Hyaluronan-mediated angiogenesis in vascular disease: uncovering RHAMM and CD44 receptor signaling pathways

The correct formation of new blood vessels from existing vasculature (angiogenesis) is essential for embryogenesis and the effective repair of damaged or wounded tissues. However, excessive and detrimental vascularization also occurs in neoplasia, promoting tumour growth and metastasis, as well as in proliferative diabetic retinopathy and atherosclerosis. Greater understanding of the mechanisms controlling the angiogenic process will allow optimization of wound healing, and provide mechanisms to inhibit vascularization in tumours and other diseases. Evidence supports a cascade of events in which the perturbation of one of the steps is sufficient to significantly inhibit neovascularization. The extracellular macromolecules, notably glycosaminoglycans (GAGs), are important mediators of angiogenesis. Hyaluronan (HA), a large, non-sulphated GAG, was first discovered in the vitreous of the eye [.], and is ubiquitously expressed in the extracellular matrix (ECM) of tissues. Native high molecular weight HA (n-HA) is anti-angiogenic, whereas HA degradation products (o-HA; 3-10 disaccharides) stimulate endothelial cell (EC) proliferation, migration and tube formation following activation of specific HA receptors in particular, CD44 and Receptor for HA-Mediated Motility (RHAMM, CD168). The involvement of HA in the regulation of angiogenesis makes it an attractive therapeutic target. We review the role of o-HA in modulation of angiogenesis during tissue injury, and vascular disease, focusing on receptor-mediated signal transduction pathways that have been evaluated.

Morphine and metabolite behavior after different routes of morphine administration: demonstration of the importance of the active metabolite morphine-6-glucuronide

The pharmacokinetic parameters of morphine, morphine-6-glucuronide, and morphine-3-glucuronide were studied after single-dose morphine administration by five different routes. The quantitative significance of the active metabolite morphine-6-glucuronide was assessed, and the effects of novel dosing forms on morphine metabolism and distribution were examined. After administration of intravenous morphine the morphine-6-glucuronide plasma AUC exceeded that of morphine. After administration of oral morphine very low morphine levels were observed--the morphine-6-glucuronide plasma AUC exceeded that of morphine by a factor of 9:1. Sublingual, buccal, and sustained-release buccal morphine tablet administration resulted in delayed absorption, with attenuation and delay of peak morphine and metabolite levels. Morphine bioavailability and morphine glucuronide production were not altered.

Angiogenic oligosaccharides of hyaluronan induce multiple signaling pathways affecting vascular endothelial cell mitogenic and wound healing responses

Hyaluronan (HA) is a large nonsulfated glycosaminoglycan and an important regulator of angiogenesis, in particular, the growth and migration of vascular endothelial cells. We have identified some of the key intermediates responsible for induction of mitogenesis and wound recovery. Treatment of bovine aortic endothelial cells with oligosaccharides of hyaluronan (o-HA) resulted in rapid tyrosine phosphorylation and plasma membrane translocation of phospholipase Cgamma1 (PLCgamma1). Cytoplasmic loading with inhibitory antibodies to PLCgamma1, Gbeta, and Galpha(i/o/t/z) inhibited activation of extracellular-regulated kinase 1/2 (ERK1/2). Treatment with the Galpha(i/o) inhibitor, pertussis toxin, reduced o-HA-induced PLCgamma1 tyrosine phosphorylation, protein kinase C (PKC) alpha and beta1/2 membrane translocation, ERK1/2 activation, mitogenesis, and wound recovery, suggesting a mechanism for o-HA-induced angiogenesis through G-proteins, PLCgamma1, and PKC. In particular, we demonstrated a possible role for PKCalpha in mitogenesis and PKCbeta1/2 in wound recovery. Using antisense oligonucleotides and the Ras farnesylation inhibitor FTI-277, we showed that o-HA-induced bovine aortic endothelial cell proliferation, wound recovery, and ERK1/2 activation were also partially dependent on Ras activation, and that o-HA-stimulated tyrosine phosphorylation of the adapter protein Shc, as well as its association with Sos1. Binding of Src to Shc was required for its activation and for Ras-dependent activation of ERK1/2, cell proliferation, and wound recovery. Neither Src nor Ras activation was inhibited by pertussis toxin, suggesting that their activation was independent of heterotrimeric G-proteins. However, the specific Src kinase inhibitor PP2 inhibited Gbeta subunit co-precipitation with PLCgamma1, suggesting a possible role for Src in activation of PLCgamma1 and interaction between two distinct o-HA-induced signaling pathways.

The analgesic activity of morphine-6-glucuronide

1. The pharmacokinetics, cardio-respiratory effects and analgesic effects of intravenous morphine-6-glucuronide were studied in 20 cancer patients with pain. Four different dose levels (0.5, 1, 2, and 4 mg 70 kg-1) were studied. Plasma concentrations of morphine-6-glucuronide were measured for 12 h after dosing. Pulse rate, respiratory rate and blood pressure were monitored, and pain relief was measured using two rating scales and a visual analogue scale. 2. The mean elimination half-life (+/- s.d.) of morphine-6-glucuronide was 3.2 +/- 1.6 h. The mean AUC standardised to a dose of 1 mg 70 kg-1 was 390 +/- 263 nmol l-1 h. Mean morphine-6-glucuronide clearance was 96 +/- 38 ml min-1. There was a direct relationship between morphine-6-glucuronide plasma clearance and calculated creatinine clearance (r = 0.81, P less than 0.001). 38 +/- 22% of the dose of morphine-6-glucuronide was recovered unchanged in the urine in 24 h. No morphine or morphine-3-glucuronide was detected in the plasma or urine of any patient after morphine-6-glucuronide treatment. 3. Morphine-6-glucuronide exerted a useful analgesic effect in 17/19 assessable patients for periods ranging between 2 and 24 h. No correlation was observed between dose or plasma morphine-6-glucuronide concentrations, and duration or degree of analgesia. No clinically significant changes in cardio-respiratory parameters were observed. No patients reported sedation or euphoria. Nausea and vomiting were notably absent in all cases. 4. Morphine-6-glucuronide is an effective and well-tolerated analgesic. It is likely that the majority of the therapeutic benefit of morphine is mediated by morphine-6-glucuronide.(ABSTRACT TRUNCATED AT 250 WORDS)

C-Reactive Protein in Atherothrombosis and Angiogenesis

C-reactive protein (CRP) is a short pentraxin mainly found as a pentamer in the circulation, or as non-soluble monomers CRP (mCRP) in tissues, exerting different functions. This review is focused on discussing the role of CRP in cardiovascular disease, including recent advances on the implication of CRP and its forms specifically on the pathogenesis of atherothrombosis and angiogenesis. Besides its role in the humoral innate immune response, CRP contributes to cardiovascular disease progression by recognizing and binding multiple intrinsic ligands. mCRP is not present in the healthy vessel wall but it becomes detectable in the early stages of atherogenesis and accumulates during the progression of atherosclerosis. CRP inhibits endothelial nitric oxide production and contributes to plaque instability by increasing endothelial cell adhesion molecules expression, by promoting monocyte recruitment into the atheromatous plaque and by enzymatically binding to modified low-density lipoprotein. CRP also contributes to thrombosis, but depending on its form it elicits different actions. Pentameric CRP has no involvement in thrombogenesis, whereas mCRP induces platelet activation and thrombus growth. In addition, mCRP has apparently contradictory pro-angiogenic and anti-angiogenic effects determining tissue remodeling in the atherosclerotic plaque and in infarcted tissues. Overall, CRP contributes to cardiovascular disease by several mechanisms that deserve an in-depth analysis.

Serial measurement of vascular endothelial growth factor and transforming growth factor-beta1 in serum of patients with acute ischemic stroke

BACKGROUND AND PURPOSE

Both vascular endothelial growth factor (VEGF) and transforming growth factor-beta1 (TGF-beta1) are expressed in higher than normal concentrations in the penumbra of patients after ischemic stroke. Because both cytokines are central to the processes of angiogenesis, tissue inflammation, and fibrosis, we performed serial measurements of these cytokines in patients with cerebral infarction and determined their relationship to stroke etiology and volume.

METHODS

We serially (at days 0, 1, 3, 7, and 14) measured the serum levels of VEGF and active TGF-beta1 in 29 patients with acute ischemic stroke. Age-matched healthy subjects (n=26) were used as controls.

RESULTS

Expression of VEGF was significantly increased in the majority of patients after acute stroke at each of the time points compared with normal controls. Highest expression occurred at day 7 (588+/-121 pg/mL; P=0.005), and it remained significantly elevated at 14 days after stroke. Expression of VEGF correlated with infarct volume, clinical disability (Scandinavian Stroke Scale), and peripheral leukocytosis and was significantly higher in patients with atherothrombotic large-vessel disease and ischemic heart disease (P<0.05 in all cases). In contrast, expression of active TGF-beta1 was not significantly different from control patients at any of the measured time points. When the mean concentration of TGF-beta1 from each patient (pooled time points) was compared with the control mean, a significant increase was found in only 2 patients, whereas levels decreased in 12 patients (P<0.05). There was no correlation between circulating active TGF-beta1 and VEGF expression, leukocytosis, stroke subtype, or patient disability as assessed by Scandinavian Stroke Scale score.

CONCLUSIONS

VEGF but not TGF-beta1 showed a dramatic increase in serum of stroke patients. Correlation between stroke severity and VEGF concentration suggests it could be involved in the subsequent repair processes resulting in partial recovery after stroke. Correlation between VEGF expression and peripheral leukocytosis suggests that these changes may also reflect the immunologic status of the patient. VEGF may play an important role in the pathophysiology of acute ischemic stroke and could be of value in future treatment strategies.

A putative role for platelet-derived growth factor in angiogenesis and neuroprotection after ischemic stroke in humans

BACKGROUND AND PURPOSE

Growth factors control two important processes in infarcted tissue, ie, angiogenesis and gliosis. We recently reported that transforming growth factor-beta1 (TGF-beta1) might be involved in angiogenesis after ischemic stroke in humans; here we present data of an extensive study on platelet-derived growth factor (PDGF) and its receptors.

METHODS

We studied brain samples from patients who suffered from ischemic stroke for the expression of mRNA encoding PDGF-A, PDGF-B, and PDGF receptors (PDGF-R). Proteins were examined by Western blotting and immunohistochemistry using the antibodies to PDGF-AB, PDGF-BB, PDGF-R alpha, and PDGF-R beta.

RESULTS

At the mRNA level, PDGF-A and PDGF-B were expressed mainly in neurons in penumbra. PDGF-R mRNA was strongly expressed in some astrocytes but mainly in type III/IV neurons in infarct and penumbra. The least expression was seen in the contralateral hemisphere (P<.001). In contrast, both PDGF-AB and PDGF-BB immunoreactive products were present in most cell types: PDGF-R alpha and PDGF-R beta mainly on neurons, and PDGF-R beta on some endothelial cells, with less staining of all the isoforms in the contralateral hemisphere. On Western blots, PDGF-AB and -BB were expressed more within white matter than gray matter of infarct/penumbra, whereas both isoforms of receptor were expressed mainly in gray matter compared with contralateral hemisphere. There was no or very weak expression of the receptor in white matter.

CONCLUSIONS

PDGF proteins are highly expressed in white matter, suggesting that PDGF may exert its function in white matter participating either in regeneration of damaged axons or in glial scar formation. PDGF-BB and its receptor expressed on microvessel endothelial cells might be involved in angiogenesis after stroke. Thus, PDGF is likely to be angiogenic and neuroprotective in stroke.

Changes in hyaluronan production and metabolism following ischaemic stroke in man

The extent of recovery from stroke is dependent on the survival of neurons, particularly in peri-infarcted regions. Angiogenesis is critical for the development of new microvessels and leads to re-formation of collateral circulation, reperfusion and better recovery. Hyaluronan (HA) is an important component of the brain extracellular matrix and a regulator of cellular differentiation, migration, proliferation and angiogenesis. We have found that the production of total HA and low molecular mass 3-10 disaccharides of HA (o-HA) was increased in post-mortem tissue and in the serum of patients 1, 3, 7 and 14 days (peaking at 7 days) after ischaemic stroke. Hyaluronidase activity was also increased in serum samples (peaking after 3 days), which might explain the subsequent increase in o-HA. Affinity-histochemical staining was performed using a HA-specific biotinylated binding protein, and it showed enhanced deposition of HA in blood vessels and intracellularly as well as in the nuclei of peri-infarcted neurons. Western blotting and immunohistochemistry demonstrated upregulation of HA synthases (HAS1 and 2) and hyaluronidases (HYAL1 and 2) in inflammatory cells from both stroke and peri-infarcted regions of the brain. HYAL1 was upregulated in microvesssels and intracellularly in neurons, whilst HAS2 became translocated into the nuclei of neurons in peri-infarcted areas. Receptor for HA-mediated motility was observed intracellularly and in the nuclei of neurons, in the tunica media of larger blood vessels and in the endothelial cells of microvessels in stroke-affected tissue, whilst expression of other receptors for HA, CD44 and tumour necrosis factor-stimulated gene 6 (TSG-6) were mainly increased in infiltrating mononuclear cells from inflammatory regions. The data presented here demonstrate that HA breakdown is a feature of the acute stage of stroke injury. Increased o-HA production soon after stroke may be detrimental through enhancement of the inflammatory response, whilst activation of HA and/or o-HA-induced cellular signalling pathways in neurons and microvessels may impact on the remodelling process by stimulating angiogenesis and revascularization, as well as the survival of susceptible neurons.

Pax genes in embryogenesis and oncogenesis

The paired box genes are a family of nine developmental control genes, which in human beings (PAX) and mice (Pax) encode nuclear transcription factors. The temporal and spatial expressions of these highly conserved genes are tightly regulated during foetal development including organogenesis. PAY/Paxgenes are switched off during the terminal differentiation of most structures. Specific mutations within a number of PAX/Pax genes lead to developmental abnormalities in both human beings and mice. Mutation in PAX3 causes Waardenburg syndrome, and craniofacial-deafness-hand syndrome. The Splotch phenotype in mouse exhibits defects in neural crest derivatives such as, pigment cells, sympathetic ganglia and cardiac neural crest-derived structures. The PAX family also plays key roles in several human malignancies. In particular, PAX3 is involved in rhabdomyosarcoma and tumours of neural crest origin, including melanoma and neuroblastoma. This review critically evaluates the roles of PAX/Pax in oncogenesis. It especially highlights recent advances in knowledge of how their genetic alterations directly interfere in the transcriptional networks that regulate cell differentiation, proliferation, migration and survival and may contribute to oncogenesis.

The pharmacokinetics of morphine and morphine glucuronides in kidney failure

The pharmacokinetics of morphine and its glucuronide metabolites were investigated in three groups of patients with kidney failure (nondialyzed, receiving dialysis, and transplantation) and compared with a group of normal healthy volunteers. Patients in all three renal groups were undergoing surgical procedures (nondialyzed group undergoing arteriovenous fistula formation, dialysis group undergoing placement of a peritoneal dialysis catheter, and the transplant group undergoing live donor kidney transplant). A sensitive, specific high-performance liquid chromatographic assay was used to quantitate morphine, morphine-3-glucuronide, and morphine-6-glucuronide. Patients with kidney failure had a significantly increased morphine area under the curve (AUC) compared with control subjects. There was also an increase in the metabolites morphine-3-glucuronide and morphine-6-glucuronide that was severalfold greater than the increase in morphine AUC. This metabolite accumulation was reversed by kidney transplantation, providing an elegant confirmation on the role of the kidney in morphine pharmacology.

Can angiogenesis be exploited to improve stroke outcome? Mechanisms and therapeutic potential

Recent developments in our understanding of the pathophysiological events that follow acute ischaemic stroke suggest an important role for angiogenesis which, through new blood vessel formation, results in improved collateral circulation and may impact on the medium-to-long term recovery of patients. Future treatment regimens may focus on optimization of this process in the ischaemic boundary zones or 'penumbra' region adjacent to the infarct, where partially affected neurons exposed to intermediate perfusion levels have the capability of survival if perfusion is maintained or normalized. In this review, we present evidence that angiogenesis is a key feature of ischaemic stroke recovery and neuronal post-stroke re-organization, examine the signalling mechanisms through which it occurs, and describe the therapeutic potential of treatments aimed at stimulating revascularization and neuroprotection after stroke.

Randomized trial of dose-intensity with single-agent carboplatin in patients with epithelial ovarian cancer. London Gynaecological Oncology Group

PURPOSE

We have examined the role of an increase in cisplatin dose-intensity in patients with advanced epithelial ovarian cancer by means of single-agent carboplatin therapy.

PATIENTS AND METHODS

Two hundred twenty-seven patients were randomized to treatment and eligible for analysis. The dose of carboplatin was calculated according to the Calvert formula. One hundred seventeen patients received carboplatin at an area under the concentration time curve (AUC) of 6 for six courses, administered every 28 days, and 110 patients received carboplatin at an AUC of 12 for four courses, administered every 28 days. Patients were eligible provided they had not received prior chemotherapy or radiotherapy and had International Federation of Gynecology and Obstetrics stages II to IV or relapsed stage I epithelial ovarian cancer.

RESULTS

The planned total-dose increase was 33% for the patients treated with carboplatin AUC 12, but the received percentage total-dose increase was 20%. There were no differences in progression-free or overall survival between the two treatment arms; the overall survival rate at 5 years was 31% and 34% of patients treated at AUCs 6 and 12, respectively. There was significantly more toxicity associated with carboplatin AUC 12, which resulted in more treatment delays and/or dose reductions (52% v 18%; P < .001).

CONCLUSION

We have shown that carboplatin can be delivered at an AUC of 12 for four courses without granulocyte colony-stimulating factor support, although significant hematologic toxicity occurs. Nonhematologic toxicities were not clinically significant. Carboplatin offers an opportunity to intensify cisplatin therapy, but a greater than two-fold increase in dose-intensity probably needs to be achieved before significant effects on survival will be produced and hematologic support will be required.

Volunteers or victims: patients' views of randomised cancer clinical trials

Randomised clinical trials are essential for the objective evaluation of different treatment strategies in cancer. However, in the field of oncology, very few of the eligible patients are entered into trials, and most treatments have only been tested on a small percentage of patients. For doctors, a major deterrent to participating in trials is the lack of resources--particularly time, but often also the local facilities. This report suggests that patients themselves are willing to take part in clinical research, and are attracted by being treated by a doctor with a specialist interest in the disease and encouraged by the possibility that their progress will be monitored closely. With the recent NHS changes, it is timely for the Department of Health and other national health departments to consider carefully what can be done to ensure that no new treatments are adopted without effective evaluation. This will require departments of health to identify and implement ways to facilitate accrual of appropriate numbers of patients onto research protocols (whether non-randomised phase I or phase II studies or large, multicentre phase III trials) over short time periods.

Monomeric C-reactive protein--a key molecule driving development of Alzheimer's disease associated with brain ischaemia?

Alzheimer’s disease (AD) increases dramatically in patients with ischaemic stroke. Monomeric C-reactive protein (mCRP) appears in the ECM of ischaemic tissue after stroke, associating with microvasculature, neurons and AD-plaques, Aβ, also, being able to dissociate native-CRP into inflammatory, mCRP in vivo. Here, mCRP injected into the hippocampal region of mice was retained within the retrosplenial tract of the dorsal 3rd ventrical and surrounding major vessels. Mice developed behavioural/cognitive deficits within 1 month, concomitant with mCRP staining within abnormal looking neurons expressing p-tau and in beta-amyloid 1-42-plaque positive regions. mCRP co-localised with CD105 in microvessels suggesting angiogenesis. Phospho-arrays/Western blotting identified signalling activation in endothelial cells and neurons through p-IRS-1, p-Tau and p-ERK1/2-which was blocked following pre-incubation with mCRP-antibody. mCRP increased vascular monolayer permeability and gap junctions, increased NCAM expression and produced haemorrhagic angiogenesis in mouse matrigel implants. mCRP induced tau244–372 aggregation and assembly in vitro. IHC study of human AD/stroke patients revealed co-localization of mCRP with Aβ plaques, tau-like fibrils and IRS-1/P-Tau positive neurons and high mCRP-levels spreading from infarcted core regions matched reduced expression of Aβ/Tau. mCRP may be responsible for promoting dementia after ischaemia and mCRP clearance could inform therapeutic avenues to reduce the risk of future dementia.

Vascular MMP-9/TIMP-2 and neuronal MMP-10 up-regulation in human brain after stroke: a combined laser microdissection and protein array study

Matrix Metalloproteinases (MMPs) play an important role in brain injury after ischemic stroke. In the present study, we aimed to assess the global expression of MMP-Family proteins in the human brain after stroke by using a combination of Searchlight Protein Array and Laser Microdissection to determine their cellular origin. This study demonstrated that MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, MMP-10, MMP-13, and TIMP-1 were upregulated in the infarcted tissue compared to healthy control areas. Using laser microdissection we obtained specific neuronal and vascular populations from both infarcted and control areas. From these fractions, we showed that MMP-9 and TIMP-2 were highly produced in brain microvessels while MMP-10 was notably increased in neurons of the ischemic brain but not in healthy areas. These findings demonstrate a selective cell-dependent MMP secretion, opening the possibility of selectively targeting specific MMPs for neuroprotection or vasculoprotection following stroke.

Treatment of nondysgerminomatous ovarian germ cell tumors: an analysis of 69 cases

BACKGROUND

Combination chemotherapy has dramatically improved the prognosis of patients with nondysgerminomatous ovarian germ cell tumors (NDOGCT). However, guidelines are needed for the identification of patients at risk of relapse.

METHODS

The authors performed a retrospective analysis of women with NDOGCT managed during the period 1970-1994 at the Royal Marsden Hospital and other hospitals of the London Gynaecological Oncology Group.

RESULTS

Sixty-nine women were included; their median follow-up was 5.7 years (minimum, 12 months). The median age was 21 years (range, 4-44 years), with a histology of immature teratoma (IT) for 17 patients, endodermal sinus tumor (EST) for 20 patients, and mixed tumors for 32 patients. Thirty-five patients (51%) had Stage I disease. Nine patients with Stage I tumors were observed without further therapy (six with IT and three with mixed tumors), and one relapsed. Seven patients received non-platinum-based chemotherapy, and four relapsed. A total of 52 patients were treated with platinum-based chemotherapy, with relapse free and overall survival rates of 87% (95% confidence interval [CI], 73-93%) and 84% (95% CI, 70-91%), respectively. Of these patients, relapse was seen in 0 of 9 IT patients, 1 of 25 patients with mixed tumors, and 6 of 18 EST patients. With alpha-fetoprotein (AFP) > 1000 kU/L, relapse was seen in 6 of 18 patients compared with 1 of 33 relapses with lower AFP levels. In multivariate analysis, including all patients who received chemotherapy, AFP >1000 kU/L (P = 0.001) and non-platinum-based chemotherapy (P = 0.005) were associated with relapse. When only patients given platinum-based treatment were considered, EST histology (P = 0.003) and AFP >1000 kU/L (P = 0.003) were associated with relapse in univariate analysis; however, these factors were linked. No malignant tumor was found at second-look surgery performed on 24 patients. Of 26 women assessable for fertility, 24 subsequently recommenced regular menstrual function, and 11 patients had pregnancies.

CONCLUSIONS

Platinum-based chemotherapy has been confirmed to be effective in the management of patients with NDOGCT. Relapses were principally seen among patients with AFP >1000 kU/L or pure EST histology. Efforts to improve outcome need to focus on patients with EST, whereas less intensive management strategies may be appropriate for some patients with IT.

Therapeutic applications of hyaluronan

Hyaluronan (HA), a multifunctional, high molecular weight glycosaminoglycan, is a component of the majority of extracellular matrices. HA is synthesised in a unique manner by a family of hyaluronan synthases, degraded by hyaluronidases and exerts a biological effect by binding to families of cellular receptors, the hyaladhedrins. Receptor binding activates signal pathways in endothelial cells leading to proliferation, migration and differentiation collectively termed angiogenesis. HA and associated enzymes are implicated in the aetiology of cardiovascular disease and cancer and manipulation of HA expression offers a therapeutic target. HA microspheres have been developed as drug delivery agents to deliver HA to sites of disease and also in diagnosis. In this review we discuss some of the recent therapeutic applications of hyaluronan in tissue repair, as a drug delivery system and the synthesis, application and delivery of hyaluronan nanoparticles to target drugs to sites of disease.

Monomeric C-Reactive Protein and Cerebral Hemorrhage: From Bench to Bedside

C-reactive protein (CRP) is an important mediator and a hallmark of the acute-phase response to inflammation. High-sensitivity assays that accurately measure levels of CRP have been recommended for use in risk assessment in ischemic stroke patients. Elevation of CRP during the acute-phase response in intracerebral hemorrhage (ICH) is also associated with the outcomes such as death and vascular complications. However, no association has been found with the increased risk of ICH. The aim of this review is to synthesize the published literature on the associations of CRP with acute ICH both as a risk biomarker and predictor of short- and long-term outcomes as well as its role as a pathogenic determinant. We believe before any clinical utility, a critical appraisal of the strengths and deficiencies of the accumulated evidence is required both to evaluate the current state of knowledge and to improve the design of future clinical studies.

Bisphosphonate-related osteonecrosis of jaw (BRONJ): diagnostic criteria and possible pathogenic mechanisms of an unexpected anti-angiogenic side effect

Recently, bisphosphonates (BPs) have been widely used in medical practice as anti-resorptive agents owing to their anti-osteoclatic action. In addition, these compounds are also used for their analgesic action and their potential anti-tumour effect. Patients treated with BPs may subsequently develop osteonecrosis of the jaw or maxillary bone after minor local trauma including dental work, recently labelled as bisphosphonate osteonecrosis of jaw (BRONJ). However, the etiopathogenic mechanisms of this pathological condition are poorly understood. Although, several pathways have been proposed for BRONJ occurrence, no single model can explain all morphological changes observed at the macro- and microscopic level. Recent research suggests that BPs may promote an anti-angiogenic effect which contributes directly to the clinical features associated with BRONJ. Remarkably, the anti-angiogenic effect promoting BRONJ might be in keeping with the anti-neoplastic action of BPs. The current review, presents clinical diagnostic criteria. In addition, based on our own experience we describe the histopathological criteria for diagnosis of BRONJ and the possible pathways which may lead to this frustrating pathological condition.

Effect of glycation on basic fibroblast growth factor induced angiogenesis and activation of associated signal transduction pathways in vascular endothelial cells: possible relevance to wound healing in diabetes

Ineffectual wound healing in hyperglycaemic patients suffering from diabetes mellitus is characterised by a reduction in capillary reformation (angiogenesis). Basic fibroblast growth factor (FGF-2) is secreted by fibroblasts, macrophages and in particular endothelial cells (EC) in response to tissue injury and is important in promotion of neovascularisation. Recently, glycation of FGF-2 has been shown to significantly reduce its activity in vitro. We have examined the kinetics of FGF-2 glycation and compared its ability with that of native FGF-2 to activate mitogenesis, capillary formation and associated signal transduction in bovine aortic EC (BAEC). FGF-2 was exposed to 0.25 M glucose-6-phosphate (G-6-P) for 24-72 h and the degree of glycation determined by matrix assisted laser desorption ionisation mass spectrometry. Native FGF-2 was heterogeneous with Mw in the range 15,153.6-17,903 Da. After 24 h incubation with G-6-P there was evidence of glycation, and the mass increase corresponded to addition of 2.7 mol of G-6-P residues; after 48 h, 4 mol sugar was added and this increased to 8.7 after 72 h. Dimerisation of FGF-2 was observed after 72 h of treatment. Induction of mitogenesis in BAEC was significantly reduced by 25%-40% after treatment for 48-96 h with glycated (24 h) FGF-2 (gFGF-2; 100 pg/ml-5 ng/ml; P < 0.05), whilst capillary tubule formation was significantly reduced by between 60% and 90% (100 pg/ml-1 ng/ml; P < 0.05) after 5 days compared to native FGF-2. Subsequent investigation of the signal transduction molecules associated with mitogenesis showed a reduction in FGF-2 induced tyrosine phosphorylated proteins of approximate Mw 20-150 kDa between 10 min and 24 h, in particular, mitogen activated protein kinase (MAPK)/early response kinase (ERK-1, ERK-2), after glycation. To determine the reason for reduced angiogenic activity of gFGF-2, we compared its binding characteristics to that of native FGF-2. Total binding of gFGF-2 to the cell surface was significantly reduced in BAEC analysed by FACS compared to native FGF-2 (P < 0.05). Further investigation using 125I-labelled differentially washed samples, demonstrated a significant reduction in gFGF-2 binding to the high affinity tyrosine kinase receptor (46%) compared to native FGF-2. In summary, glycation of FGF-2 in vitro occurs rapidly within 24 h in the presence of elevated levels of G-6-P. Glycation caused a significant reduction in the ability of FGF-2 to bind to the tyrosine kinase receptor and activate signal transduction pathways responsible for both mitogenesis and capillary formation in BAEC. These results could help to explain the mechanism behind impaired wound healing in patients with diabetes mellitus.

Endogenous Expression of C-Reactive Protein Is Increased in Active (Ulcerated Noncomplicated) Human Carotid Artery Plaques

Background and Purpose— There is growing evidence suggesting that C-reactive protein (CRP) is an effecter molecule able to induce and promote atherothrombosis. The presence of CRP in atherosclerotic plaques may reflect local production or infiltration from circulating CRP increased in general inflammatory responses. Our aim was to analyze the presence of CRP in human advanced carotid artery plaques with differential anatomo-pathological characteristics and to assess local expression of CRP and other proinflammatory genes in these lesions.

Methods— Human carotid artery specimens from 38 patients undergoing scheduled endarterectomy were classified into 3 groups: ulcerated (noncomplicated) (UNC, n=19), fibrous (F, n=12) and ulcerated (complicated/hemorrhagic) plaques (UC, n=7). The presence of CRP was evaluated by immunohistochemistry, and plasma samples were screened for circulating high-sensitivity C-reactive protein. TaqMan Low-density Arrays were used for study of genes related to inflammation (CRP, interleukin-6, macrophage colony-stimulating factor-1, monocyte chemotactic protein-1, cyclooxygenase-2).

Results— CRP mRNA levels were predominantly detected in UNC-high risk plaques but not in UC ( P =0.001). UNC also exhibit the highest expression levels of other genes involved in the inflammatory responses: cyclooxygenase-2 ( P <0.005 versus F and versus UC), IL-6 ( P <0.005 versus F and versus UC) and monocyte chemoattractant protein-1 ( P <0.01 versus F and versus UC). Plaque CRP mRNA levels correlated with immunohistochemical findings but were independent of plasma high-sensitivity CRP. In UNC plaques endothelial cells and inflammatory cells were strongly positive for CRP around areas of newly formed microvessels.

Conclusions— In human high-risk carotid artery plaques (UNC) CRP expression reflects an active proinflammatory stage. Local synthesis of CRP could be involved in plaque neovascularization and increased risk of hemorrhagic transformation.

Activation of MAP kinase (ERK-1/ERK-2), tyrosine kinase and VEGF in the human brain following acute ischaemic stroke

We examined expression of vascular endothelial growth factor (VEGF), phosphorylation of mitogen activated protein kinase (MAP) kinase (ERK1 and ERK2) and tyrosine phosphorylation in 19 patients (aged 58-90 years; mean 75) who died 1-44 days after acute ischaemic stroke. In the grey matter penumbra, 13 of 19 patients showed an increase in MAP kinase tyrosine phosphorylation (ERK1; 2.0- to 8-fold, ERK2; 2.2- to 11-fold) compared with normal contralateral tissue. In almost all cases, ERK-2 phosphorylation was higher than ERK1. Of these 13 patients, 11 also showed a general increase in tyrosine kinase phosphorylation, and eight expressed increased levels of VEGF protein (2.5- to 5-fold). In tissue examined directly from the infarct core, activation of the above proteins was not observed in the, majority of patients. In the white matter, seven of 19 patients (penumbra), and nine of 19 patients (stroke) had an increase in MAP kinase tyrosine phosphorylation (ERK1; 2.0- to 4.6-fold and ERK-2; 2.3- to 5.4-fold respectively) compared with normal contralateral tissue. There was no relationship between activation of MAP kinase and expression of VEGF. Examination of phosphorylated MAP kinase by immunohistochemistry revealed an increase in immunoreactivity in neurones, astroglial cells, reactive microglia and endothelial cells in areas surrounding infarcts, especially in areas with the highest density of microvessels. In conclusion, chronic activation of tyrosine phosphorylated events, in particular redistribution and phosphorylation of MAP kinase (ERK1/ERK2) occurs consistently in the grey matter penumbra of brain tissue following ischaemic stroke, and may be associated with increase in expression of VEGF. These signal transduction events could be important determinants of the extent of neuronal survival and/or angiogenic activity in the recovering brain tissue.

Isolation and expansion of human and mouse brain microvascular endothelial cells

Brain microvascular endothelial cells (BMVECs) have an important role in the constitution of the blood-brain barrier (BBB). The BBB is involved in the disease processes of a number of neurological disorders in which its permeability increases. Isolation of BMVECs could elucidate the mechanism involved in these processes. This protocol describes how to isolate and expand human and mouse BMVECs. The procedure covers brain-tissue dissociation, digestion and cell selection. Cells are selected on the basis of time-responsive differential adhesiveness to a collagen type I-precoated surface. The protocol also describes immunophenotypic characterization, cord formation and functional assays to confirm that these cells in endothelial proliferation medium (EndoPM) have an endothelial origin. The entire technique requires ∼7 h of active time. Endothelial cell clusters are readily visible after 48 h, and expansion of BMVECs occurs over the course of ∼60 d.