Preliminary Results of a Double-Blind Randomized Controlled Trial Evaluating the Cardiometabolic Effects of Levothyroxine and Liothyronine Compared to Levothyroxine with Placebo in Athyreotic Low-Risk Thyroid Cancer Patients

Background: Evidence is needed on the risks and benefits of combination therapy with levothyroxine (LT4)+liothyronine (LT3) for the treatment of hypothyroidism. Objective and Methods: We performed a randomized, double-blind placebo-controlled study to assess the effects of LT4+LT3 therapy versus LT4+placebo in a homogeneous group of athyreotic patients, without cardiovascular risk factors during long-term replacement monotherapy with LT4. The primary objective of the study was to assess the effects of combination LT4+LT3 therapy on heart rate, cardiac rhythm, and sensitive cardiovascular parameters of cardiac morphology and function by means of electrocardiography and Doppler echocardiography. The secondary objective of the study was to evaluate patient compliance, tolerability, and potential adverse events. Results: Thirty-eight patients with postsurgical hypothyroidism satisfying the inclusion criteria were selected from a group of 300 patients with low-risk thyroid cancer followed for a routine follow-up; they were randomized to receive LT4+LT3 or LT4+placebo. Twenty-four patients were evaluated after 1 year of treatment. All clinical and laboratory parameters were compared with the results obtained from 50 healthy euthyroid volunteers without comorbidities, matched for gender, age, physical activity, and lifestyle. Participants and clinicians remained blinded to the treatment allocation. After 1 year of combination therapy, a significant improvement in the diastolic function, evidenced by a significant reduction in the E/e' ratio (p = 0.046) and its positive trend over time, was observed in the LT4+LT3 group versus the LT4+placebo group. In addition, the univariate analyses showed a significant relationship between free triiodothyronine (fT3) levels (in pg/mL) with Δ of variation of the E/e' ratio in the LT4+LT3 group (standardized β coefficient = 0.603 [confidence interval: 0.001-1.248], p = 0.050) after combination therapy. No adverse events including tachycardia, arrhythmias, atrial fibrillation, or other important events occurred between the first administration and the end of the study. Conclusions: In this preliminary report, combination treatment with LT4+LT3 induced favorable changes in cardiovascular parameters of diastolic function without any adverse cardiovascular events. Trial Registration: EUDRACT number: 2017-001261-25.

Right Ventricular Myocardial Involvement in Anderson-Fabry Disease at Diagnosis: Evaluation with Three-Dimensional Strain Imaging

Background: Right ventricular (RV) involvement in Anderson-Fabry disease (AFD) is well known in the advanced stages of the disease RV hypertrophies, but little is known about the early involvement. The aim of our study was to assess RV function in AFD patients at diagnosis. Methods: A total of 23 AFD patients and 15 controls comparable for age and sex were recruited. A complete 2D standard echo with 3D volumetric and strain analysis of RV was performed. Results: Two patient populations, comparable for clinical baseline characteristics were considered. RV free wall thickness was significantly increased in the AFD group. No significant differences in standard RV indices (TAPSE, transverse diameter, tissue Doppler velocities of the lateral tricuspid annulus) were found. A 3D volumetric analysis showed reduced RV ejection fraction and lower values of longitudinal septal, free wall and global longitudinal strain (GLS) in AFD patients. RV free wall thickness significantly correlated with both free wall RV LS and RV GLS. In multiple linear regression analysis, RV free wall thickness was independently associated with RV GLS even after correction for age and heart rate. Conclusions: In AFD patients, 3D echocardiography allows for the identification of early subclinical functional impairment of RV. RV dysfunction is independently associated with RV hypertrophy.

Towards Universally Designed Communication: Opportunities and Challenges in the Use of Automatic Speech Recognition Systems to Support Access, Understanding and Use of Information in Communicative Settings

Unlike physical barriers, communication barriers do not have an easy solution: people speak or sign in different languages and may have wide-ranging proficiency levels in the languages they understand and produce. Universal Design (UD) principles in the domain of language and communication have guided the production of multimodal (audio, visual, written) information. For example, UD guidelines encourage websites to provide information in alternative formats (for example, a video with captions; a sign language version). The same UD for Learning principles apply in the classroom, and instructors are encouraged to prepare content to be presented multimodally, making use of increasingly available technology. In this chapter, I will address some of the opportunities and challenges offered by automatic speech recognition (ASR) systems. These systems have many strengths, and the most evident is the time they employ to convert speech sounds into a written form, faster than the time human transcribers need to perform the same process. These systems also present weaknesses, for example, a higher rate of errors when compared to human-generated transcriptions. It is essential to weigh the strengths and weaknesses of technology when choosing which device(s) to use in a universally designed environment to enhance access to information and communication. It is equally imperative to understand which tools are most appropriate for diverse populations. Therefore, researchers should continue investigating how people process information in a multimodal format, and how technology can be improved based on this knowledge and users' needs and feedback.

587 LEFT ATRIAL APPENDAGE OCCLUSION: A REAL SOLUTION TO CARDIOEMBOLIC RISK OF ATRIAL FIBRILLATION?

82-year-old woman comes to our clinical observation for worsening exertional dyspnea, with ECG evidence of atrial fibrillation (AF) with high ventricular response. Past medical history: previous right breast carcinoma treated in 1998 with quadrantectomy, radiotherapy and hormone therapy. Previous ischemic transitory attack. Hypertension. Dyslipidemia. The patient reports the first episode of paroxysmal AF in 2016, for which anticoagulant therapy with new oral anticoagulants NOACs was started for CHA2DS2VASc=6. During anticoagulant therapy episode of ocular haemorrhage for which the patient discontinued therapy with NOACs and used low-molecular-weight heparin LMWH "as needed" in the course of arrhythmic relapses. In July and August 2019 relapses of symptomatic paroxysmal AF. Multiple attempts to take different anticoagulants (Rivaroxaban, Edoxaban) poorly tolerated. The patient undergoes catheter ablation by isolation of the pulmonary veins (considered first line according to ESC guidelines for the control of symptoms in patients with paroxysmal AF) and percutaneous left atrial appendage occlusion (LAAO), with indication of anticoagulation therapy for at least 4 weeks after the procedure (Apixaban 2.5 mg bid, reduced dose due to the presence of age>80 years and weight<60 kg). At the entrance to our hospital, an ECG is performed with a finding of total arrhythmia from AF with a high ventricular response (HR 130 bpm), conducted with left bundle branch block (LBBB); cardiac echo-Doppler ultrasound is performed with a slight reduction in left ventricular systolic function (EF 45%), second degree diastolic dysfunction with increased filling pressures, moderate mitral valve insufficiency, severe left atrial dilatation (LAVi 125 ml/m2), moderate tricuspid valve insufficiency with moderate pulmonary arterial hypertension (PAPS 55 mmHg), right atrial dilatation, circumferential pericardial detachment, dilated inferior vena cava hyporeactive with breath acts. At blood tests: BNP 1022 pg/ml, sodium 145 mmol/l, potassium 3.5 mmol/l, creatinine 1.17 mg/dl with eGFR 43 ml/min/1.73mq. Rate control therapy with ß-blockers and Digoxin and diuretic therapy with Furosemide and Canrenone is set, with improvement of symptoms and clinical conditions. Anticoagulant therapy with LMWH is also undertaken but the patient shows poor adherence. After home discharge, the patient goes back to the emergency room for dyspnea. Further cardiac echo-Doppler ultrasound is performed with evidence of thrombotic formation in the left atrium of the size of 30×25 mm. Therapeutic dosage LMWH therapy is started with subsequent Warfarin embrication according to INR, obtaining complete resolution of the thrombotic formation.

A systematic review of device-related thrombosis (DRT) after left atrial appendage occlusion (LAAO) proved that the overall incidence of DRT was 3.9% and the median time from procedure to diagnosis of DRT was 1.5 months. According to currently reported cases, most DRTs occur within one year after LAAO. This particular clinical case of DRT three years after LAAO underlines the importance of accurate assessment of the patient's risk profile: LAAO is a valid alternative to anticoagulant therapy in patients at high risk of bleeding but with low embolic risk profile. It's known that high CHA2DS2VASc values ​​and reduced cardiac function are recognized risk factors for thrombus formation, such as patient compliance with antithrombotic therapy. Surely additional studies are needed to determine if the current practice of antithrombotic regimens and duration after LAAO is sufficient.

563 THE ROLE OF ECHOCARDIOGRAPHY FOR MANAGEMENT OF IBRUTINIB RELATED ATRIAL FIBRILLATION: ONE MORE SUPPORT OVER CLINICAL EVALUATION

Background

Ibrutinib is a Bruton tyrosine kinase inhibitor, approved in the last few years for treatment as primary option for all subsets of chronic lymphocytic leukemia (CLL). Its use is associated with increased incidence of atrial fibrillation (AF).

Objectives

Aim of this study is to determine whether there are echocardiographic parameters that could identify patients at major risk of developing ibrutinib-related atrial fibrillation (IRAF).

Methods

We performed a retrospective review of 26 patients (mean age 70,34 ± 11,69; 27% females), admitted at our EchoLab in the last year, who underwent echocardiogram prior to Ibrutinib treatment. Echo-Doppler assessment was realized according to the standards of the European Association of Cardiovascular Imaging (EACVI) standardization of the echo report. Left atrial (LA) strain was measured with EchoPAC, obtaining peak atrial longitudinal strain (PALS) and peak atrial contraction strain (PACS) on 4-chambers and 2-chambers views. Continuous normally distributed variables were compared by using the Student t-test. A probability value < 0,05 was considered statistically significant. Analyses were performed with SPSS version 25 (IBM Corporation, Somers, New York).

Results

Six patients developed IRAF (23%). There weren't differences of clinical characteristics between the two groups (age, body mass index, arterial blood pressure, heart rate and diabetes, hypertension and cardiovascular diseases prevalence). It was noticed that IRAF's group had lower ejection fraction (EF) (54,67 ± 1,96 vs 60,90 ± 4,35, p-value < 0,0001), higher left atrium volume index (48,95 ± 16,31 vs 34,18 ± 9,07, p-value: 0,009), higher pulmonary arterial pressure values (PAPs) (44,16 ± 11,26 vs 32,89 ± 8,44, p-value: 0,015). Furthermore, it was noticed that peak atrial longitudinal strain (PALS) and peak atrial contraction strain (PACS) were reduced in patients who developed IRAF (PALS 4Ch: 18,89 ± 6,90 vs 29,40 ± 9,79, p-value 0,06; PACS 4Ch: 10,56 ± 5,66 vs 14,31 ± 5,72, p-value: 0,25; PALS 2Ch: 23,36 ± 5,02 vs 32,88 ± 16,57, p-value: 0,28; PACS 2Ch: 13,61 ± 8,16 vs 18,33 ± 9,87, p-value: 0,39), but not statistically significant, probably due to the sample size.

Conclusions

This is a preliminary pilot study which confirms the data already present in the literature. The importance of baseline evaluation by echocardiogram including measurement of atrial strain of patients before starting treatment with Ibrutinib is emphasized since, given the same anthropometric characteristics and risk factors, there are echocardiographic parameters that help us to identify patients at major risk of developing IRAF. Pharmacological intervention tailored on this type of basal echocardiographic evaluation could allow the reduction of IRAF's onset and improve patient outcomes in the long term. Certainly, further follow-up studies will be needed to confirm this hypothesis.

Towards a More Inclusive Learning Environment: The Importance of Providing Captions That Are Suited to Learners' Language Proficiency in the UDL Classroom

Captions have been found to benefit diverse learners, supporting comprehension, memory for content, vocabulary acquisition, and literacy. Captions may, thus, be one feature of universally designed learning (UDL) environments [1, 4]. The primary aim of this study was to examine whether captions are always useful, or whether their utility depends on individual differences, specifically proficiency in the language of the audio. To study this, we presented non-native speakers of English with an audio-visual recording of an unscripted seminar-style lesson in English retrieved from a University website. We assessed English language proficiency with an objective test. To test comprehension, we administered a ten-item comprehension test on the content of the lecture. Our secondary aim was to compare the effects of different types of captions on viewer comprehension. We, therefore, created three viewing conditions: video with no captions (NC), video with premade captions (downloaded from the university website) (UC) and video with automatically generated captions (AC). Our results showed an overall strong effect of proficiency on lecture comprehension, as expected. Interestingly, we also found that whether captions helped or not depended on proficiency and caption type. The captions provided by the University website benefited our learners only if their English language proficiency was high enough. When their proficiency was lower, however, the captions provided by the university were detrimental and performance was worse than having no captions. For the lower proficiency levels, automatic captions (AC) provided the best advantage. We attribute this finding to pre-existing characteristics of the captions provided by the university website. Taken together, these findings caution institutions with a commitment to UDL against thinking that one type of caption suits all. The study highlights the need for testing captioning systems with diverse learners, under different conditions, to better understand what factors are beneficial for whom and when.

Clinical features associated with ADB-BUTINACA exposure in patients attending emergency departments in England

OBJECTIVE

Synthetic cannabinoid receptor agonists (SCRA) are commonly encountered new psychoactive substances. Here we report the recent detection of ADB-BUTINACA in samples from patients attending United Kingdom emergency departments with toxicity after suspected drug misuse and describe the associated clinical features.

METHODS

Consenting adults (≥16 y) presenting to participating hospitals with toxicity after suspected drug misuse have been included in the Identification Of Novel psychoActive substances (IONA) study since March 2015. Demographic and clinical features are recorded and blood and/or urine samples analysed using high-resolution accurate mass liquid chromatography-mass spectrometry.

RESULTS

By December 2021, analytical data were available for 1279 IONA participants and ADB-BUTINACA was detected in at least one sample from 10 (9 males, age range 16-51 median 45 years), all presenting since February 2021. Smoking 'spice' was reported by four patients, two had ingested edible "cannabis" gums and four reported heroin use (2 intravenous, 1 smoked, 1 route not known). Co-use of pregabalin (oral) and crack cocaine (smoked) were also reported. In 3 cases ADB-BUTINACA was the only substance detected, while in seven other substances of misuse were also detected including other SCRA, opioids, benzodiazepines cocaine and pregabalin. Clinical features reported in these 2 groups respectively included reduced level of consciousness (3/3, 6/7), agitation (0/3, 4/7), tachycardia (0/3, 3/7), seizures (1/3, 1/7), hallucinations (1/3, 1/7), hypotension (1/3, 1/7). Metabolic acidosis (1/3, 0/7) and respiratory acidosis (1/3, 0/7), All 10 patients recovered with supportive care, including intubation and ventilation for one case. The median length of hospital stay was 19 h (range 2.6-131 h).

CONCLUSIONS

ADB-BUTINACA has recently emerged as a drug of misuse in England. Clinical features of toxicity are consistent with those of other SCRA and include reduced level of consciousness, respiratory and/or metabolic acidosis, seizures, confusion and hallucinations.

Wasted myocardial work may affect left ventricular remodelling occurrence after primary percutaneous coronary revascularization

Funding Acknowledgements

Type of funding sources: None.

Introduction

Left ventricular function recovery (LV-REC) or left ventricular adverse remodelling (LV-REM) after acute myocardial infarction (AMI) play an important role for identifying patients at risk of heart failure.

Purpose

In this study we aim to evaluate the usefulness of non-invasive myocardial work (MW), a new index of global and regional myocardial performance, to predict LV-REC or LV-REM after AMI.

Methods

Fifty patients with AMI (mean age, 63,8 ±13,4 years), treated by primary percutaneous coronary intervention (PCI), were prospectively enrolled.  They underwent a baseline transthoracic Doppler echocardiography (TTE) within 48 hours after PCI and a second TTE after a median of 31 days during the follow-up. MW was derived from the strain-pressure loops, integrating in its calculation the non-invasive arterial pressure, according to standard speckle tracking echocardiography recommendations. LV-REC was defined as an absolute improvement of left ventricular ejection fraction (LVEF) ≥ 5% from LVEF at baseline, whereas LV-REM was defined as an increase of ≥ 20% of the LV end diastolic volume (LVEDV) at 1 month follow up.

Results

We overall found a significant improvement from baseline to one-month follow-up for values of LVEF (49,8 ± 9,5 % vs 52,8 ± 9,3 %, p = 0.001), Global Longitudinal Strain (GLS) (-13,4 ± 3,9 % vs -18,7 ± 5,4 %, p = 0.016), Global Work Index (GWI) (1368,6 ±435,2 vs 1788 ±493 mmHg/%, p = 0.0001), Global Work Efficiency (GWE) (89,96 ± 9,3 % vs 91,3 ± 6,4 %,  p = 0.001), Global Constructive Work (GCW) (1619,16 ± 497,9 mmHg/% vs 2008,6 ± 535,3 mmHg/%, p = 0.0001), Global Wasted Work (GWW) (188,8 ± 19,8 mmHg/% vs 149,2 ± 16,5 mmHg/%). However, LV-REC at 1 month of follow-up was observed only in 36 % of the population enrolled, whereas LV-REM was described in 18% of cases. Using ROC curve analysis, we identified a cut off value of 202 mmHg/% for baseline GWW (Sensitivity 75%, Specificity 62%, AUC 0.6667, CI 95%: 0,51618 - 0,81715, p =0.0001) to identify patients with LV-REM at 1 month. With regards to conventional echo parameters, patients with LV-REC showed lower baseline Wall Motion Score Index (WMSI) than those without LV-REC (1,73 vs 1,38, p = 0.007).

Conclusions

Among standard and advanced TTE parameters, only baseline GWW is able to predict early LV-REM at 1 month after primary PCI. Therefore, it could be used during baseline evaluation of AMI patients for a more accurate stratification of those at higher risk of heart failure. However, further larger scale studies are needed to validate these findings. Abstract table 1  Abstract table 2

709 Non-invasive assessment of myocardial work: an useful tool for predicting LV remodelling after myocardial infarction?

Aims

Left ventricular function recovery (LV-REC) or left ventricular adverse remodelling (LV-REM) after acute myocardial infarction (AMI) play an important role for identifying patients at risk of heart failure. In this study we aim to evaluate the usefulness of non-invasive myocardial work (MW), a new index of global and regional myocardial performance, to predict LV-REC or LV-REM after AMI.

Methods and results

Fifty patients with AMI (mean age, 63.8 ± 13.4 years), treated by primary percutaneous coronary intervention (PCI), were prospectively enrolled. They underwent a baseline transthoracic Doppler echocardiography (TTE) within 48 h after PCI and a second TTE after a median of 31 days during the follow-up. MW was derived from the strain-pressure loops, integrating in its calculation the non-invasive arterial pressure, according to standard speckle tracking echocardiography recommendations. LV-REC was defined as an absolute improvement of left ventricular ejection fraction (LVEF) ≥ 5% from LVEF at baseline, whereas LV-REM was defined as an increase of ≥ 20% of the LV end diastolic volume (LVEDV) at 1 month follow-up. We overall found a significant improvement from baseline to one-month follow-up for values of LVEF (49.8 ± 9.5% vs. 52.8 ± 9.3%, P = 0.001), global longitudinal strain (GLS) (−13.4 ± 3.9% vs. −18.7 ± 5.4%, P = 0.016), global work index (GWI) (1368.6 ± 435.2 vs. 1788 ± 493 mmHg/%, P = 0.0001), global work efficiency (GWE) (89.96 ± 9.3% vs. 91.3 ± 6.4%, P = 0.001), global constructive work (GCW) (1619.16 ± 497.9 mmHg/% vs. 2008.6 ± 535.3 mmHg/%, P = 0.0001), global wasted work (GWW) (188.8 ± 19.8 mmHg/% vs. 149.2 ± 16.5 mmHg/%). However, LV-REC at 1 month of follow-up was observed only in 36% of the population enrolled, whereas LV-REM was described in 18% of cases. Using ROC curve analysis, we identified a cut off value of 202 mmHg/% for baseline GWW (sensitivity 75%, specificity 62%, AUC 0.6667, CI 95%: 0.51618–0.81715, P = 0.0001) to identify patients with LV-REM at 1 month. With regards to conventional echo parameters, patients with LV-REC showed lower baseline wall motion score index (WMSI) than those without LV-REC (1.73 vs. 1.38, P = 0.007).

Conclusions

Among standard and advanced TTE parameters, only baseline GWW is able to predict early LV-REM at 1 month after primary PCI. Therefore, it could be used during baseline evaluation of AMI patients for a more accurate stratification of those at higher risk of heart failure. However, further larger scale studies are needed to validate these findings.

Methylglyoxal affects cognitive behaviour and modulates RAGE and Presenilin-1 expression in hippocampus of aged mice

Methylglyoxal (MG), a potent glycotoxin that can be found in the diet, is one of the main precursors of Advanced glycation end products (AGEs). It is well known that modifications in lifestyle such as nutritional interventions can be of great value for preventing brain deterioration. This study aimed to evaluate in vivo how an oral MG treatment, that mimics a high MG dietary intake, could affect brain health. From our results, we demonstrated that MG administration affected working memory, and induced neuroinflammation and oxidative stress by modulating the Receptor for Advanced glycation end products (RAGE). The gene and protein expressions of RAGE were increased in the hippocampus of MG mice, an area where the activity of glyoxalase 1, one of the main enzymes involved in MG detoxification, was found reduced. Furthermore, at hippocampus level, MG mice showed increased expression of proinflammatory cytokines and increased activities of NADPH oxidase and catalase. MG administration also increased the gene and protein expressions of Presenilin-1, a subunit of the gamma-secretase protein complex linked to Alzheimer's disease. These findings suggest that high MG oral intake induces alteration directly in the brain and might establish an environment predisposing to AD-like pathological conditions.

Prediction of early left ventricular recovery and adverse remodelling in patients with acute myocardial infarction: the role of non-invasive myocardial work evaluation

Background

Left ventricular recovery (LVR) and adverse left ventricular remodelling (aLVR) after acute myocardial infarction (AMI) play an important prognostic role.

Purpose

Our aim was to evaluate the usefulness of non-invasive myocardial work (MW), a new index of global and regional myocardial performance, to predict LVR and aLVR.

Methods

Fifty patients with AMI (mean age, 63,8±13,4 years), treated by percutaneous coronary intervention (PCI), were prospectively enrolled and underwent a transthoracic Doppler echocardiography within 48 hours after PCI and a median of 31 days at follow-up. Myocardial work is derived from the strain-pressure relation, integrating in its calculation the non-invasive arterial pressure. Segmental LVR was defined as an absolute improvement of left ventricular ejection fraction (LVEF) ≥5% from LVEF at the baseline. The aLVR was defined as an increase of ≥20% of the LV end diastolic volume (LVEDV) at 1 month follow up.

Results

We found significant differences between the baseline and the follow-up value of LVEF (49,28 vs 52,80 p=0.001), Global Longitudinal Strain (GLS) (−13,41 vs −18,72, p=0.016), Global Work Index (GWI) (1368,68 vs 1788,08, p<0.0001), Global Work Efficiency (GWE) (86,96 vs 91,36, p=0.001), and Global Constructive Work (GCW) (1619,16 vs 2008,68, p<0.0001). The LVR at 1 month of follow-up was observed in 36% of the population enrolled, whereas aLVR was described in 18% of cases. Using ROC curve analysis, we identified a cut off value of 137 mmHg/% for baseline Global Wasted Work (Sensitivity 100%, Specificity 57,14%, AUC 0.6667, CI 95%: 0,51618- 0,81715, p<0.0001) to identify patients with aLVR at 1 month. With regards to conventional echo parameters, patients with LVR showed lower baseline Wall Motion Score Index (WMSI) than those with LVR (1,73 vs 1,38, p=0.007).

Conclusions

Baseline global wasted work can predict early adverse left ventricular remodelling at 1 months after AMI. These parameters could be used at baseline in order to predict worse outcome in AMI patients. Further larger scale studies are needed to validate these findings.

Funding Acknowledgement

Type of funding sources: None.

HLM, a TNM-like classification for heart failure, compared with other nosologies at 12 months follow-up

Background

Heart failure (HF) is the pandemic of the third millennium with the highest mortality among general population, while lung cancer is the second most common cause of death. As cancer, HF can affect close organs, as lungs, or can reach peripheral organs (kidney, liver, brain), leading to multi-organ dysfunction, like cancer metastasis.

Purpose

We proposed a new staging system named HLM, analogous to TNM classification used in oncology, which refers to heart damage (H), lung involvement (L), and malfunction (M) of peripheral organs. The aim of this study is a comparison between HLM and NYHA, ACC/AHA and MAGGIC scores to assess the most accurate prognosis of HF patients in terms of rehospitalization for acute HF (AHF) or major adverse cardiac and cerebrovascular events (MACCE), and cardiac death.

Methods

We performed a single-center observational study of HF patients. All parameters for heart, lungs and peripheral organs function were examined. Each patient was classified according to HLM, NYHA, ACC/AHA and MAGGIC score at the entrance and at the discharge. Rehospitalization for MACCE or AHF and cardiac death were checked at 12 months follow up.

Results

We enrolled 2054 patients: 68.5% males, 31.3% females, mean age 70.18±7.48 years. Among them, overall survival curves regarding rehospitalization for MACCE, AHF and cardiac death at 12 months, show that HLM classification is as valid as the others (p<0.001). In particular, the area under the ROC curve (AUC) is greater for HLM than NYHA, ACC/AHA and MAGGIC score in terms rehospitalisation for MACCE (HLM=0.687; NYHA=0.642; ACC/AHA=0.604; MAGGIC=0.657) or AHF (HLM=0.662; NYHA=0.652; ACC/AHA=0.604; MAGGIC=0.662) and cardiac death (HLM=0.783; NYHA=0.712; ACC/AHA=0.623; MAGGIC=0.737).

Conclusion(s)

According to our results, HLM classification has greater prognostic power compared to other nosologies in terms of rehospitalization for MACCE, AHF and cardiac death for HF patients, thanks to a more accurate evaluation of the systemic impact of heart failure. Such a multivariable, holistic approach should be used in HF patients, rather than a “cardiocentric” approach, in order to address the pathophysiological mechanisms underlining heart abnormalities, improving clinical management and costs.

Funding Acknowledgement

Type of funding source: None

A new methodological approach for in vitro determination of the role of DNA methylation on transcription factor binding using AlphaScreen® analysis: Focus on CREB1 binding at hBDNF promoter IV

BACKGROUND

DNA methylation plays a relevant role in the regulation of gene transcription, but currently the exact quantification of transcription factors binding to methylated DNA is not being determined. The binding of the transcription factor cAMP response element-binding protein-1 to its cognate CpG containing motif is known to be impaired upon methylation. It thus represents a paradigmatic system to experimentally verify the validity of a new in vitro method to measure the role of methylation on DNA/transcription factors binding.

METHOD

An AlphaScreen® assay was developed to quantitatively measure the contribution of DNA CpG methylation on the interaction with transcription factors. The method was validated measuring the variation in affinity of cAMP response element-binding protein-1 and its recognition motif in human Brain-derived neurotrophic factor gene exon IV promoter as a function of CpG methylation.

RESULTS

For the first time, a quantitative direct correlation between DNA methylation and transcription factors binding is reported showing a dramatic reduction in binding affinity between fully methylated and non-methylated DNA.

COMPARISON WITH EXISTING METHODS

This methodology allows to directly measure DNA/transcription factors binding ability as a function of DNA methylation levels thus improving not quantitative methods available today. Moreover, it allows to work with purified proteins and oligonucleotides without need of chromatin.

CONCLUSIONS

The present methodology is suggested as a new analytical tool for the quantitative determination of the effect of CpG methylation on the interaction of gene promoters with transcription factors regulating gene expression, a key epigenetic mechanism implicated in many physiological and pathological conditions.

P322 Dynamic changes of left ventricular cardiac mechanics in takotsubo syndrome: a preliminary study

Background

Takotsubo syndrome (TTS) is a transient left ventricular (LV) heart failure due to a reversible systolic dysfunction, usually recovering within days or weeks.

Purpose

To assess the dynamic changes of LV cardiac mechanics in a small cohort of TTS patients through the estimation of myocardial work, a newly developed non-invasive approach which allows correction of global longitudinal strain (GLS) for systolic blood pressure.

Methods

Twenty-four patients (mean age, 63.8 ± 8.4 yy; all female) with TTS diagnosis were retrospectively enrolled. Data from transthoracic two-dimensional and speckle-tracking echocardiography on admission and at 3 months follow-up were collected. Global myocardial work index (GWI, mmHg%) was calculated as the area of the LV pressure (LVP)-strain loop, where LVP was estimated noninvasively using a standard waveform fitted to valvular events and scaled to systolic blood pressure. From GWI we also assessed: global constructive work (GCW, mmHg%: work performed during shortening in systole + negative work during lenghtening in isovolumetric relaxation, IVR), global wasted work (GWW, mmHg%: negative workperformed by a segment during lengthening in systole + work performed during shortening in IVR) and global work efficiency (GWE, %: constructive work divided by the sum of constructive and wasted work). Baseline demographic and clinical features, including in-hospital adverse events as acute heart failure, cardiogenic shock and cardiac death, were also assessed.

Results

On overall population, a reduced ejection fraction (EF) and GLS were detected at hospital admission, with a substantial improvement at discharge and at follow-up (from 41.7 ± 8.3% to 54.5 ± 6.5% to 60.2 ± 4.6% for EF and from -11.7 ± 4.5% to -16.2 ± 4.2 to -21.3 ± 2.8% for GLS, respectively). Similarly, global MWI and MWE both showed a positive trend during the hospital course and at follow-up: MWI increased from 1048.8 ± 580.5 to 1522.4 ± 695.4 to 2021.1 ± 388.6 mmHg% and MWE from 78.7 ± 10.2 to 91.1 ± 4.6 to 94.5 ± 3.8 %. Increasing in MWE has been obtained through an improvement of GCW (from 1195.9 ± 537.2 to 1651.3 ± 700.3 to 2316.8 ± 490.6 mmHg%) and a contemporary decreasing in GWW (from 237.9 ± 137.2 to 106 ± 37.2 to 131.8 ± 150.8 mmHg%).

In-hospital adverse events occurred in 8 (50%) patients. Of note, despite EF and GLS at admission showed no significant differences, patients experiencing in-hospital adverse events showed lower value of acute MWI (725.6 ± 289.6 vs 1371.9 ± 632.1 mmHg%; p= 0.02) and MWE (73.6 ± 3.4 vs 83.8 ± 12.4%; p= 0.04) compared to patients without in-hospital complications.

Conclusion

Non-invasive assessment of myocardial work through echocardiographic strain-based technique could be useful to demonstrate the peculiar dynamic changes of cardiac mechanics and for a better risk stratification in TTS patients.

Abstract P322 Figure.

P874Role of Genetic Polymorphisms of ion channels in the pathophysiology of coronary microvascular dysfunction and ischemic heart disease: an update

Background

Ischemic heart disease (IHD) is classically associated with coronary artery disease (CAD) and conventional cardiovascular risk factors. However, IHD may exhibit in the absence of CAD, because of different pathophysiological mechanisms, such as the presence of specific genetic variants of ion channels, which act mainly in the microcirculation. Recently, we reported the correlation between some single nucleotide polymorphisms (SNPs) of ion channels genes and the presence of IHD, independently from the presence of conventional cardiovascular risk factors. The goal of this study is to confirm the results of the previous study on a bigger population and discover new SNPs of ion channels genes which may be associated with IHD.

Methods

A prospective, observational, single-center study was conducted on patients candidates for coronary angiography. Patients were divided in three groups: G1, coronary artery disease; G2, microvascular disfunction; G3, normal. Genetic polymorphisms relative to KCNJ11 encoding for the Kir6.1 and Kir6.2 subunits of K-ATP channels and KCNE1 encoding for the MinK subunit of IKs channels were analyzed.

Results

603 consecutive patients (G1: 409; G2:76; G3:118) were enrolled. Genetic analysis for the three groups showed a statistically significant difference for the SNP S38G of KCNE1 (p=0.001) and for the variants rs5215, rs5218, rs5219 of KCNJ11 (p<0.0001), as well as comparing G1-G3 (S38G p=0.006; rs5215, rs5218 and rs5219 p<0.0001). Regarding G1-G2 we confirmed differences only for the variants rs5215 (p<0.0001), rs5218 (p=0.005) and rs5219 (p=0.024), while regarding G2-G3 we found differences for the variants S38G, rs5215 e rs5219 (p<0.0001). A multivariate analysis was performed and highlighted that the SNP rs5215_GG of KCNJ11 may represent an IHD independent protective factor (p<0.0001; OR: 0.036; 95.0% CI: 0.018–0.069).

Conclusion

These results confirm the importance of genetic susceptibility and the role of SNPs of ion channels genes in the determinism of IHD, independently from the conventional cardiovascular risk factors. Moreover, these results may represent a future perspective for a genic therapy for IHD.

Epigenetic modifications of Dexras 1 along the nNOS pathway in an animal model of multiple sclerosis

The development of multiple sclerosis, a major neurodegenerative disease, is due to both genetic and environmental factors that might trigger aberrant epigenetic changes of the genome. In this study, we analysed global DNA methylation in the brain of mice upon induction of experimental autoimmune encephalomyelitis (EAE), and the effect of environmental enrichment (EE). We demonstrate that global DNA methylation decreased in the striatum, but not in the cortex, of EAE mice compared to healthy controls, in particular in neuronal nitric oxide synthase (nNOS)-positive interneurons of this brain area. Also, in the striatum but again not in the cortex, decreased DNA methylation of the nNOS downstream effector, dexamethasone-induced Ras protein 1 (Dexras 1), was observed in EAE mice, and was paralleled by an increase in its mRNA. Interestingly, EE was able to revert EAE effects on mRNA expression and DNA methylation levels of Dexras 1 and reduced gene expression of nNOS and 5-lipoxygenase (Alox5). Conversely, interleukin-1β (IL-1β) gene expression was found up-regulated in EAE mice compared to controls and was not affected by EE. Taken together, these data demonstrate an unprecedented epigenetic modulation of nNOS-signaling in the pathogenesis of multiple sclerosis, and show that EE can specifically revert EAE effects on Dexras 1 along this pathway.

Growth factors, their receptor expression and markers for proliferation of endothelial and neoplastic cells in human osteosarcoma

Osteosarcoma is the most common primary malignant tumour of the bone. Although new therapies continue to be reported, osteosarcoma-related morbidity and mortality remain high. Modern medicine has greatly increased knowledge of the physiopathology of this neoplasm. Novel targets for drug development may be identified through an understanding of the normal molecular processes that are deeply modified in pathological conditions. The aim of the present study is to investigate, by immunohistochemistry, the localisation of different growth factors and of the proliferative marker Ki-67 in order to determine whether these factors are involved in the transformation of osteogenic cells and in the development of human osteosarcoma. We observed a general positivity for NGF - TrKA - NT3 - TrKC - VEGF in the cytoplasm of neoplastic cells and a strong expression for NT4 in the nuclear compartment. TGF-beta was strongly expressed in the extracellular matrix and vascular endothelium. BDNF and TrKB showed a strong immunolabeling in the extracellular matrix. Ki-67/MIB-1 was moderately expressed in the nucleus of neoplastic cells. We believe that these growth factors may be considered potential therapeutic targets in the treatment of osteosarcoma, although proof of this hypothesis requires further investigation.

Endothelial cells and normal breast epithelial cells enhance invasion of breast carcinoma cells by CXCR-4-dependent up-regulation of urokinase-type plasminogen activator receptor (uPAR, CD87) expression

Here we show the increase of invasion of three breast cancer cell lines (8701-BC, MDA-MB-231 and SKBR3) upon long-term co-incubation with culture medium of normal microvascular endothelial cells (MVEC) and normal breast epithelial cells (HB2). The enhancement of invasion relied on the interaction of microvascular endothelial cell and normal breast epithelial cell CXCL12 (SDF1) chemokine, whose expression by breast cancer cells was very low, with the cognate CXCR4 receptor of malignant cells, which resulted in over-expression of the urokinase-type plasminogen activator receptor (uPAR) on their surfaces. uPAR over-expression, showed by RT-PCR and Western blotting, was paralleled by increased urokinase-type plasminogen activator (uPA) partitioning on the cell surface with respect to the fluid phase, as demonstrated by zymography. Long-term interaction of SDF1 with CXCR4 stimulated sustained activation of JNK phosphorylation. Blocking antibodies to CXCR4 were able to block the endothelial/epithelial cell-dependent enhancement of invasion, as well as to inhibit SDF1-CXCR4-dependent JNK phosphorylation and uPAR over-expression of malignant cells. We suggest that acquisition of the angiogenic phenotype by breast cancer cells triggers an amplification loop, in which endothelial cells and normal breast epithelial cells of the tumour cooperate to provide facilitated routes to cell invasion and metastasis and to enhance the aggressive phenotype of cancer cells.

Remediation of waters contaminated with ionic herbicides by sorption on polymerin

This study investigated the sorption of paraquat and 2,4-D on polymerin, the humic acid-like fraction of olive mill wastewater. Effects of pH, contact time, initial concentration and sorbent dosage on the sorption of both herbicides were studied. The sorption mechanism of paraquat on polymerin was consistent with the ion exchange of this herbicide with Ca, Mg and K natively occurring in the sorbent; in contrast, 2,4-D was bound to polymerin by hydrogen bonding. Simulated wastewaters contaminated with paraquat were purified after three sorption cycles on polymerin renewed at each cycle, at a solid/liquid ratio of 0.5, whereas those containing 2,4-D showed a maximal residue removal of 44% after two sorption cycles at the same ratio. The possible application of this model to other water-soluble herbicides, as well as the possible exploitation of polymerin as a bio-filter for the decontamination of pollution point sources is briefly discussed.

Systemic sclerosis fibroblasts inhibit in vitro angiogenesis by MMP-12-dependent cleavage of the endothelial cell urokinase receptor

Failure of endothelial cells to develop new vessels in response to hypoxia is a distinctive feature of systemic sclerosis (SSc) in the avascular phase. We have previously shown that SSc endothelial cells over-express matrix metalloproteinase-12 (MMP-12), which blocks angiogenesis by cleavage of the endothelial urokinase-type plasminogen activator receptor (uPAR). In the present study, we have investigated whether over-expression of MMP-12 and of angiostatic factors, or hypo-expression of angiogenic factors by SSc fibroblasts, contributes to impaired angiogenesis in SSc. Dermal fibroblasts were isolated from healthy subjects (N-Fb) and patients with diffuse SSc (SSc-Fb). Angiogenesis of target normal human microvascular endothelial cells (H-MVECs) was assayed by Matrigel invasion, cell proliferation, and capillary morphogenesis. uPAR cleavage and MMP-12 activity were evaluated by western blotting. We show that the over-expression of MMP-12 by SSc-Fb determines uPAR cleavage in H-MVECs. Conditioned medium from SSc-Fb impaired H-MVEC proliferation, invasion, and capillary morphogenesis. Anti-MMP-12 antibodies restored such impairment. Altered expression of angiostatic/angiogenic factors, including transforming growth factor beta1, did not account for SSc-Fb-dependent impairment of angiogenesis. The over-expression of MMP-12 by both SSc-Fb and SSc endothelial cells indicates that MMP-12 over-production may have a critical pathogenic role in SSc-associated vascular alterations.

Effects of blocking urokinase receptor signaling by antisense oligonucleotides in a mouse model of experimental prostate cancer bone metastases

An important factor implicated in tumor cell predisposition for invasion and metastasis is the malignancy-related upregulation of urokinase plasminogen activator receptor (uPAR). uPAR signals by activating different tyrosine kinases in different cells. We examined the effects of inhibiting uPAR signaling by inhibition of uPAR expression with antisense oligonucleotides (aODNs) in PC3 human prostate cancer cells and evaluated aODN effect in a mouse model of prostate cancer bone metastasis. Following uPAR aODN treatment, PC3 cells exhibited a strong decrease in uPAR expression, evaluated by flow cytometry and by polymerase chain reaction, and of FAK/JNK/Jun phosphorylation. The synthesis of cyclins A, B, D1 and D3 was inhibited, as shown by Western blotting, flow cytometry and polymerase chain reaction, and PC3 cells accumulated in the G2 phase of the cell cycle. PC3 cells' adhesion was unaffected, while proliferation and invasion of Matrigel were impaired. A total of 60 mice were subjected to intracardiac injection of PC3 cells and were randomly assigned to three groups: aODN (treated with 0.5 mg intraperitoneum/mouse/day), dODN (treated with the same amounts of a degenerated ODN) and control (injected with a saline solution). At 28 days after heart injection, mice were subjected to a digital scan of total body radiography, which revealed 80% reduction in mice affected by bone metastasis. The use of uPAR aODNs produced a substantial prophylactic effect against prostate cancer bone metastasis, which has to be ascribed to downregulation of uPAR expression.

Regulation of urokinase/urokinase receptor interaction by heparin-like glycosaminoglycans

We show here that the interaction between the urokinase-type plasminogen activator and its receptor, which plays a critical role in cell invasion, is regulated by heparan sulfate present on the cell surface and in the extracellular matrix. Heparan sulfate oligomers showing a composition close to the dimeric repeats of heparin (glucosamine-NSO(3)(6-OSO(3))-iduronic acid(2-OSO(3))) n = 5 and n > 5, where iduronic acid may alternate with glucuronic acid, exhibit affinity for urokinase plasminogen activator and confer specificity on urokinase/urokinase receptor interaction. Cell surface clearance of heparan sulfate reduces the affinity of such interaction with a parallel decrease of specific urokinase binding in the presence of an unaltered expression of receptor. Transfection of human urokinase plasminogen activator receptor in normal Chinese hamster ovary fibroblasts and in Chinese hamster ovary cells defective for the synthesis of sulfated glycosaminoglycans results in specific urokinase/receptor interaction only in nondefective cells. Heparan sulfate/urokinase and receptor/urokinase interactions exhibit similar K(d) values. We concluded that heparan sulfate functions as an adaptor molecule that confers specificity on urokinase/receptor binding.

Cell invasion is affected by differential expression of the urokinase plasminogen activator/urokinase plasminogen activator receptor system in muscle satellite cells from normal and dystrophic patients

The aim of this study was to evaluate the differential expression and the function in cell movement and proliferation of the urokinase plasminogen activator (u-PA) system in muscle satellite cells (MSC) of normal individuals and patients with Duchenne muscular dystrophy (DMD). By immunoenzymatic, zymographic, and radioligand binding methods and by quantitative polymerase chain reaction of the specific mRNA we have shown that both normal and DMD MSC produce u-PA and the plasminogen activator inhibitor-1 and express u-PA receptors (u-PAR). During the proliferation phase of their growth-differentiation program, MSC from DMD patients show more u-PAR than their normal counterpart, produce more plasminogen activator inhibitor-1, and release low amounts of u-PA into the culture medium. By Boyden chamber Matrigel invasion assays we have shown that normal MSC are more prone than DMD cells to spontaneous invasion but, when subjected to a chemotactic gradient of u-PA, DMD MSC sense the ligand much better and to a greater extent than normal MSC. u-PA also stimulates proliferation of MSC, but no difference is observable between normal and DMD patients. Antagonization of u-PA/u-PAR interaction with specific anti-u-PA and anti-u-PAR monoclonal antibodies and with antisense oligonucleotides inhibiting u-PAR expression indicates that u-PA/u-PAR interaction is required in spontaneous and u-PA-induced invasion, as well as in u-PA-induced proliferation.

Transforming growth factor beta-1 stimulates invasivity of hepatic stellate cells by engagement of the cell-associated fibrinolytic system

The activation of hepatic stellate cells (HSC) during liver fibrogenesis has been shown to be mediated by paracrine and autocrine loops involving transforming growth factor-beta1 (TGF-beta1) as the main fibrogenic mediator secreted by activated macrophages, endothelial cells and liberated by disintegrated platelets. The cell-associated plasminogen activation system regulates extracellular matrix (ECM) catabolism and cell movement. We have studied whether TGF-beta1 could modulate the plasminogen activation system in human HSC and the role of such protease system in the activity of TGF-beta1 on HSC. Urokinase plasminogen activator receptors (u-PAR), u-PA and plasminogen activator inhibitor type 1 (PAI-1) were determined by immunoassay and RNase protection assay. Cell migration, evaluated either as chemotaxis or as chemoinvasion, was studied in Boyden chambers after addition of TGF-beta1, and inhibition with anti-u-PA and anti-u-PAR antagonists [antibodies against u-PA and u-PAR and antisense oligonucleotides (aODN) against u-PAR mRNA]. We have shown that TGF-beta1 is not mitogenic for HSC, while it is a powerful motogen either in chemotaxis or chemoinvasion assays. TGF-beta1 up-regulates the synthesis and expression of PAI-1, as well as u-PAR expression and exposure at the cell membrane, while it does not affect u-PA levels. TGF-beta1-dependent chemoinvasion of reconstituted basement membrane exploits the cell-associated plasminogen activation system, since it is blocked by monoclonal antibodies against u-PA and against various u-PAR domains, as well as by anti-u-PAR aODN. We have also observed a cumulative effect of TGF-beta1, b-FGF and PDGF in the invasion assay of HSC: in the presence of low amounts of TGF-beta1 the chemoinvasive activity of PDGF and bFGF is dramatically increased. Also this cooperation requires u-PAR and is inhibited by monoclonal antibodies against u-PAR domains I, II and III.

100th American society for microbiology annual meeting

The 100th ASM Annual Meeting, attended by approximately 10,000 delegates, continued the trend of concentrating on bacteria and antibacterial therapy, mixed with genomics and a diverse number of additional topics. Of the various marketable drug classes, the quinolones received attention with respect to susceptibility studies and several drug comparison studies. New marketable drugs were also of interest, especially given the reservoirs of resistance presented by several speakers. Drugs in development include the antibacterial daptomycin and protegrins and the antifungal lipodepsinonapeptides and echinocandins, to name a few. It is still unclear whether or not antibiotic treatment regimens for Chlamydia pneumonia will he necessary, as association of this bacteria with several chronic diseases, such as atherosclerosis and asthma, was discussed. The development of novel antibiotics was highlighted and the potential role that microbial genomics technology could play was a recurring theme. In fact, a number of symposia treated the increasingly popular topic of genomics in a variety of themes, including phenotyping arrays, transcriptional profiling, proteomics, expression profiling, genome sequencing, target areas or essentiality of genes via gene knockout systems, the role of genomics in pharmaceutical development and fungal genomics. Similarly, genomics plays a role in developing a deeper appreciation for classical areas of interest in microbial physiology, such as gene regulation, cell division, fatty acid biosynthesis, DNA replication and cell signalling. Even in the bio-inorganic field of study in microbial metabolite activation, genomics plays a role. The sequencing of the large gene clusters of the auxiliary proteins necessary to synthesise or activate the metallo-proteins provided insights into the mechanisms of activation of these microbial enzymes, including the genes for the nif gene cluster in Azotobacter vinelandii, the urease from Kiebsiella aerogenes and the three hydrogenases in Ralstonia eutropha.

Functions of the fibrinolytic system in human Ito cells and its control by basic fibroblast and platelet-derived growth factor

During liver fibrogenesis, hepatic stellate cells (HSC) proliferate and migrate under the influence of growth factors, including platelet-derived growth factor (PDGF) and basic-fibroblast growth factor (b-FGF). The plasminogen activation system regulates extracellular matrix (ECM) catabolism and cell movement. We evaluated the expression and biological functions of the plasminogen activation system in human HSC and its interaction with PDGF and b-FGF. Urokinase-plasminogen activator receptors (u-PAR) were measured by radioligand binding, cell cross-linking, immunoassay, and RNAse protection assay. u-PA and plasminogen activator inhibitors (PAIs) expression and activities were analyzed by zymography, immunoassay, and RNase protection assay. Cell migration and proliferation, studied in Boyden chambers and by microscopic counting, were evaluated after the addition of PDGF, b-FGF, and blockade with anti-u-PA, anti-u-PAR antibodies, and antisense oligodeoxynucleotides (aODN) against u-PAR mRNA. We have shown that HSC produce u-PAR, u-PA, and PAI-1. PDGF and b-FGF up-regulate u-PA and u-PAR, but not PAI-1, and exogenous addition of u-PA stimulates HSC proliferation, chemotaxis, and chemoinvasion. Inhibition of u-PA/u-PAR with antibodies against u-PA or u-PAR and with u-PAR aODN inhibit the proliferative, chemotactic, and chemoinvasive activity of PDGF and b-FGF. These findings indicate that u-PA and u-PAR are required for the mitogenic and chemoinvasive activity of PDGF and b-FGF on HSC.

Urokinase-dependent angiogenesis in vitro and diacylglycerol production are blocked by antisense oligonucleotides against the urokinase receptor

The plasminogen activator system is known to play a crucial role in the angiogenesis process by modulating the adhesive properties of endothelial cells to the extracellular matrix and cell-cell interaction. In the present study, we demonstrated that the urokinase-type plasminogen activator (u-PA) induced neovascular growth in the avascular rabbit cornea and dose-dependently promoted growth, chemotaxis, and matrix invasion of cultured endothelial cells. Interaction between u-PA and its receptor appears to be mandatory for the angiogenic effect of u-PA because monoclonal antibodies anti-u-PA and anti-u-PA receptor (u-PAR) blocked the proangiogenic effects of u-PA at the endothelial cell level. We then assessed the signaling pathway activated in endothelial cells by u-PA. u-PAR activation by u-PA produced de novo synthesis of diacylglycerol (DAG) from glucose by a cytochalasin B-inhibitable mechanism, indicating the involvement of a specific glucose transporter (GLUT). Endothelial cells expressed GLUT2, whose activation was tyrosine kinase-dependent and protein kinase C (PKC)-independent. The increase of glucose uptake led to DAG production, which resulted in PKC activation/translocation. Impairment of u-PAR availability by monoclonal antibodies and by antisense oligonucleotides (aODN) against u-PAR mRNA inhibited glucose uptake, DAG neosynthesis, and PKC activation, resulting in the blockade of endothelial cell proliferation, chemotaxis, and chemoinvasion. These data suggest that u-PAR activation consequent to the binding of u-PA can be regarded as an "angiogenic switch" and disclose the possibility that an anti-u-PAR aODN strategy may efficiently target endothelial cell function to control angiogenesis in vivo.

Antisense targeting of the urokinase receptor blocks urokinase-dependent proliferation, chemoinvasion, and chemotaxis of human synovial cells and chondrocytes in vitro

Proliferation and invasion of synovial pannus in rheumatoid arthritis and cartilage remodeling in osteoarthritis are key events in development of disability of arthritic joints. The mechanisms that trigger these events are still poorly understood. The production of urokinase-type plasminogen activator (u-PA) by synovial cells and chondrocytes and the subsequent interaction of u-PA with its membrane receptor (u-PAR) is under the control of a variety of growth factors and cytokines released within the inflamed joints. Here we show that u-PA, on interaction with the specific receptor, regulates movement and invasion as well as proliferation of human synovial cells and chondrocytes. Targeting the urokinase receptor with an antisense oligonucleotide blocks the u-PA-dependent synoviocyte and chondrocyte proliferation and chemoinvasion, suggesting a possible use for this new class of drugs in the progression of the disease in rheumatoid arthritis and osteoarthritis.

Mechanism of prostaglandin E2 transport across the plasma membrane of HeLa cells and Xenopus oocytes expressing the prostaglandin transporter "PGT"

We recently identified a novel prostaglandin transporter called PGT (Kanai, N., Lu, R., Satriano, J. A., Bao, Y., Wolkoff, A. W., and Schuster, V. L. (1995) Science 268, 866-869). Based on initial functional studies, we have hypothesized that PGT might mediate the release of newly synthesized prostaglandins (PG), epithelial transport of PGs, or metabolic clearance of PGs. Here we examined the mechanism of PGT transport as expressed in HeLa cells and Xenopus oocytes, using isotopic PG influx and efflux studies. In both native HeLa cells and oocytes, cell membranes were poorly permeable to PGs. In contrast, in oocytes injected with PGT mRNA, the PG influx permeability coefficient was 90-157 times that of oocytes injected with water. The rank order substrate profile was PGF2alpha approximately PGE2 > TXB2 >> 6 keto-PGF1alpha. PG influx displayed an overshoot with rapid accumulation of tracer PGE2, followed by a gradual return to baseline. Based on estimated oocyte volumes, the PGT-mediated accumulation of PGE2 reached steady state at intra-oocyte concentrations 25-fold higher than the external media. The accumulation of PG was not due to intracellular binding or metabolism. PGT-mediated uptake was ATP- and temperature-dependent, but not sodium-dependent, and was inhibited by disulfonic stilbenes, niflumic acid, and the thiol reactive anion MTSES (Na(2-sulfonatoethyl)methanethiosulfonate). [3H]PGE2 efflux from PGT-transfected HeLa cells was stimulated by external (trans) PGE2 in a dose-dependent fashion and was inhibited by bromcresol green and 4,4'-diisothiocyanatostilbene-2,2'-disulfonate. Membrane depolarization inhibited uptake of [3H]PGE2, consistent with a model of net outward movement of negative charge during the translocation event. These findings suggest that PGT mediates [3H]PGE2 accumulation via obligatory, electrogenic anion exchange.

Peripheral hypertension and alterations in pulmonary vascular regulation

We have recently reported in normal isolated-perfused rat lungs that low basal tone appears to be regulated by nitric oxide (NO)-dependent and -independent mechanisms of soluble guanylate cyclase activation. In this study, we examined the role of NO in the regulation of pulmonary artery (PA) tone from rats with renin-dependent hypertension. Rats were made hypertensive by ligating the abdominal aorta above the left and below the right renal artery (aortic coarctation, AC). Mean arterial pressure significantly increased from 119 +/- 8.4 mmHg in control animals to 156 +/- 15 mmHg 7-14 days after AC surgery. PA pressures, however, remained unchanged (8.5 +/- 3.4 mmHg in control animals vs. 11 +/- 3.3 mmHg in AC animals). Hypoxic contractions in U-46619 precontracted isolated small PA (160-260 microns diameter) were significantly increased from 51 +/- 13 mg in the control group to 142 +/- 38 mg (P < or = 0.05) in AC animals. Nitro-L-arginine (NLA; 100 microM) contractions were also enhanced in the AC animal. The enhanced NLA response may correlate with an increase in endothelial cell NO synthase (NOS) as detected by Western blotting (132 +/- 28% of control; P < 0.05). These data suggest that, in this renin-dependent model of systemic hypertension, there is increased endothelial cell NOS activity that maintains low PA tone, preventing the lung from developing increased pressures.

Interaction of urokinase-type plasminogen activator with its receptor rapidly induces activation of glucose transporters

The interaction of urokinase-type plasminogen activator (u-PA) or of u-PA amino-terminal fragment (u-PA-ATF) with the cell surface receptor (u-PAR) was found to stimulate an increase of glucose uptake in many cell lines, ranging from normal and transformed human fibroblasts, mouse fibroblasts transfected with human u-PAR, and cells of epidermal origin. Such increase of glucose uptake reached a peak within 5-10 min, depending on the cell line, and occurred through the facilitative glucose transporters (GLUTs), since it was inhibited by cytochalasin B. Each cell line showed a specific mosaic of glucose transporter isoforms, GLUT2 being the most widespread and GLUT1 the most abundant, when present. u-PAR stimulation was followed by translocation of GLUT1 from the microsomal to the membrane compartment, as shown by both immunoblotting and immunofluorescence of sonicated plasma membrane sheets and by activation of GLUT2 on the cell surface. Both translocation and activation resulted inhibitable by protein-tyrosine kinase inhibitors and independent of downregulation of protein kinase C (PKC). The increase of intracellular glucose was followed by neosynthesis of diacylglycerol (DAG) from glucose, as previously shown. Such neosynthesis was completely inhibited by impairment of facilitative GLUT transport by cytochalasin B. DAG neosynthesis was followed by activation of PKC, whose activity translocated into the intracellular compartment (PKM), where it probably phosphorylates substrates required for u-PAR-dependent chemotaxis. Our data show that u-PAR-mediated signal transduction, related with u-PA-induced chemotaxis, involves activation of tyrosine kinase-dependent glucose transporters, leading to increased de novo DAG synthesis from glucose, eventually resulting in activation of PKC.

Determinants of renal vasoconstriction after systemic inhibition of nitric oxide synthesis in rats

The effects of NG-nitro-L-arginine (L-NNA, 10 mg/kg i.v.) on renal hemodynamics were examined in control rats, rats in which renal perfusion pressure was prevented from rising after L-NNA by constricting the abdominal aorta, and rats in which tubuloglomerular feedback was inhibited by furosemide pretreatment, ureteral ligation, or both interventions combined. In control rats, L-NNA increased (P < 0.05) renal vascular resistance (274 +/- 27%) along with systemic arterial (54 +/- 4%) and renal perfusion (54 +/- 5%) pressures and decreased (P < 0.05) renal blood flow (57 +/- 4%). In rats in which renal perfusion pressure was prevented from increasing along with systemic arterial pressure (54 +/- 4%), the L-NNA-induced elevation of renal vascular resistance (173 +/- 27%) was less intense (P < 0.05). In another study, where renal perfusion pressure was fixed at pre-L-NNA levels, L-NNA-induced increases in renal vascular resistance (130 +/- 20%) were attenuated (P < 0.05) further with furosemide pretreatment (52 +/- 12%), with ureteral ligation (75 +/- 10%), and with furosemide pretreatment and ureteral ligation combined (32 +/- 8%). These data suggest that vasoconstrictor mechanisms linked to tubuloglomerular feedback and perfusion pressure elevation contribute to renal vasoconstriction after systemic inhibition of nitric oxide synthesis with L-NNA.

Activity of carbapenem BMS-181139 against Pseudomonas aeruginosa is not dependent on porin protein D2

The broad antipseudomonal spectrum of the carbapenem BMS-181139 includes clinical strains and laboratory mutants of Pseudomonas aeruginosa that are resistant to imipenem. Unlike other known carbapenems (meropenem, panipenem, biapenem, and BO-2727), which have reduced activity against imipenem-resistant strains of P. aeruginosa, BMS-181139 was equally active against imipenem-susceptible (D2-sufficient) and imipenem-resistant (D2-deficient) strains. Conversely, imipenem and meropenem activities were the same against the susceptible parental strains and their BMS-181139-resistant mutants. Whereas basic amino acids antagonized the antipseudomonal activities of imipenem and meropenem, they had no effect on the activity of BMS-181139. These results suggest that the uptake of BMS-181139 into pseudomonal cells occurs by a non-D2 pathway. Compared with imipenem and meropenem, BMS-181139 may have a slightly higher affinity for penicillin-binding protein 2 (PBP-2) of P. aeruginosa. The rates of resistance development to imipenem, meropenem, and BMS-181139 in P. aeruginosa strains were similar; resistance occurred at frequencies of approximately 10(-7) to 10(-8). Resistance to BMS-181139 in P. aeruginosa is presumed to be caused by its diminished permeability since no change in their penicillin-binding protein affinities or beta-lactamase levels could be detected. In summary, BMS-181139 is a new carbapenem which differs from other known carbapenems in its lack of cross-resistance with imipenem. This difference could be explained by the permeation of BMS-181139 through a non-D2 channel, compared to the preferential uptake of other carbapenems by the D2 porin.

Plasminogen activator and receptor in osteoarthritis

Evidence indicates that breakdown of articular cartilage resulting in the loss of normal joint function is the distinctive feature of osteoarthritis. Degradation of cartilage extracellular matrix components involves the action of at least 2 classes of proteinases: serine proteinases and metalloproteinases. Receptors have been described on a wide range of cell lines for many such proteinases [urokinase-type plasminogen activator (u-PA), plasminogen/plasmin, collagenase], which subsequently activate each other on the solid phase of the cell surface, leading to cartilage destruction. We review the leading role of u-PA and its receptor (u-PAR) in cartilage degradation.

Reversion of the invasive phenotype of transformed human fibroblasts by anti-messenger oligonucleotide inhibition of urokinase receptor gene expression

The receptors for urokinase plasminogen activator were studied in both normal human fibroblasts (WI-38 cells) and their SV40-transformed counterpart (VA-13 cells). We have shown that transformed cells expose 10 times more urokinase plasminogen activator receptors (u-PAR) than normal cells. By cross-linking aliquots of cell lysates with the aminoterminal fragment of the A chain of u-PA, containing the receptor-binding sequence, we have observed a u-PAR concentration at focal contacts in both cell lines. Only transformed cells were able to efficiently invade the basement membrane Matrigel. Switching off the receptor gene expression by the anti-messenger oligodeoxynucleotides strategy abolished the invasive properties of transformed cells. The anti-messenger oligodeoxynucleotide sequence we have designed inhibited the u-PAR gene expression, lowering both the receptor and the receptor mRNA. This indicates that overexpression of u-PAR gene is itself responsible for invasivity of transformed fibroblasts in our cell model system and that antisense compound therapy may prove to be of clinical interest in the control of cancer spreading.

Control of the chondrocyte fibrinolytic balance by the drug piroxicam: relevance to the osteoarthritic process

OBJECTIVE

Since the plasminogen activator [PA/plasminogen activator inhibitor (PAI) system is believed to be involved in a breakdown of articular cartilage in osteoarthritis (OA), we studied the modulation of single components of the fibrinolytic system (urokinase-type plasminogen activator, u-PA; plasminogen activator inhibitor-1, PAI-1; the surface receptor for u-PA, u-PAR) in human chondrocytes in the presence of piroxicam.

METHODS

The drug was added to the chondrocyte culture medium either directly or by supplementing chondrocyte cultures with synovial fluid (SF) from patients with OA treated with piroxicam. We have shown u-PAR M(r) 55000 Da on human chondrocytes in suspension culture by cross linking chondrocyte lysates with 125I-labelled amino-terminal fragment (ATF) of human u-PA, which frames the sequence that specifically interacts with u-PAR.

RESULTS

Such receptors decrease upon incubation of chondrocytes with piroxicam or with SF from patients treated with piroxicam. The culture medium of treated chondrocytes showed decreased fibrinolytic activity when compared with untreated controls, while PAI activity was increased in both SF chondrocyte culture medium following piroxicam treatment. At the same time, internalization of u-PA/u-PAR complexes increased after incubation of chondrocytes with piroxicam or PAI-1 rich SF.

CONCLUSION

Our results indicate that the drug induces the surface clearance u-PAR by internalization of u-PA/PAI-/u-PAR complexes. Thus piroxicam reduces both the soluble fibrinolytic activity of human chondrocytes (increase of PAI activity and decrease of released u-PA) and the cell associated u-PA activity (clearance of u-PAR by internalization). The drug dependent changes in the fibrinolytic system suggest that piroxicam may be useful in preventing or limiting perilacunar cartilage damage in OA.

Production of second messengers following chemotactic and mitogenic urokinase-receptor interaction in human fibroblasts and mouse fibroblasts transfected with human urokinase receptor

We studied urokinase-type plasminogen activator (u-PA)-dependent chemotaxis and DNA synthesis in both human fibroblasts and LB6 mouse fibroblasts transfected with human u-PA receptor (u-PAR) gene (LB6 clone 19). Both cell lines have receptors for the amino-terminal fragment of u-PA (u-PA-ATF). We observed that u-PA and u-PA-ATF stimulated chemotactic migration of both LB6 clone 19 cells and human fibroblasts, which could be impaired by down-regulation of protein kinase C (PKC) with phorbol myristate acetate (PMA). While LB6 clone 19 cells were unable to undergo mitosis following exposure to either u-PA or u-PA-ATF, human fibroblasts were stimulated to mitosis by exogenous addition of native u-PA, and u-PA-ATF was ineffective. The mitogenic activity of u-PA on human fibroblasts could also be impaired by down-regulation of PKC with PMA. We studied second messenger formation following u-PAR stimulation. Neither inositol lipid metabolism nor intracellular Ca2+ content were affected, while an increase of diacylglycerol (DAG) generation was observed. Such DAG formation was related to de novo synthesis from glucose and was dependent on ligand-receptor interaction. Both u-PA-ATF and the native u-PA molecule were able to stimulate DAG formation, u-PA being from three to fourfold more efficient than ATF. These data suggest that u-PAR stimulation per se is sufficient to trigger DAG formation. The native molecule confers on the cell an additional stimulus, possibly related with the activation of a u-PA-catalytic site-dependent substrate. Such stimulation allows the cell to reach the DAG threshold level required to trigger DNA synthesis.