Quality control in treating patients with patent foramen ovale: 7-year-experience of the Heart and Brain team of the Careggi University Hospital.

BACKGROUND: The right comprehension of ischemic stroke pathogenesis guarantees the best prevention therapy. The term "patent foramen ovale (PFO) related stroke" has been proposed for those events where PFO is supposed to be pathogenetic, but their definition is challenging. A multidisciplinary evaluation in a "Heart & Brain" team (HBteam) including stroke neurologists and interventional cardiologists was therefore highly recommended in the recent guidelines of secondary stroke prevention. OBJECTIVE: We aimed at describing the organization of the HBteam of Careggi-University-Hospital of Florence (Italy), and the results of the first seven years of activity. METHODS: In 2016 Interventional Cardiologists and Stroke Neurologists set up an outpatient clinic for the joined evaluation of patients with PFO and other cardio/neurological conditions. A specific diagnostic-therapeutic hospital plan was produced for PFO patients. Patient empowerment was guaranteed by a hospital explicative webpage, a booklet regarding risks/benefits of PFO closure and a 3D heartmodel to simulate the intervention. Data were collected in a dedicated registry. RESULTS: We evaluated 594 patients for PFO, 40 for left atrial appendage closure and 38 for other conditions. In 20% of PFO-patients, HBteam diagnosis was discordant from that of referring physicians, 14% were stroke misdiagnoses. We advised against closure in 53% of patients. At follow-up 94% of closed patients had no/minimum residual shunt; 3 patients had a cerebral ischemic event. CONCLUSIONS: A dedicated HBteam represents a unique opportunity to share decisions with patients after a thorough empowerment process. The joining of cardioneurological skills allows a better classification of PFO-patients, reducing futile interventions.

Pregnancy in multiple sclerosis women with relapses in the year before conception increases the risk of long-term disability worsening.

BACKGROUND: The influence of pregnancy on long-term disability in multiple sclerosis (MS) is still controversial. OBJECTIVE: To assess the risk of long-term disability worsening after pregnancy in MS women as compared with a propensity-score (PS) matched group of MS women without pregnancy. METHODS: In the setting of the Italian Pregnancy Dataset, MS patients with (pregnancy group (PG)) and without pregnancy (control group (CG)) were recruited. Time to disability worsening on the Expanded Disability Status Scale (EDSS) was assessed through a multivariable Cox regression model. RESULTS: The PS-matching retained 230 PG and 102 CG patients. After a follow-up of 6.5 +/- 3.1 years, disability worsening occurred in 87 (26.2%) women. In the multivariable analysis, disability worsening was associated with pregnancy in women with relapses in the year before conception (adjusted hazard ratio (aHR) = 1.74; 95% confidence interval (CI) 1.06-2.84; p = 0.027), higher EDSS (aHR = 1.39; 95% CI 1.12-1.74; p = 0.003), younger age (aHR = 0.95; 95% CI 0.91-0.99; p = 0.022) and shorter DMD exposure over the follow-up (p < 0.008). CONCLUSION: Pregnancy in MS women with relapses in the year before conception increases the risk of long-term disability worsening. Our findings underscore the importance of counselling in MS women facing a pregnancy that should be planned after a period of clinical stability, favouring treatment optimization in patients with recent disease activity.

Translational Stroke Research Review: Using the Mouse to Model Human Futile Recanalization and Reperfusion Injury in Ischemic Brain Tissue.

The approach to reperfusion therapies in stroke patients is rapidly evolving, but there is still no explanation why a substantial proportion of patients have a poor clinical prognosis despite successful flow restoration. This issue of futile recanalization is explained here by three clinical cases, which, despite complete recanalization, have very different outcomes. Preclinical research is particularly suited to characterize the highly dynamic changes in acute ischemic stroke and identify potential treatment targets useful for clinical translation. This review surveys the efforts taken so far to achieve mouse models capable of investigating the neurovascular underpinnings of futile recanalization. We highlight the translational potential of targeting tissue reperfusion in fully recanalized mouse models and of investigating the underlying pathophysiological mechanisms from subcellular to tissue scale. We suggest that stroke preclinical research should increasingly drive forward a continuous and circular dialogue with clinical research. When the preclinical and the clinical stroke research are consistent, translational success will follow.

Efficacy and Safety of the Association of Nimodipine and Choline Alphoscerate in the Treatment of Cognitive Impairment in Patients with Cerebral Small Vessel Disease. The CONIVaD Trial.

BACKGROUND: No approved treatment is available for patients with vascular cognitive impairment (VCI) due to cerebral small vessel disease (SVD). OBJECTIVE: The CONIVaD (Choline Alphoscerate and Nimodipine in Vascular Dementia) study aimed to investigate the feasibility, efficacy, and safety of a combined treatment with choline alphoscerate and nimodipine in patients with SVD and mild-to-moderate cognitive impairment. METHODS: Within this pilot, single-center (university hospital), double-blinded, randomized clinical trial, patients were randomized to two arms: 1-year treatment with nimodipine 30 mg three times a day (TID) plus choline alphoscerate 600 mg twice a day (BID) (arm 1) or nimodipine 30 mg TID plus placebo BID (arm 2). Patients underwent an evaluation at baseline and after 12 months. Cognitive decline, defined as a ≥ 2-point loss on the Montreal Cognitive Assessment, was the primary endpoint. Functional, quality of life, other cognitive measures, and safety were secondary endpoints. Treatment adherence was measured by the count of medicine bottles returned by patients. RESULTS: Sixty-two patients were randomized (31 each arm). Fourteen patients (22%) dropped out for reasons including consent withdrawal (n = 9), adverse reactions (n = 4), and stroke (n = 1). Forty-eight patients (mean ± SD age 75.1 ± 6.8 years), well balanced between arms, completed the study. Regarding adherence, of the prescribed total drug dose, > 75% was taken by 96% of patients for choline alphoscerate, 87.5% for placebo, and 15% for nimodipine. No statistically significant differences were found between the treatment groups for the primary cognitive outcome, nor for the secondary outcomes. Eight patients had non-serious adverse reactions; five presented adverse events. CONCLUSION: Patients' adherence to treatment was low. With this limitation, the combined choline alphoscerate-nimodipine treatment showed no significant effect in our cohort of VCI patients with SVD. The safety profile was good overall. TRIAL REGISTRATION: Clinical Trial NCT03228498. Registered 25 July 2017.

Prognostic role of intrathecal IgM synthesis in multiple sclerosis: Results from a clinical series.

BACKGROUND: There is emerging evidence that intrathecal IgM synthesis (ITMS) is a risk factor for conversion to clinically defined multiple sclerosis (CDMS) in clinically isolated syndrome (CIS) patients. OBJECTIVES: The objective of this study is to verify the prognostic role of ITMS as a risk factor for the second clinical attack in patients after the first demyelinating event. METHODS: Monocentric observational study performed on prospectively acquired clinical data and retrospective evaluation of magnetic resonance imaging (MRI) data. ITMS was assessed according to Reiber's non-linear function. We compared time to the second attack by using Kaplan-Meier curves and performed adjustment by Cox regression analysis. RESULTS: Demographics and clinical data were collected prospectively in a cohort of 68 patients. ITMS occurred in 40% (27/68) of patients who had a higher T1-hypointense lesion load at brain MRI (p = 0.041). In multivariate Cox regression analysis (adjusted for age, sex, baseline Expanded Disability Status Scale, IgG oligoclonal bands and disease-modifying treatment exposure), relapsing-remitting multiple sclerosis (MS) patients with ITMS were at higher risk to experience a second clinical attack (adjusted hazard ratio (aHR) = 6.3, 95% confidence interval (CI) = 2.1-18.4, p = 0.001). CONCLUSION: Together with previous studies, our findings support the role of ITMS as a prognostic biomarker in MS.

Disease-modifying drugs can reduce disability progression in relapsing multiple sclerosis.

An ever-expanding number of disease-modifying drugs for multiple sclerosis have become available in recent years, after demonstrating efficacy in clinical trials. In the real-world setting, however, disease-modifying drugs are prescribed in patient populations that differ from those included in pivotal studies, where extreme age patients are usually excluded or under-represented. In this multicentre, observational, retrospective Italian cohort study, we evaluated treatment exposure in three cohorts of patients with relapsing-remitting multiple sclerosis defined by age at onset: paediatric-onset (≤18 years), adult-onset (18-49 years) and late-onset multiple sclerosis (≥50 years). We included patients with a relapsing-remitting phenotype, ≥5 years follow-up, ≥3 Expanded Disability Status Scale (EDSS) evaluations and a first neurological evaluation within 3 years from the first demyelinating event. Multivariate Cox regression models (adjusted hazard ratio with 95% confidence intervals) were used to assess the risk of reaching a first 12-month confirmed disability worsening and the risk of reaching a sustained EDSS of 4.0. The effect of disease-modifying drugs was assessed as quartiles of time exposure. We found that disease-modifying drugs reduced the risk of 12-month confirmed disability worsening, with a progressive risk reduction in different quartiles of exposure in paediatric-onset and adult-onset patients [adjusted hazard ratios in non-exposed versus exposed >62% of the follow-up time: 8.0 (3.5-17.9) for paediatric-onset and 6.3 (4.9-8.0) for adult-onset, P < 0.0001] showing a trend in late-onset patients [adjusted hazard ratio = 1.9 (0.9-4.1), P = 0.07]. These results were confirmed for a sustained EDSS score of 4.0. We also found that relapses were a risk factor for 12-month confirmed disability worsening in all three cohorts, and female sex exerted a protective role in the late-onset cohort. This study provides evidence that sustained exposure to disease-modifying drugs decreases the risk of disability accumulation, seemingly in a dose-dependent manner. It confirms that the effectiveness of disease-modifying drugs is lower in late-onset patients, although still detectable.

Experience with rituximab therapy in a real-life sample of multiple sclerosis patients.

BACKGROUND: Multiple sclerosis (MS) is an autoimmune, neuroinflammatory, and neurodegenerative disease of the central nervous system. B cells have recently emerged as a promising target to significantly reduce inflammatory disease activity in MS, with successful trial studies using antiCD20 therapies. However, real-life data about safety and efficacy are limited. OBJECTIVES: To analyze the clinical and radiological inflammatory activity, adherence to therapy, and safety of rituximab (RTX) in an MS patients' sample, treated from 2015 to 2018 in our center PATIENTS AND METHODS: Retrospective study on prospectively collected data about relapses, disability progression, and radiological activity (new T2 lesions and Gd-enhancing lesions) were recorded and used to assess no evidence of disease activity (NEDA) at 12 months. RTX-related adverse events were recorded. RTX was administered intravenously at a dosage of 1000 mg twice 2 weeks apart, then every 6 months. RESULTS: Sixty-nine patients were included. Fifty-three (76.8%) had a relapsing-remitting, two a primary progressive course, and 14 a secondary progressive course. The mean follow-up period was 16 ± 9.7 months. Thirty-five (50.7%) patients had relapses in the year prior to RTX therapy, with a mean annualized relapse rate of 0.75, significantly reduced to 0.36 at 12 months (p < 0.001). Among the 36 patients included in the study who had an MRI available at 12 months, MRI activity was reduced from 88% (n = 32) to 8.3% (n = 3) at follow-up (p < 0.001). Twelve (17.4%) patients suspended RTX during the study. CONCLUSIONS: Our real-life experience confirms that off-label therapy with RTX may represent a valid, cost-effective therapeutic option in MS.

Association of nimodipine and choline alphoscerate in the treatment of cognitive impairment in patients with cerebral small vessel disease: study protocol for a randomized placebo-controlled trial-the CONIVaD trial.

BACKGROUND: Vascular cognitive impairment (VCI) is an extremely disabling condition that includes post-stroke dementia and VCI caused by cerebral small vessel disease (SVD). Currently, there is no approved treatment for this condition. Drugs active on the cholinergic pathway have been tested in VCI patients showing positive but limited efficacy. The calcium-antagonist nimodipine also showed some moderate positive effects in VCI patients. AIMS: CONIVaD (choline alphoscerate and nimodipine in vascular dementia) is a pilot, single-center, double-blinded, randomized trial aimed to assess whether the association of choline alphoscerate and nimodipine is more effective than nimodipine alone in reducing cognitive decline in patients with SVD and mild-to-moderate cognitive impairment. METHODS: All patients are evaluated at baseline and after 12 months with: (1) clinical, daily functions, quality of life, and mood assessment and (2) extensive neuropsychological evaluation. After the baseline evaluation, patients are randomly assigned to one of the two arms of treatment: (1) nimodipine 90 mg/die t.i.d plus placebo b.i.d and (2) nimodipine 90 mg t.i.d plus choline alphoscerate 1200 mg/die b.i.d. for a total of 12 months. The primary endpoint is cognitive decline, expressed as the loss of at least two points on the Montreal Cognitive Assessment at 12 months. Secondary endpoints include safety and tolerability, functional, quality of life, and neuropsychological measures. DISCUSSION: CONIVaD study is the first randomized controlled trial to examine the cognitive efficacy of combined choline alphoscerate-nimodipine treatment in VCI patients. Results of this pilot study will serve as a methodological basis for other clinical controlled, multicentric, double-blinded, and randomized trials. TRIAL REGISTRATION: Clinical Trial NCT03228498. Registered 25 July 2017.

Correction: Cognitive impairment in multiple sclerosis: An exploratory analysis of environmental and lifestyle risk factors.

[This corrects the article DOI: 10.1371/journal.pone.0222929.].

Cognitive impairment in multiple sclerosis: An exploratory analysis of environmental and lifestyle risk factors.

BACKGROUND: Many potentially modifiable risk factors for MS are investigated. It is not known, however, if these factors also apply to MS-related cognitive impairment (CI), a frequent consequence of MS. OBJECTIVE: The aim of our study was to assess risk factors for CI in MS patients, focusing on environmental exposures, lifestyle and comorbidities. METHODS: We included MS patients referring to MS Centers in Florence and Barletta between 2014 and 2017. Neuropsychological performance was assessed through the Rao's battery and Stroop test, cognitive reserve (premorbid intelligence quotient-IQ) was evaluated using the National Adult Reading Test (NART). Potential risk factors were investigated through a semi-structured questionnaire. RESULTS: 150 patients were included. CI was detected in 45 (30%) subjects and was associated with older age (p<0.005), older age at MS onset (p = 0.016), higher EDSS score (p<0.005), progressive disease course (p = 0.048) and lower premorbid IQ score (p<0.005). As for risk factors, CI was related with lower physical activity in childhood-adolescence (p<0.005). In women, hormonal therapy resulted to be protective against CI (p = 0.041). However, in the multivariable analysis, the only significant predictors of CI were older age (p<0.05; OR 1.06, 95% CI 1.02-1.10) and lower premorbid IQ (p<0.05; OR 0.93, 95% CI: 0.88-0.98). Removing IQ from the model, CI was associated with higher EDSS (p = 0.030; OR 1.25, 95% CI 1.02-1.53) and, marginally, previous physical activity (p = 0.066; OR 0.49, 95% CI: 0.23-1.05). CONCLUSIONS: Our findings suggest that physical activity in childhood-adolescence could be a contributor to cognitive reserve building, thus representing a potential protective factors for MS-related CI susceptible to preventive strategies.

Hypoxia activates placental growth factor expression in lymphatic endothelial cells.

Placental growth factor (PlGF), a proangiogenic member of vascular endothelial growth family, is active during pathological conditions like cancer, metastasis formation and hind limb ischemia and in wound healing. Endothelial cells express PlGF and hypoxia positively modulates in vitro its expression. To verify whether hypoxia modulates PlGF expression in different cellular contexts and in vivo, we first analyzed five human and five mouse cancer cell lines showing that in eight of them hypoxia positively modulates PlGF. Next, we analyzed xenograft colorectal cancer tumors showing that human cancer cells were able to express PlGF in hypoxic area of the tumor. Surprisingly, we did not visualize mouse PlGF in CD31 positive tumor vessels, but in low CD31 positive vessels, a characteristic of lymphatic vessels. We found that hypoxia effectively activates PlGF expression in lymphatic endothelial cells as well as in LYVE1 positive tumor vessels. We also investigated two additional mouse angiogenic models, hind limb ischemia and wound healing, and we confirmed that lymphatic vessels of both ischemic muscles and skin express PlGF. These results show for the first time that hypoxia activates PlGF expression in lymphatic endothelial cells, which have to be considered an additional source for PlGF production in pathological contexts.

Intravenous immune globulin suppresses angiogenesis in mice and humans.

Human intravenous immune globulin (IVIg), a purified IgG fraction composed of ~ 60% IgG1 and obtained from the pooled plasma of thousands of donors, is clinically used for a wide range of diseases. The biological actions of IVIg are incompletely understood and have been attributed both to the polyclonal antibodies therein and also to their IgG (IgG) Fc regions. Recently, we demonstrated that multiple therapeutic human IgG1 antibodies suppress angiogenesis in a target-independent manner via FcγRI, a high-affinity receptor for IgG1. Here we show that IVIg possesses similar anti-angiogenic activity and inhibited blood vessel growth in five different mouse models of prevalent human diseases, namely, neovascular age-related macular degeneration, corneal neovascularization, colorectal cancer, fibrosarcoma and peripheral arterial ischemic disease. Angioinhibition was mediated by the Fc region of IVIg, required FcγRI and had similar potency in transgenic mice expressing human FcγRs. Finally, IVIg therapy administered to humans for the treatment of inflammatory or autoimmune diseases reduced kidney and muscle blood vessel densities. These data place IVIg, an agent approved by the US Food and Drug Administration, as a novel angioinhibitory drug in doses that are currently administered in the clinical setting. In addition, they raise the possibility of an unintended effect of IVIg on blood vessels.

Human IgG1 antibodies suppress angiogenesis in a target-independent manner.

Aberrant angiogenesis is implicated in diseases affecting nearly 10% of the world's population. The most widely used anti-angiogenic drug is bevacizumab, a humanized IgG1 monoclonal antibody that targets human VEGFA. Although bevacizumab does not recognize mouse Vegfa, it inhibits angiogenesis in mice. Here we show bevacizumab suppressed angiogenesis in three mouse models not via Vegfa blockade but rather Fc-mediated signaling through FcγRI (CD64) and c-Cbl, impairing macrophage migration. Other approved humanized or human IgG1 antibodies without mouse targets (adalimumab, alemtuzumab, ofatumumab, omalizumab, palivizumab and tocilizumab), mouse IgG2a, and overexpression of human IgG1-Fc or mouse IgG2a-Fc, also inhibited angiogenesis in wild-type and FcγR humanized mice. This anti-angiogenic effect was abolished by Fcgr1 ablation or knockdown, Fc cleavage, IgG-Fc inhibition, disruption of Fc-FcγR interaction, or elimination of FcRγ-initated signaling. Furthermore, bevacizumab's Fc region potentiated its anti-angiogenic activity in humanized VEGFA mice. Finally, mice deficient in FcγRI exhibited increased developmental and pathological angiogenesis. These findings reveal an unexpected anti-angiogenic function for FcγRI and a potentially concerning off-target effect of hIgG1 therapies.

Powerful anti-tumor and anti-angiogenic activity of a new anti-vascular endothelial growth factor receptor 1 peptide in colorectal cancer models.

To assess the therapeutic outcome of selective block of VEGFR1, we have evaluated the activity of a new specific antagonist of VEGFR1, named iVR1 (inhibitor of VEGFR1), in syngenic and xenograft colorectal cancer models, in an artificial model of metastatization, and in laser-induced choroid neovascularization. iVR1 inhibited tumor growth and neoangiogenesis in both models of colorectal cancer, with an extent similar to that of bevacizumab, a monoclonal antibody anti-VEGF-A. It potently inhibited VEGFR1 phosphorylation in vivo, determining a strong inhibition of the recruitment of monocyte-macrophages and of mural cells as confirmed, in vitro, by the ability to inhibit macrophages migration. iVR1 was able to synergize with irinotecan determining a shrinkage of tumors that became undetectable after three weeks of combined treatment. Such treatment induced a significant prolongation of survival similar to that observed with bevacizumab and irinotecan combination. iVR1 also fully prevented lung invasion by HCT-116 cells injected in mouse tail vein. Also, iVR1 impressively inhibited choroid neovascularization after a single intravitreal injection. Collectively, data showed the strong potential of iVR1 peptide as a new anti-tumor and anti-metastatic agent and demonstrate the high flexibility of VEGFR1 antagonists as therapeutic anti-angiogenic agents in different pathological contexts.

Epigenetic control of hypoxia inducible factor-1α-dependent expression of placental growth factor in hypoxic conditions.

Hypoxia plays a crucial role in the angiogenic switch, modulating a large set of genes mainly through the activation of hypoxia-inducible factor (HIF) transcriptional complex. Endothelial cells play a central role in new vessels formation and express placental growth factor (PlGF), a member of vascular endothelial growth factor (VEGF) family, mainly involved in pathological angiogenesis. Despite several observations suggest a hypoxia-mediated positive modulation of PlGF, the molecular mechanism governing this regulation has not been fully elucidated. We decided to investigate if epigenetic modifications are involved in hypoxia-induced PlGF expression. We report that PlGF expression was induced in cultured human and mouse endothelial cells exposed to hypoxia (1% O 2), although DNA methylation at the Plgf CpG-island remains unchanged. Remarkably, robust hyperacetylation of histones H3 and H4 was observed in the second intron of Plgf, where hypoxia responsive elements (HREs), never described before, are located. HIF-1α, but not HIF-2α, binds to identified HREs. Noteworthy, only HIF-1α silencing fully inhibited PlGF upregulation. These results formally demonstrate a direct involvement of HIF-1α in the upregulation of PlGF expression in hypoxia through chromatin remodeling of HREs sites. Therefore, PlGF may be considered one of the putative targets of anti-HIF therapeutic applications.

Retinal angiogenesis suppression through small molecule activation of p53.

Neovascular age-related macular degeneration is a leading cause of irreversible vision loss in the Western world. Cytokine-targeted therapies (such as anti-vascular endothelial growth factor) are effective in treating pathologic ocular angiogenesis, but have not led to a durable effect and often require indefinite treatment. Here, we show that Nutlin-3, a small molecule antagonist of the E3 ubiquitin protein ligase MDM2, inhibited angiogenesis in several model systems. We found that a functional p53 pathway was essential for Nutlin-3-mediated retinal antiangiogenesis and disruption of the p53 transcriptional network abolished the antiangiogenic activity of Nutlin-3. Nutlin-3 did not inhibit established, mature blood vessels in the adult mouse retina, suggesting that only proliferating retinal vessels are sensitive to Nutlin-3. Furthermore, Nutlin-3 inhibited angiogenesis in nonretinal models such as the hind limb ischemia model. Our work demonstrates that Nutlin-3 functions through an antiproliferative pathway with conceivable advantages over existing cytokine-targeted antiangiogenesis therapies.

Inhibition of choroidal and corneal pathologic neovascularization by Plgf1-de gene transfer.

PURPOSE: Ocular neovascularization (NV), the primary cause of blindness, typically is treated via inhibition of VEGF-A activity. However, besides VEGF-A, other proteins of the same family, including VEGF-B and placental growth factor (PlGF, all together VEGFs), have a crucial role in the angiogenesis process. PlGF and VEGF, which form heterodimers if co-expressed, both are required for pathologic angiogenesis. We generated a PlGF1 variant, named PlGF1-DE, which is unable to bind and activate VEGFR-1, but retains the ability to form heterodimer. PlGF1-DE acts as dominant negative of VEGF-A and PlGF1wt through heterodimerization mechanism. The purpose of our study was to explore the therapeutic potential of Plgf1-de gene in choroid and cornea NV context. METHODS: In the model of laser-induced choroidal neovascularization (CNV), Plgf1-de gene, and as control Plgf1wt, LacZ, or gfp genes, were delivered using adeno-associated virus (AAV) vector by subretinal injection 14 days before the injury. After 7 days CNV volume was assessed. Corneal NV was induced by scrape or suture procedures. Expression vectors for PlGF1wt or PlGF1-DE, and as control the empty vector pCDNA3, were injected in the mouse cornea after the vascularization insults. NV was evaluated with CD31 and LYVE-1 immunostaining. RESULTS: The expression of Plgf1-de induced significant inhibition of choroidal and corneal NV by reducing VEGF-A homodimer production. Conversely, the delivery of Plgf1wt, despite induced similar reduction of VEGF-A production, did not affect NV. CONCLUSIONS: Plgf1-de gene is a new therapeutic tool for the inhibition of VEGFs driven ocular NV.

A placenta growth factor 2 variant acts as dominant negative of vascular endothelial growth factor A by heterodimerization mechanism.

Angiogenesis is one of the crucial events for cancer development and growth and vascular endothelial growth factor (VEGF) family plays an essential role in this biological phenomenon. The members of VEGF family mainly involved in angiogenesis are VEGF-A, VEGF-B and placental growth factor (PlGF), which exert their activity through the binding and activation of two VEGF receptors, VEGFR-1 and VEGFR-2. Human VEGF-A and PlGF are expressed in different isoforms and have the peculiarity to form heterodimer if co-expressed in the same cell. The difference of two main human PlGF isoforms, PlGF1 and PlGF2, consist in the exclusive ability of PlGF2 to bind heparin and Neuropilin receptors. As previously reported for PlGF1 isoform, we have generated a PlGF2 variant named PlGF2 -DE, in which the residues D(72) and E(73) were substituted with alanine, that is unable to bind and activate VEGFR-1 but is still able to heterodimerize with VEGF. Here we report that overexpression in VEGF-A producing human tumor cell line derived from ovarian carcinoma (A2780) of PlGF2-DE variant by stable transfection, significantly reduces the production of VEGF-A homodimer via heterodimerization, determining a strong inhibition of xenograft tumor growth and associated neoangiogenesis, as well as significant reduction of monocyte-macrophage infiltration. Conversely, the overexpression of PlGF2wt, also reducing the VEGF-A homodimer production comparably to PlGF2-DE variant through the generation of VEGF-A/PlGF2 heterodimer, does not inhibit tumor growth and vessel density compared to control, but induces increase of monocyte-macrophage infiltration. Interestingly the comparison of PlGF2wt with PlGF1wt overexpression evidences a significant reduction of monocyte-macrophages recruitment as unique difference among the activity of the two PlGFwt isoforms. Therefore, the 'less soluble' PlGF2 shows a limited potential in monocyte-macrophages recruitment. In conclusion data here reported demonstrate that PlGF-DE variant acts as 'dominant negative' of VEGF-A independently from the PlGF isoform utilized, that the expression of active PlGF2 homodimer and VEGF-A/PlGF2 heterodimer is sufficient to rescue pro-angiogenic activity lost for reduction of VEGF-A due to heterodimerization mechanism, and that PlGF2 shows lower activity into recruitment of monocyte-macrophage cells compared to PlGF1 isoform.

The biflavonoid amentoflavone inhibits neovascularization preventing the activity of proangiogenic vascular endothelial growth factors.

The proangiogenic members of VEGF family and related receptors play a central role in the modulation of pathological angiogenesis. Recent insights indicate that, due to the strict biochemical and functional relationship between VEGFs and related receptors, the development of a new generation of agents able to target contemporarily more than one member of VEGFs might amplify the antiangiogenic response representing an advantage in term of therapeutic outcome. To identify molecules that are able to prevent the interaction of VEGFs with related receptors, we have screened small molecule collections consisting of >100 plant extracts. Here, we report the isolation and identification from an extract of the Malian plant Chrozophora senegalensis of the biflavonoid amentoflavone as an antiangiogenic bioactive molecule. Amentoflavone can to bind VEGFs preventing the interaction and phosphorylation of VEGF receptor 1 and 2 (VEGFR-1,VEGFR-2) and to inhibit endothelial cell migration and capillary-like tube formation induced by VEGF-A or placental growth factor 1 (PlGF-1) at low µm concentration. In vivo, amentoflavone is able to inhibit VEGF-A-induced chorioallantoic membrane neovascularization as well as tumor growth and associated neovascularization, as assessed in orthotropic melanoma and xenograft colon carcinoma models. In addition structural studies performed on the amentoflavone·PlGF-1 complex have provided evidence that this biflavonoid effectively interacts with the growth factor area crucial for VEGFR-1 receptor recognition. In conclusion, our results demonstrate that amentoflavone represents an interesting new antiangiogenic molecule that is able to prevent the activity of proangiogenic VEGF family members and that the biflavonoid structure is a new chemical scaffold to develop powerful new antiangiogenic molecules.

Patented natural avocado sugars modulate the HBD-2 expression in human keratinocytes through the involvement of protein kinase C and protein tyrosine kinases.

Skin keratinocytes constitute a protective mechanical barrier against invading microorganisms. Stimulated keratinocytes produce endogenous peptides such as the beta-defensins that have direct antimicrobial activity against a broad spectrum of pathogens, including most bacteria, certain fungi and enveloped viruses. In particular, human beta-defensin 2 (HBD-2) is virtually absent in normal skin and its expression in human keratinocytes requires stimulation by cytokines or bacteria. AV119, a patented avocado sugar, triggers the up-regulation of HBD-2, but the signalling mechanisms involved in this up-regulation in stimulated keratinocytes are not fully understood. In the present study, we examined the intracellular signalling pathways and nuclear responses in skin keratinocytes that contribute to HBD-2 gene expression upon stimulation with AV119. Our data provide information on signalling pathways in which the activation of protein tyrosine kinases (PTKs) and protein kinase C (PKC) takes place and leads to AP-1 and HBD-2 gene activation.