a non-painful tendon.