The work to swing limbs in humans versus chimpanzees and its relation to the metabolic cost of walking

Compared to their closest ape relatives, humans walk bipedally with lower metabolic cost (C) and less mechanical work to move their body center of mass (external mechanical work, WEXT). However, differences in WEXT are not large enough to explain the observed lower C: humans may also do less work to move limbs relative to their body center of mass (internal kinetic mechanical work, WINT,k). From published data, we estimated differences in WINT,k, total mechanical work (WTOT), and efficiency between humans and chimpanzees walking bipedally. Estimated WINT,k is ~ 60% lower in humans due to changes in limb mass distribution, lower stride frequency and duty factor. When summing WINT,k to WEXT, between-species differences in efficiency are smaller than those in C; variations in WTOT correlate with between-species, but not within-species, differences in C. These results partially support the hypothesis that the low cost of human walking is due to the concerted low WINT,k and WEXT.

Metabolic cost and mechanical work of walking in a virtual reality emulator

PURPOSE

The purpose of this study was to investigate the metabolic cost (C), mechanical work, and kinematics of walking on a multidirectional treadmill designed for locomotion in virtual reality.

METHODS

Ten participants (5 females, body mass 67.2 ± 8.1 kg, height 1.71 ± 0.07 m, age 23.6 ± 1.9 years, mean ± SD) walked on a Virtuix Omni multidirectional treadmill at four imposed stride frequencies: 0.70, 0.85, 1.00, and 1.15 Hz. A portable metabolic system measured oxygen uptake, enabling calculation of C and the metabolic equivalent of task (MET). Gait kinematics and external, internal, and total mechanical work (WTOT) were calculated by an optoelectronic system. Efficiency was calculated either as WTOT/C or by summing WTOT to the work against sliding frictions. Results were compared with normal walking, running, and skipping.

RESULTS

C was higher for walking on the multidirectional treadmill than for normal walking, running, and skipping, and decreased with speed (best-fit equation: C = 20.2-27.5·speed + 15.8·speed2); the average MET was 4.6 ± 1.4. Mechanical work was higher at lower speeds, but similar to that of normal walking at higher speeds, with lower pendular energy recovery and efficiency; differences in efficiency were explained by the additional work against sliding frictions. At paired speeds, participants showed a more forward-leaned trunk and higher ankle dorsiflexion, stride frequency, and duty factor than normal walking.

CONCLUSION

Walking on a multidirectional treadmill requires a higher metabolic cost and different mechanical work and kinematics than normal walking. This raises questions on its use for gait rehabilitation but highlights its potential for high-intensity exercise and physical activity promotion.

The impact of PARP inhibitors in the whole scenario of ovarian cancer management: A systematic review and network meta-analysis

BACKGROUND

Carboplatin is still the cornerstone of the first-line treatment in advanced Epithelial Ovarian Cancer (aEOC) management and the clinical response to platinum-derived agents remains the major predictor of long-term outcomes.

PATIENT AND METHODS

We aimed to identify the best treatment of the aEOC in terms of efficacy and safety, considering all treatment phases. A systematic literature search has been done to compare all treatments in aEOC population. Randomized trials with available survival and safety data published in the 2011-2022 timeframe were enclosed. Only trials reporting the BRCA or HRD (Homologous Recombination Deficiency) status were considered.

DATA EXTRACTION AND SYNTHESIS

A ranking of treatment schedules on the progression-free survival (PFS) endpoint was performed. The random-effect model was used to elaborate and extract data. The Network Meta-Analysis (NMA) by Bayesian model was performed by STATA v17. Data on PFS were extracted in terms of Hazard ratio with relative confidence intervals.

RESULTS

This NMA involved 18 trials for a total of 9105 patients. Within 12 treatment groups, we performed 3 different sensitivity analyses including "all comers" Intention to Treat (ITT) population, BRCA-mutated (BRCAm), and HRD subgroups, respectively. Considering the SUCRA-reported cumulative PFS probabilities, we showed that in the ITT population, the inferred best treatment was niraparib plus bevacizumab with a SUCRA of 96.7. In the BRCAm subgroup, the best SUCRA was for olaparib plus chemotherapy (96,9). The HRD population showed an inferred best treatment for niraparib plus bevacizumab (SUCRA 98,4). Moreover, we reported a cumulative summary of PARPi toxicity, in which different 3-4 grade toxicity profiles were observed, despite the PARPi "class effect" in terms of efficacy.

CONCLUSIONS

Considering all aEOC subgroups, the best therapeutical option was identified as PARPi plus chemotherapy and/or antiangiogenetic agents, suggesting the relevance of combinatory approaches based on molecular profile. This work underlines the potential value of "chemo-free" regimens to prolong the platinum-free interval (PFI).

Arthroscopic capsular release for frozen shoulder: when etiology matters

PURPOSE

No therapeutic intervention is universally accepted for frozen shoulder, and the most effective management to restore motion and diminish pain has yet to be defined. The aim of this study was to investigate functional and psychological outcomes in patients who underwent arthroscopic capsular release for a frozen shoulder.

METHODS

A retrospective study with prospective data collection was conducted with 78 patients suffering from frozen shoulder resistance to conservative treatment. Considering the etiology, there were 36 (46.2%) idiopathic, 31 (39.7%) postoperative, and 11 (14.1%) posttraumatic cases. Preoperatively, each patient was evaluated with the range of motion (ROM) assessment and the Constant-Murley score (CMS). At follow-up, the 4-point subjective satisfaction scale (SSS), the ROM assessment, the SF-12 questionnaire, the numerical rating scale (NRS) for the subjective assessment of pain, the CMS and the Hospital Anxiety and Depression Scale (HADS) were assessed.

RESULTS

After a mean follow-up of 54.2 ± 22.3 months, ROM and CMS showed a statistically significant improvement between pre- and postoperative values (all p < 0.001). Before surgery, the mean CMS was 36.9% that of sex- and age-matched healthy individuals, and all patients showed a CMS lower than the normative data. At the final follow-up visit, the mean CMS was 99.9% that of sex- and age-matched healthy individuals, and 49 (62.8%) patients showed a CMS equal to or higher than the normative data. The mean increase in the CMS was 56.1 ± 8.3 points. The mean SSS, HADS-A, HADS-D, and NRS were 3.7 ± 0.5, 2.5 ± 1.6, 2.2 ± 1.3, and 2.2 ± 1.0, respectively. All patients returned to their previous level of work and sports activity after 2 and 2.5 months, respectively. The multivariate analysis showed the association between a higher postoperative CMS and the idiopathic etiology of a frozen shoulder (p = 0.004, β = 3.971). No intraoperative complications occurred. Postoperatively, four patients (5.1%) were treated with intra-articular steroid injections to manage residual symptoms. One patient (1.3%) with a postoperative frozen shoulder showed persistent symptoms and underwent a new successful arthroscopic capsular release.

CONCLUSION

High patient satisfaction and statistically significant ROM and CMS recovery can be achieved after arthroscopic capsular release to manage frozen shoulder. Better functional outcomes are expected when the etiology is idiopathic. Results can help surgeons identify the patients who will most benefit from surgery and should be discussed with the patient.

LEVEL OF EVIDENCE

III.

First-line systemic treatment for hepatocellular carcinoma: A systematic review and network meta-analysis

The rapid development of novel therapeutic options for advanced hepatocellular carcinoma (aHCC) has generated some uncertainty about the rational choice of the systemic upfront treatment. So far, a variety of therapeutic strategies have been investigated, including the combination of immunecheckpoint inhibitors and anti-VEGF. To identify the treatment that should be preferred as front-line approach, we compared the efficacy and toxicity of a variety of therapeutic strategies. With this aim, we performed a systematic review and a meta-analysis of randomized clinical trials. OS, PFS, ORR and tolerability outcomes were considered, and for each outcome the treatment ranking was evaluated by the surface under the cumulative rankings (SUCRAs). Combination of Camrelizumab + Rivoceranib scored the best in OS, followed by Sintilimab + Bevacizumab, whereas Lenvatinib + Pembrolizumab showed higher probability to be the best treatment in PFS and Sintilimab + Bevacizumab performed best in ORR. Finally, Durvalumab is the most tolerated treatment.

Complementary use of statistical parametric mapping and gait profile score to describe walking alterations in multiple sclerosis: a cross-sectional study

Gait analysis is often used to study locomotor alterations in people with multiple sclerosis (PwMS), but the large number of extracted variables challenges the interpretability. In this paper, we analysed gait alterations by combining the Gait Profile Score (GPS), which summarizes kinematic locomotor deviations, and Statistical Parametric Mapping (SPM), which compares kinematics and kinetics over the whole gait cycle. Eleven PwMS and 11 speed-matched Healthy Controls (HC) underwent overground gait analysis. GPS were compared through independent-samples t-tests; sagittal-plane kinematics and power at hip, knee, and ankle were compared through SPM Hotelling's-T2 and SPM t-tests. Spearman's correlation coefficients (r) between GPS and clinical outcomes were also calculated. PwMS had higher GPS than HC (PwMS = 8.74 ± 2.13°; HC = 5.01 ± 1.41°;p < 0.001). Multivariate SPM found statistically significant differences at 0-49%, 70-80%, and 93-99% of stride (p < 0.05) and univariate analysis showed reduced ankle dorsiflexion, and lower knee flexion during pre-swing and swing. GPS correlated with Expanded Disability Status Scale (r = 0.65; 95%C.I.[0.04,0.91]; p = 0.04) and 2-Minute Walking Test (r = -0.65; 95%C.I.[-0.91,-0.04]; p = 0.04). GPS in conjunction with SPM revealed multi-joint kinematic alterations on sagittal plane involving distal joint angles, ankle and knee, during the stance phase with no changes at the proximal level. Gait deviations were more pronounced in PwMS with higher disability and walking limitations.

COVID-19 Containment Measures-a Step Back for Walking Mobility? A 2-Year, 60-Country Analysis of the Apple Mobility Data

BACKGROUND

COVID-19 containment measures curb viral spread but may hamper walking mobility. As a low daily step count is associated with increased noncommunicable diseases and mortality, assessing the relationship between pandemic responses and walking mobility can help trade-off public health measures. We investigated the association between containment stringency and walking mobility across 60 countries in the period between January 21, 2020 and January 21, 2022 and modeled how this could impact mortality hazard.

METHODS

Walking mobility was measured through the Apple Mobility Trends, containment measures stringency index through the Oxford COVID-19 response tracker (which considers local policies on closures, healthcare, and economy), and meteorological data by National Oceanic and Atmospheric Administration weather stations. Walking mobility was regressed over stringency in a mixed-effect model with weather variables as covariates. The impact of stringency on all-cause mortality due to reduced mobility was modeled based on regression results, prepandemic walking mobility, and the association between step count and all-cause mortality hazard.

RESULTS

Across the 60 countries, the average stringency was 55 (9) (mean [SD]) out of 100. Stringency was negatively associated with walking mobility; a log-linear model fitted data better than a linear one, with a regression coefficient for stringency on ln (walking mobility) (95% confidence interval) of  -1.201 × 10-2 (-1.221 × 10-2 to -1.183 × 10-2). Increasing stringency, thus decreasing walking mobility, nonlinearly incremented the modeled all-cause mortality hazard by up to ∼40%.

CONCLUSIONS

In this study, walking mobility was negatively associated with containment measures stringency; the relationship between stringency, mobility, and the subsequent impact on health outcomes may be nonlinear. These findings can help in balancing pandemic containment policies.

From the Lab to Real Life: Monitoring Cardiorespiratory Fitness during the COVID-19 Pandemic through Wearable Devices. An Exploratory Longitudinal Study on Healthy Participants

COVID-19 containment measures hampered population cardiorespiratory fitness (which can be quantified as peak oxygen consumption (V.O_2peak)) and the possibility to assess it using laboratory-based techniques. Although it is useful to ascertain the V.O_2peak recovery after lockdowns, the community and most scientific institutions were unable to evaluate it. Wearable devices may provide the opportunity to estimate cardiorespiratory fitness outside of the laboratory, without breaking self-isolation; herein, we explore the feasibility of this approach. Fifteen healthy participants were tested every 2 weeks for 10 weeks during a reduction of containment measures after a strict lockdown. Physical activity levels were measured using the International Physical Activity Questionnaire-Short Form (IPAQ-SF). V.O_2peak was estimated through a previously validated test based on the speed of a 60 m sprint run, the baseline-to-peak heart rate (HR) variation, and the velocity of HR decay after the sprint, and measured through a wearable HR monitor. Participants increased physical activity from the end of lockdown (1833 [917–2594] MET-min/week; median [1st quartile–3rd quartile]) until the end of follow-up (2730 [1325–3380] MET-min/week). The estimated V.O_2peak increased by 0.24 ± 0.19 mL/(min*kg*week) (regression coefficient ± standard error). Based on previous knowledge on the impact of inactivity on V.O_2peak, our study indicates that a 10-week period of reducing the stringency of containment measures may not be sufficient to counteract the detrimental effects of the preceding lockdown.

miR-221/222 as biomarkers and targets for therapeutic intervention on cancer and other diseases: A systematic review

Among deregulated microRNAs (miRs) in human malignancies, miR-221 has been widely investigated for its oncogenic role and as a promising biomarker. Moreover, recent evidence suggests miR-221 as a fine-tuner of chronic liver injury and inflammation-related events. Available information also supports the potential of miR-221 silencing as promising therapeutic intervention. In this systematic review, we selected papers from the principal databases (PubMed, MedLine, Medscape, ASCO, ESMO) between January 2012 and December 2020, using the keywords “miR-221” and the specific keywords related to the most important hematologic and solid malignancies, and some non-malignant diseases, to define and characterize deregulated miR-221 as a valuable therapeutic target in the modern vision of molecular medicine. We found a major role of miR-221 in this view.

Spns2 Transporter Contributes to the Accumulation of S1P in Cystic Fibrosis Human Bronchial Epithelial Cells

The role of S1P in Cystic Fibrosis (CF) has been investigated since 2001, when it was first described that the CFTR channel regulates the inward transport of S1P. From then on, various studies have associated F508del CFTR, the most frequent mutation in CF patients, with altered S1P expression in tissue and plasma. We found that human bronchial epithelial immortalized and primary cells from CF patients express more S1P than the control cells, as evidenced by mass spectrometry analysis. S1P accumulation relies on two- to four-fold transcriptional up-regulation of SphK1 and simultaneous halving of SGPL1 in CF vs. control cells. The reduction of SGPL1 transcription protects S1P from irreversible degradation, but the excessive accumulation is partially prevented by the action of the two phosphatases that are up-regulated compared to control cells. For the first time in CF, we describe that Spns2, a non-ATP dependent transporter that normally extrudes S1P out of the cells, shows deficient transcriptional and protein expression, thus impairing S1P accrual dissipation. The in vitro data on CF human bronchial epithelia correlates with the impaired expression of Spns2 observed in CF human lung biopsies compared to healthy control.

Vitreous composition modification after transpalpebral electrical stimulation of the eye: Biochemical analysis

Electrical stimulation (ES) of the eye represents a therapeutic approach in various clinical applications ranging from retinal dystrophies, age-related macular degeneration, retinal artery occlusion and nonarteritic ischemic optic neuropathy. In clinical practice, ES of the eye is mainly performed with a transcorneal or transpalpebral approach. These procedures are non-invasive and well-tolerated by the patients, reporting only minimal and transient adverse events, while serious adverse effects were not observed. Despite the growing literature on animal models, only clinical parameters have been investigated in humans and few data are available about biochemical changes induced by ES of the eye. The purpose of this study is to investigate the possible mechanism that regulates the beneficial effects of ES on retinal cells function and survival in humans. 28 patients undergoing pars plana vitrectomy (PPV) for idiopathic epiretinal membrane (iERM) were randomly divided in two groups: 13 patients were treated with transpalpebral ES before surgery and 15 underwent surgery with no prior treatment. Vitreous samples were collected for biochemical analysis during PPV. ES treatment leads to a reduction in the vitreous expression of both proinflammatory cytokines, namely IL-6 and IL-8, and proinflammatory lipid mediators, such as lysophosphatidylcholine. Indeed, we observed a 70% decrease of lysophosphatidylcholine 18:0, which has been proven to exert the greatest proinflammatory activities among the lysophosphatidylcholine class. The content of triglycerides is also affected and significantly decreased following ES application. The vitreous composition of patients undergoing PPV for iERM displays significant changes following ES treatment. Proinflammatory cytokines and bioactive lipid mediators expression decreases, suggesting an overall anti-inflammatory potential of ES. The investigation of the mechanism by which this treatment alters the retinal neurons leading to good outcomes is essential for supporting ES therapeutic application in various types of retinal diseases.

Sample size estimation in locomotion kinematics and electromyography for statistical parametric mapping

In biomechanics, kinematic and electromyographic data can be represented as one-dimensional (1D) waveforms and compared by using 1D hypothesis tests. These statistical techniques are increasingly applied in the study of locomotion. However, although widely agreed as a key step to obtain reliable and replicable findings, no a priori sample size estimation is usually conducted. This can also be done in 1D tests by calculating the statistical power - i.e., the probability of rejecting the null hypothesis when it is false - by using statistical parametric mapping. With the present study we characterised the parameters needed to estimate sample size in locomotion, and how they impact on statistical power in 1D tests. First, noise and signal in kinematics and electromyography were defined using experimental data on locomotion in physiological and pathological participants. Then, 1D power analysis was performed in representative conditions, and a dataset of tabulated sample sizes was generated. Kinematic and electromyographic data showed a smooth Gaussian noise, with amplitude and full-width-at-half-maximum depending on the physiological or pathological condition, and the considered joint or muscle. Given a certain noise, statistical power increased i) with greater signal amplitude and signal full-width-at-half-maximum, ii) when setting a region of interest and iii) when using a paired (vs. unpaired) study design. The present work provides initial benchmarks for appropriate sampling in 1D hypothesis testing, meant to evaluate statistical power in 1D tests and assists sample size estimation in studies on locomotion.

Usefulness of myocardial work assessment for the understanding of mechanisms underlying sacubitril/valsartan efficacy in patients with heart failure and reduced ejection fraction

Funding Acknowledgements

Type of funding sources: None.

Background

 Sacubitril/valsartan has shown the ability in reducing the risk of death and of hospitalization in patients with HF (heart failure) and is recommended in patients with heart failure with reduced ejection fraction (HFrEF) who remain symptomatic despite conventional therapies. Strain imaging derived myocardial work (MW) is an emerging tool for the evaluation of left ventricular (LV) mechanics by incorporating both systolic deformation and afterload burden in the analysis.

Aim of the study

To evaluate in a prospective fashion the impact of sacubitril/valsartan therapy in HF patients on MW derived parameters in relation with standard echocardiographic indices.

Methods

We recruited thirteen HF patients with indication to sacubitril/valsartan therapy according to current guidelines. Sacubitril/valsartan therapy titrated at the maximum tolerated dose. A comprehensive echo-Doppler exam, including speckle tracking derived assessment of global longitudinal strain (GLS) (in absolute value), was performed before and after a three months therapy with sacubitril/valsartan. Parameters of MW such as global work index (GWI), global constructive work (GCW) global wasted work (GWW) and global work efficiency (GWE) were calculated according to standardized procedures. Patients with more than mild aortic and mitral stenosis and/or regurgitation were excluded. Other exclusion criteria included permanent and/or persistent atrial fibrillation and inadequate echo images.

Results

The 13 patients (M/F = 11/2, age: 57 ± 8.2 years, aetiology: idiopathic in 3 patients, ischaemic in 7 patients and chemotherapy related cardiotoxicity in 3 patients, NYHA Class: II in 7 and III in 6 patients). All patients tolerated sacubitril/valsartan therapy. After the three months therapy an improvement of  LVEF (from 32.3 ± 2% to 36.2± 6%, p = 0.015), GLS (from 9.8 ± 1% to 11.6 ± 2%, p = 0.019), GWI (from 845.0 ± 175.0 mmHg% to 1091.6 ± 336.8 mmHg%, p = 0.003), GCW (from  993.4± 211.6 mmHg% to 1262.7 ± 404 mmHg%, p = 0.002) and GWE (from 77 ± 11% to 81 ± 10%, p = 0.002) was observed, without significant changes in GWW (from 190 ± 121 mmHg% to 211 ± 145 mmHg%, p = 0.307). We also found a positive correlation between the magnitude of LVEF improvement and the baseline values of GCW (r = 0.66, p = 0.014). This relation remained significant even after adjusting for the extent of systolic blood pressure reduction (r = 0.54, p = 0.033).

Conclusion

Three months sacubitril/valsartan therapy significantly improves standard and advanced indices of LV systolic function. This improvement is due to the increase of constructive work more than to the reduction of wasted work and the increase of LVEF can be predicted by the global constructive work levels at baseline. MW assessment may help to understand the mechanisms underlying the sacubitril/valsartan therapy efficacy in HF patients.

Abstract Figure.

COVID-19 lockdown: Physical activity, sedentary behaviour and sleep in Italian medicine students

COVID-19 pandemic led many countries to implement lockdown measures. Italy declared lockdown from 9th March to 3rd May 2020, and universities shifted to online classes. Home confinement could prevent students from achieving the physical activity and sleep levels recommended for their psychophysical health, and medicine students are already known to be at risk of inactivity and reduced sleep due to their time-consuming curricula. This study aimed at describing medicine students' behaviours during lockdown and comparing them with pre-lockdown data and current recommendations. A cross-sectional questionnaire survey was conducted among 6th-year Italian medicine students (n = 714; age=25 ± 2 y; female: 62%; male: 38%) in October-November 2019. The same survey was repeated in 6th-year students during lockdown (n = 394; age=25 ± 2 y; female: 73%; male: 27%), and extended to 1st-5th year (total 1st-6th-year sample during lockdown: n = 1471; age=23 ± 2 y; female: 70%; male: 30%). International Physical Activity Questionnaire Short Form (IPAQ) and selected questions from Pittsburgh Sleep Quality Index were administered to evaluate physical activity, sitting and sleep time. Decreased physical activity, and increased sitting and sleep time were observed from pre- to during lockdown in 6th-year students (p<0.01). 1st-6th-year students featured 10 [8-12] hours sitting (median [Q1-Q3]) and an IPAQ score of 1170 [400-2348] MET-min/week. Even participants with higher physical activity featured high sitting time. Sleeping less than recommended (<7 h/night) was associated with more sitting time and less energies to perform daily activities. Strategies fostering compliance with current guidelines for physical activity, sedentary behaviour and sleep should be implemented, especially in case of a repeated or intermittent lockdown.Highlights During lockdown, medicine students reduced their total physical activity and increased sedentary behaviour.Walking time was reduced in favour of increased higher-intensity physical activity. However, total metabolic expenditure was lower than before lockdown.Before lockdown students slept less than the recommended 7 hours per night, but they increased sleep time during lockdown.Medical schools should promote education on physical activity and sleep, since it improves the health of students, doctors and patients. This is especially valuable in case of repeated lockdown.

Impact of diastolic blood pressure on speckle tracking derived myocardial work components in a population of normotensive and untreated hypertensive patients

Background

Arterial hypertension deeply influences left ventricular (LV) mechanics and global longitudinal strain (GLS). The effect of blood pressure (BP), in particular systolic BP burden, on speckle tracking derived myocardial work (MW) was demonstrated in both hypertensive and healthy subjects.

Purpose

Aim of our study was to evaluate the impact of diastolic BP (DBP) on MW components in a population of newly-diagnosed, never treated hypertensive patients and healthy subjects.

Methods

The study population included 105 newly-diagnosed, never treated hypertensive patients (M/F= 62/43; age=46.1±13.0 years, BP=145.1±10/89.8±7.4 mmHg), and 105 healthy normotensive subjects (BP=121.6±9.8/73.7±7.4mmHg), matched for age and sex. All participants underwent standard echo exam, including GLS evaluation (in absolute value). Cuff BP was employed as a surrogate of LV peak pressure for the assessment of global work index (GWI), global constructive work (GCW), global wasted work (GWW) and global work efficiency (GWE). Exclusion criteria were diabetes mellitus, coronary artery disease, overt heart failure, valve heart disease, primary cardiomyopathies, atrial fibrillation and inadequate echo imaging. The study population was divided into two groups according to DBP threshold of normalcy defined by 2018 ESH/ESC guidelines: the first group including individuals with normal DBP (n=135, DBP&lt;90mmHg) and the second group including patients with abnormal DBP (n=75, DBP ≥90 mmHg).

Results

The two groups were comparable for sex prevalence, age and heart rate. Body mass index (BMI), systolic and mean BP were higher in the group with abnormal DBP (all p&lt;0.0001). Among echo data, no significant intergroup difference was found in LV mass index, relative wall thickness, ejection fraction and diastolic parameters. GLS was lower in patients with abnormal DBP (20.4±1.9 vs. 22.1±2.1%, p&lt;0.0001). GWI (2443.0±403.1 vs. 2277.3±359.6 mmHg%, p&lt;0.002), GCW (2733.5±406.0 vs. 2556.9±405.6 mmHg%, p=0.003) and GWW (112.8±84.4 vs. 76.8±45.1 mmHg%, p&lt;0.0001) were significantly higher in patients with abnormal DBP, whereas GWE (95.3±2.8 vs. 96.2±1.7%, p&lt;0.002) was lower in this group. In the pooled population, DBP was positively related to GWI, GCW (both r=0.30, p&lt;0.0001) and GWW (r=0.26, p&lt;0.0001), while negatively correlated with GLS (r=−0.37, p&lt;0.0001) and GWE (r=−0.21, p&lt;0.002). By separate multiple linear regression analyses, GWI (β=0.45, p&lt;0.0001), GCW (β=0.47, p&lt;0.0001), GWW (β=0.20, p=0.007) and GWE (β=−0.15, p&lt;0.05) were all independently associated with DBP, after adjusting for male sex, age, BMI, heart rate, GLS and E/e' ratio.

Conclusions

In a population of untreated hypertensive patients and healthy subjects, increased DBP affects longitudinal function and MW. In particular, elevated diastolic BP induces an increase of wasted work which is only partially balanced by the increased constructive work, thus provoking a clear reduced efficiency of myocardial mechanics.

Figure 1

Funding Acknowledgement

Type of funding source: None

Right ventricular dysfunction parallels left ventricular functional involvement in women with breast cancer experiencing subclinical cardiotoxicity

Background

Cancer therapy related cardiac toxicity disease (CRCTD) of the left ventricle (LV)can influence the outcome of oncologic patients. Little is known on CRCTD related right ventricular (RV)dysfunction even though RV involvement has been proven to be a remarkable prognosticator in heart failure.

Purpose

To analyse parallel changes in LV and RV function occurring during the course of cancer therapy in women affected by breast cancer by using both standard and speckle tracking echocardiography.

Methods

Fifty Her-2 positive breast cancer women (age = 53.6±11.7 years) underwent sequential cancer therapy protocol including anthracycline (ANT) epirubicine + cyclophosphamide (4 cycles) followed by a total amount of 18 cycles with trastuzumab (TRZ) + paclitaxel. A complete echo-Doppler exam, including LV and RV global longitudinal strain (GLS)as well as RV septal and free wall longitudinal strain (SLS and FWLS respectively) assessment, was performed at baseline, after ANT end and after TRZ completion. Patients with overt heart failure and LV ejection fraction &lt;50%, coronary artery disease,atrial fibrillation, hemodinamically significant valve disease and inadequate echo were excluded. Overt CRCTD was defined according guidelines and both subclinical LV and RV CRCTD as a LV and RV GLS drop from baseline &gt;15%.

Results

None of the patients experienced overt CTCRD but 6 patients (14%) showed subclinical LV dysfunction and 33 (66%) had a significant drop of RV longitudinal function.The comparison of standard echo-Doppler exam at baseline and after ANT and TRZ completion did not show significant changes of LV and RV systolic and diastolic parameters. Conversely, a progressive significant reduction of RV GLS (p&lt;0.002 after TRZ), SLS and FWLS and, with a lower extent, of LV GLS (p&lt;0.02 after TRZ) was observed after ANT and TRZ completion (Figure). Percentage reduction in RV GLS (DRV GLS) from baseline to ANT end correlated with LV GLS both at EC end (r=−0.40, p=0.006) and after TRZ completion (r=−0.62, p&lt;0.0001).

Conclusions

Detrimental cardiac effects of cancer therapy involve both LV and RV systolic longitudinal function. Progressive RV dysfunction is evident through ANT and TRZ treatment. Early RV dysfunction parallels LV involvement and predicts subsequent LV subclinical dysfunction. A comprehensive LV and RV longitudinal function assessment might better predict the onset of CRCTD in breast cancer patients.

LV and RV strain during cancer therapy

Funding Acknowledgement

Type of funding source: None

433 Independent impact of metabolic syndrome on left ventricular longitudinal dysfunction in type 2 diabetes mellitus

Background

The risk of cardiovascular (CV) disease in type 2 diabetes mellitus (T2DM) is highly heterogeneous and an adequate risk stratification is needed. CV risk mainly depends on concomitant risk factors, combined in the metabolic syndrome (MetS). Echocardiography is an useful tool for diagnosis of cardiac organ damage and CV risk stratification in T2DM.

Purpose

To investigate the effects of MetS on left ventricular (LV) structure and function in patients with T2DM with normal LV ejection fraction (LVEF) and without overt coronary artery disease (CAD) and heart failure symptoms/signs.

Methods

We prospectively recruited 384 consecutive, uncomplicated T2DM patients. All patients underwent clinical exam, blood sampling and complete echo-Doppler exam, including determination of 2D-echo derived global longitudinal strain (GLS). LV mass index ≥45 g/m^2.7 in women and ≥49 g/m^2.7 in men was used to characterize LV hypertrophy. LV longitudinal dysfunction was assumed for GLS &lt; 20% in absolute values. LV diastolic dysfunction was identified according to 2016 ASE/EACVI recommendations. MetS was defined according to NCEP-ATP III criteria. Significant CAD including previous myocardial infarction, LV systolic dysfunction (= LVEF &lt;50%), hemodinamically significant valvular heart disease, primary cardiomyopathies, permanent atrial fibrillation, glomerular filtration rate &lt;30 ml/min and inadequate echo images were exclusion criteria. The study population was divided according to presence of MetS.

Results

66% of the patients (254/384) met the criteria for MetS diagnosis. They had comparable age and heart rate with controls. Diabetic patients with MetS had higher glycated haemoglobin (HbA1c) (7.2 ± 1.3 vs. 6.9 ± 1.0%, p = 0.023) and uric acid (5.5 ± 1.4 vs. 4.9 ± 1.3 mg/dl, p = 0.001) than those without, and lower glomerular filtration rate (69.5 ± 15.0 vs 74.0 ± 12,1 ml/min, p = 0.004). MetS patients showed a higher LV mass index (p &lt; 0.0001) and a greater prevalence of both LV hypertrophy (31.9 vs 12.5%, p &lt; 0.0001) and diastolic dysfunction (52.6 vs. 32.8%, p = 0.007) (Figure). T2DM patients with MetS also had lower GLS (20.6 ± 2.1 vs. 21.9 ± 2.2%, p = 0.001), with a greater prevalence of LV longitudinal dysfunction (38.2 vs. 24.7%, p = 0.049) (Figure). After adjusting for age, T2DM duration, sex, HbA1c, uric acid, LV mass index and LV diastolic dysfunction by a multiple regression analysis in the pooled population, GLS reduction was independently associated with MetS (β coefficient = -0.184, p &lt; 0.02) and LV mass index (β= -0.94, p = 0.04).

Conclusion

In patients with T2DM, the presence of MetS induces a greater prevalence not only of LV hypertrophy and diastolic dysfunction but also of LV longitudinal deformation impairment. GLS reduction in diabetic patients is associated with MetS independently of confounders including glycemic control and diabetic duration.

Abstract 433 Figure. Rate of LV alterations according to MetS

P291 Additional value of myocardial work in detecting subclinical systolic dysfunction in patients with bicuspid aortic valve and left ventricular hypertrophy

Background

An impairment of speckle tracking derived left ventricular (LV) global longitudinal strain (GLS) has been observed in patients with bicuspid aortic valve (BAV) and referred to abnormalities of aortic elasticity properties. The impact of LV mass on myocardial deformation has still not been investigated. This issue can be now better addressed by myocardial work software, which incorporates both deformation and hemodynamic load in the analysis.

Aim of the study

To analyse the impact of both deformation and strain derived myocardial work in BAV patients with and without LV hypertrophy (LVH).

Methods

Sixty-five patients with BAV underwent a comprehensive echo exam, including speckle tracking derived calculation of GLS (in absolute value). Parameters of myocardial work such as global work index (GWI), global constructive work (GCW) global wasted work (GWW) and global work efficiency (GWE) were measured according to standardized procedures. Patients with reduced LV ejection fraction and with more than mild aortic stenosis and/or regurgitation were excluded. Other exclusion criteria included coronary artery disease, concomitant valvular heart disease, heart failure, primary cardiomyopathies, permanent and/or persistent atrial fibrillation and inadequate echo images. BAV patients were divided according to presence of LVH: 10 with LVH (LV mass index &gt;47 g/m^2.7 in women and &gt;50 g/m^2.7 in men) and 55 without LVH.

Results

The two groups were comparable for sex, age and heart rate whereas systolic blood pressure (p = 0.006) and pulse pressure (p = 0.002) were higher in patients with LVH, who also had higher relative diastolic wall thickness (p &lt; 0.02). No significant difference in ejection fraction (p = 0.56), transmitral E/A ratio (p = 0.504) and E/e" (p = 0.311) was found between the two groups. GLS (19.1 ± 2.5 in LVH group and. 20.0 ± 2.4% in patients without LVH, p = 0.290), GWI (p = 0.356) and GCW (p = 0.396) did not differ significantly whereas GWW was higher (119.5 ± 72.9 vs. 72.3 ± 38.7 mmHg%, p = 0.003) and GWE lower (94.4 ± 3.0 vs. 92.2 ± 1.6%, p = 0.007) in BAV patients with LVH (Figure). In the pooled population, LV mass index was related with GWW (r = 0.26, p = 0.03) and GWE (r=-0.30, p &lt; 0.01) but not with GLS (r=-0.22, p = 0.08). The relation between GWE and LV mass index remained significant even after adjusting for pulse pressure (partial r=-0.28, p &lt; 0.02).

Conclusion

In patients with BAV, LVH plays a detrimental effect on LV systolic function which cannot be identified by ejection fraction and GLS assessment but is unmasked by the application of myocardial work. In presence of LVH, the wasted work of BAV patients is increased and myocardial efficiency is substantially reduced, it being negatively related to LV mass even after adjusting for a raw index of aortic stiffness such as pulse pressure.

Abstract P291 Figure. GLS, GWW and GWE according to LVH

1033 Prominent longitudinal strain involvement of left ventricular basal segments in native hypertensive patients without clear-cut hypertrophy

Background

Left ventricular (LV) global longitudinal strain (GLS) is able to detect an early subclinical dysfunction and it has been demonstrated to be a prognosticator in arterial hypertension. Information of regional longitudinal strain (LS) pattern has not been investigated in this clinical setting.

Purpose

We analyzed regional LV patterns of LS and base-to-apex behaviour of LS in newly diagnosed and never-treated hypertensive patients (HTN) without clear-cut LV hypertrophy (LVH).

Methods

166 HTN (M/F = 107/59; age 43.9 ± 14.3 years, blood pressure [BP] = 146.5± 10.7/90.1 ± 7.5 mmHg) and a control group of 94 healthy subjects (M/F = 58/36; age 41.2 ± 15.0 years) underwent standard echo-Doppler exam, including speckle tracking quantification of regional LS and GLS (considered in absolute values). The average LS of six basal (BLS), six middle (MLS), and six apical (ALS) segments and relative regional strain ratio - RRSR = [ALS/(BLS + MLS)] - were also computed. Exclusion criteria were LVH (LV mass index ≥45 g/m^2.7 in females and ≥49 g/m^2.7 in males), diabetes mellitus, coronary artery disease, overt heart failure, hemodynamically significant valve heart disease, primary cardiomyopathies, atrial fibrillation and inadequate echo imaging.

Results

The two groups were comparable for sex, age, heart rate and LV ejection fraction (EF). Body mass index (BMI), systolic (SBP), diastolic (DBP) and mean BP (MBP) (all p &lt; 0.0001), LV mass index (p = 0.03), relative wall thickness (RWT) (p &lt; 0.02) and E/e’ ratio (p &lt; 0.01) were higher, and GLS lower (21.6 ± 2.0 vs. 22.2 ± 2.1%, p &lt; 0.02) in HTN. By analyzing regional LS, BLS (18.2 ± 2.1% vs. 19.2 ± 2.1%, p &lt; 0.0001) and MLS (20.7 ± 2.0 vs. 21.4 ± 2.1%, p = 0.007) resulted significantly lower in HTN, without significant difference in ALS (26.0 ± 3.6 vs. 25.9 ± 3.8%, p = 0.98). Accordingly, RRSR was higher in HTN (0.67 ± 0.09 vs. 0.64 ± 0.09, p &lt; 0.01). Even after excluding patients with LV concentric remodeling (RWT &gt; 0.42) (n = 34), BLS (p &lt; 0.0001) and MLS (p &lt; 0.002) were again lower and RRSR (p &lt; 0.01) higher in HTN than in controls. In the pooled population, BLS negatively correlated with SBP (r=-0.22), DBP (r=-0.25) and MBP (r=-0.26) (Figure) (all p &lt; 0.0001). By a multiple linear regression analysis, after adjusting for age, sex, BMI and RWT, the association between BLS and MBP remained significant (β coefficient=-0.23, p &lt; 0.0001), with an additional significant impact of male sex (β=-0.33, p &lt; 0.0001) (cumulative R²=0.18, SEE = 1.9%, p &lt; 0.0001).

Conclusions

Besides normal LV EF, GLS is lower in HTN. LS dysfunction involves basal and, with a lower extent, middle myocardial segments, with a compensation of apical segments. RRSR appears to be significantly higher in HTN. These results are even confirmed in hypertensive patients with normal LV geometry. The association of BLS and BP appears to be independent on several confounders. Regional LS pattern might be useful to detect very early LV systolic abnormalities in arterial hypertension.

Abstract 1033 Figure. Relation between MBP and BLS

P1782 Left ventricular deformation proprieties in aortic coarctation: insights from multilayer strain imaging

Background

Patients with coarctation of the aorta (CoA) have proven impaired left ventricular (LV) myocardial deformation that will persist even after successful transcatheter intervention compared to normal controls. However, little is known about layer specific contraction in this clinical setting.

Purpose

To investigate multi-layer longitudinal strain in patients with repaired CoA, compared with a control group of healthy subjects.

Methods

In a case-control study, 13 CoA patients (F/M = 9/4, age = 15.1 ± 4.4 years) and 13 healthy age- and sex-matched controls, underwent a complete echocardiogram, including speckle tracking assessment for quantification of LV transmural global longitudinal strain (GLS), subendocardial longitudinal strain (LSsubendo), subepicardial longitudinal strain (LSsubepi), and myocardial longitudinal strain gradient (LSsubendo - LSsubpepi).

Results

CoA patients had similar blood pressure, heart rate, and body surface area in comparison with healthy controls. The two groups did not differ for ejection fraction and LV diastolic indices. Increased maximal gradient (&gt;20 mmHg) in descending aorta was found in 9 (69.2%) CoA patients. In CoA population, 5 (38.5%) had LV concentric remodeling (RWT &gt; 0.42) and 2 (15.4%) LV hypertrophy (Z score &gt;2.0). LV mass index (92.4 ± 31.1 vs. 60.9 ± 12.5 g/m^2.7, p = 0.002), septal wall thickness (8.7 ± 2.0 vs 6.6 ± 0.9 mm p = 0.002), posterior wall thickness (8.2 ± 1.7 vs. 6.6 ± 1.4 mm, p = 0.02) and RWT (0.38 ± 0.06 vs. 0.27 ± 0.08, p &lt; 0.001) were greater in CoA patients. By multi-layer deformation analysis, GLS (21.2 ± 1.9 vs. 22.9 ± 1.4%, p &lt; 0.01), LSsubepi (19.3 ± 1.6 vs. 21.0 ± 1.6%, p &lt; 0.01), LSsubendo (22.9 ± 1.8 vs. 25.4 ± 1.9%, p = 0.003) and longitudinal strain gradient (3.6 ± 1.1 vs. 4.7 ± 1.1, p &lt; 0.02) were lower in CoA patients than in healthy controls. Separate sub-analyses in patients without LV hypertrophy, substantially confirmed the same results: GLS 20.9 ± 1.6 vs. 22.8 ± 0.9%, p = 0.004; LSsubepi 19.0 ± 1.4 vs. 21.1 ± 1.3%, p = 0.004; and LSsubendo 22.4 ± 1.2 vs. 25.3 ± 1.4%, p &lt; 0.0001; strain gradient 3.4 ± 1.0 vs. 4.6 ± 1.1, p = 0.02. Notably, LSsubepi (18.6 ± 1.4 vs. 20.6 ± 1.0%, p = 0.03) and, with greater significance, LSsubendo (22.1 ± 1.1 vs. 24.7 ± 1.8%, p &lt; 0.0001) were lower in CoA patients with increased aortic gradient versus those without significant gradient increase.

Conclusions

In CoA patients, layer specific strain imaging highlights an impairment of LV longitudinal deformation, which mainly involves LSsubendo and causes reduction of longitudinal strain gradient. This preferential impairment of subendocardium is particularly evident in patients with residual aortic gradient and is independent of LV hypertrophy.

Abstract P1782 Figure. Multilayer strain in CoA vs. controls

P297 Left atrial volume index is the best predictor of post-capillary pulmonary hypertension in patients with pure mitral valve stenosis

Background

Mitral stenosis (MS) is characterized by a reduced mitral valve area (MVA) and an increased transmitral pressure gradient, with direct consequences on left atrial (LA) remodelling and pulmonary arterial systolic pressure (PASP). Post-capillary pulmonary hypertension (PH) has a main impact on the outcome in patients with MS.

Purpose

To evaluate determinants of post-capillary PH in patients with pure MS by using a combined approach of standard and advanced echocardiography.

Methods

From January 2018 to January 2019, 52 consecutive patients with MS were enrolled. Concomitant hemodynamically significant valve heart disease, primary PH, coronary artery and congenital heart diseases, primary cardiomyopathies, prosthetic valves and permanent/persistent atrial fibrillation were exclusion criteria. Twenty-three "pure" MS were selected (age: 63.9 ± 11.6 years, F/M= 17/6). Twenty-three healthy controls, matched by age and sex, were recruited as the control group. All participants underwent a complete echocardiographic examination, including determination of left ventricular ejection fraction (LVEF), speckle tracking derived global longitudinal strain (GLS, in absolute values), LA volume index (LAVi) and PASP. MS severity was assessed by continuous wave Doppler derived mean transmitral pressure gradient (MPG), pressure half time (PHT) and functional mitral valve area (MVA). Data were analysed offline by a dedicated workstation.

Results

No significant difference of body mass index, systolic and diastolic blood pressure was found between the two groups, while heart rate was higher in MR (p &lt; 0.0001). In the pooled MS population, MPG was 5.7 ± 2.4 mmHg, PHT 127.7 ± 26.9 msec and MVA 1.76 ± 0.36 cm². Twelve patients (52.1%) had mild MS, 10 (43.5%) moderate MS and one (4.3%) severe MS. Patients with MS had larger LA volumes (LAVi = 45.0 ± 12.7 vs. 28.3 ± 7.3 ml/m², p &lt; 0.0001), higher PASP (36.4 ± 8.9 vs. 30.4 ± 6.7 mmHg, p &lt; 0.01), lower LVEF (58.5 ± 6.1 vs. 66.0 ± 3.5%. p &lt; 0.0001) and lower GLS (18.8 ± 4.6 vs. 21.7 ± 2.5%, p &lt; 0.01) than the healthy controls. By analyzing the MS group, LAVi had a significant univariate relation with MPG degree (r = 0.69, p &lt; 0.002). PASP correlated with LAVi (r = 0.60, p = 0.003) and MPG (r = 0.51, p &lt; 0.01) but not with PHT (r = 0.28, p = 0.54) and functional MVA (r=-0.31, p = 0.33). By a multlinear regression analysis, including heart rate, MPG, LVEF and GLS as potential determinants, LAVi (standardized beta coefficient =0.65, p= &lt;0.02) and GLS (beta =-0.62, p = 0.03) were both independently associated with PASP degree, whereas the association of MPG and PASP was not significant (cumulative R²=0.47, SEE = 5.9 mmHg, p &lt; 0.01) in the MS group.

Conclusions

In patients with pure MS, by using a multi-parametric echocardiographic approach, LA dilation appears to be the best predictor of post-capillary PH, independent on the magnitude of LV systolic dysfunction and valvular disease severity. Particular care should be devoted to determine LA size in this clinical setting.

Abstract P297 Figure. Relation between LAVi and PASP in MS

Characteristics and circumstances of falls in hip fractures

Osteoporosis is a chronic disease characterized by a loss of bone mass and deterioration of bone microstructure that lead to a greater risk of fragility fractures. Fall is generally the main cause of fractures. Hip fractures are the most common ones and are usually correlated to a greater morbidity and mortality. The aim of our observational study was to evaluate, among patients with hip fragility fracture, characteristics and circumstances of falls. We conducted a national epidemiological survey, involving 80 physiatrists. They were asked to collect data on patients over 55 years of age who underwent a fragility fracture in the 12 months prior to recruitment. For each patient they had to fill a form including questions on different aspects of patients' medical history: age, gender, reason for the visit, type of fracture, number of falls in the last year and the year before the fall. Among 419 patients who sustained hip fracture, 70 had experienced a fall, while 119 were incurred in more falls in the 12 months before the fracture. In most people of our cohort, hip fracture was caused by a fall that occurred on the side during the morning.

Deregulation of the mitochondrial apoptotic machinery and development of molecular targeted drugs in acute myeloid leukemia

Apoptosis plays a key role in the control of rapidly renewing tissues, such as the hematopoietic system and leukemia cells invariably have abnormalities in one or more apoptotic pathways, determining a survival advantage of these cells and the development of drug resistance. These defects are also frequently associated with a low rate of response to standard chemotherapy and with a poor survival in acute myeloid leukemia (AML). The major form of apoptosis proceeds through the mitochondrial pathway, with the mitochondrial outer membrane permeabilization, leading to the release of proteins normally found in the space between the inner and outer mitochondrial membranes (cytochrome C, AIF and others). Higher levels of anti-apoptosis proteins bcl-2, bcl-x(L), Mcl-1 block permeabilization of the membrane and are reported in AML patients presenting a poor outcome. On the contrary, activated pro-apoptotic bax or bad proteins allow this permeabilization and are correlated to a good prognosis in AML. Defects in the mitochondrial pathway induce multidrug-resistance and confer important prognostic information in AML. High ratios of bcl-2 to bax protein confer a poor prognosis with decreased rates of complete remission and overall survival. The prognostic information from the ratio of the proteins is greater than bcl-2 levels alone. Recently, we confirmed the impressive impact of the bax/bcl-2 ratio, determined by flow cytometry, on AML prognosis (complete remission and overall survival) in 255 AML patients. Bcl-2 down regulation might lower the apoptotic threshold of leukemic cells and, through this mechanism, favor response to chemotherapy. Phase II studies of oblimersen (antisense Bcl-2), cytarabine and daunorubicin or oblimersen plus gentuzumab, a cytotoxic antibody directed against CD33+ cells in relapsed AMLs, showed promising results. Defects in apoptosome proteins, such as APAF-1, are frequent in AML and treatment with 5-aza-2'-deoxycytidine, a specific inhibitor of DNA methylation, restored APAF-1 expression in leukemic cells. In conclusion, targeted therapies that are designed to induce apoptosis in leukemic cells, are the most promising anti-leukemia strategies. The elucidation of the apoptotic machinery and of its defects in AML lays the basis for developing new drugs able to trigger apoptosis and overcome therapy resistance.

Activator protein-2 overexpression accounts for increased insulin receptor expression in human breast cancer

Various studies have shown that the insulin receptor (IR) is increased in most human breast cancers, and both ligand-dependent malignant transformation and increased cell growth occur in cultured breast cells overexpressing the IR. However, although numerous in vivo and in vitro observations have indicated an important contributory role for the IR in breast cancer cell biology, the molecular mechanisms accounting for increased IR expression in breast tumors have not previously been elucidated. Herein, we did immunoblot analyses of nuclear protein from cultured breast cancer cells and normal and tumoral tissues from breast cancer patients combined with promoter studies by using a series of human wild-type and mutant IR promoter constructs. We provide evidence that IR overexpression in breast cancer is dependent on the assembly of a transcriptionally active multiprotein-DNA complex, which includes the high-mobility group A1 (HMGA1) protein, the developmentally regulated activator protein-2 (AP-2) transcription factor and the ubiquitously expressed transcription factor Sp1. In cultured breast cancer cells and human breast cancer specimens, the expression of AP-2 was significantly higher than that observed in cells and tissues derived from normal breast, and this overexpression paralleled the increase in IR expression. However, AP-2 DNA-binding activity was undetectable with the IR gene promoter, suggesting that transactivation of this gene by AP-2 might occur indirectly through physical and functional cooperation with HMGA1 and Sp1. Our findings support this hypothesis and suggest that in affected individuals, hyperactivation of the AP-2 gene through the overexpression of IR may play a key role in breast carcinogenesis.

PI3K mediates protection against TRAIL-induced apoptosis in primary human melanocytes

Melanocytes are cells of the epidermis that synthesize melanin, which is responsible for skin pigmentation. Transformation of melanocytes leads to melanoma, a highly aggressive neoplasm, which displays resistance to apoptosis. In this report, we demonstrate that TNF-related apoptosis-inducing ligand (TRAIL), which was thought to kill only transformed cells, promotes very efficiently apoptosis of primary human melanocytes, leading to activation of caspases 8, 9 and 3, and the cleavage of vital proteins. Further, we show that stem cell factor (SCF), a physiologic melanocyte growth factor that activates both the phosphatidyl-inositol-3 kinase (PI3K) and the extracellular regulated kinase (ERK) pathways, strongly protects melanocytes from TRAIL and staurosporine killing. Interestingly, inhibition of PI3K or its downstream target AKT completely blocks the antiapoptotic effect of SCF, while inhibition of ERK has only a moderate effect. Our data indicate that protection evoked by SCF/PI3K/AKT cascade is not mediated by an increase in the intracellular level of FLIP. Further, only a sustained PI3K activity can protect melanocytes from apoptosis, thereby indicating that the PI3K/AKT pathway plays a pivotal role in melanocyte survival. The results gathered in this report bring new information on the molecular mechanisms involved in primary melanocyte apoptosis and survival that would help to better understand the process by which melanomas acquire their resistance to apoptosis.

T and B leukemic cell lines exhibit different requirements for cell death: correlation between caspase activation, DFF40/DFF45 expression, DNA fragmentation and apoptosis in T cell lines but not in Burkitt's lymphoma

The execution phase of apoptosis occurs through the activation and function of caspases which cleave key substrates that orchestrate the death process. Here, we have compared the sensitivity of various T and B cell lines to death receptor or staurosporine-induced apoptosis. First, we found a lack of correlation between death receptor expression and sensitivity to Fas or Trail. By contrast, a correlation between caspase activation, DNA fragmentation and cell death in T cell lines was evidenced. Among T cells, CEM underwent apoptosis in response to CH11 but were resistant to Trail in agreement with the absence of Trail receptors (DR4 and DR5) on their surface. The B cell line SKW 6.4 was sensitive to CH11 and staurosporine but resistant to Trail. As B cell lines expressed significant levels of DR4 and DR5, resistance to Trail in SKW 6.4 is likely due to the expression of the decoy receptor DcR1. Burkitt's lymphoma such as RPMI 8866 and Raji did not exhibit DNA fragmentation in response to CH11, Trail or staurosporine but showed long-term caspase-dependent loss of viability upon effector treatment. The B cell lines used in this study express very weak or undetectable levels of DFF40 and relatively high levels of DFF45. Interestingly, cytosolic extracts from RPMI 88.66 but not other B lymphoma exhibit altered levels of cytochrome c-dependent caspase activation. Taken together, our results show that: (1) death receptor expression does not correlate with sensitivity to apoptosis; (2) the very low ratio of DFF40 vs. DFF45 is unlikely to explain by itself the lack of DNA fragmentation observed in certain B cell lines; and (3) a defective cytochrome c-dependent caspase activation might account at least in part for the insensitivity of certain Burkitt's lymphoma (RPMI 88.66) to apoptosis. Thus it seems that resistance of Burkitt's lymphoma to apoptosis is not governed by a general mechanism, but is rather multifactorial and differs from one cell line to another.

Cleavage of Fyn and Lyn in their N-terminal unique regions during induction of apoptosis: a new mechanism for Src kinase regulation

The members of the Src kinase family are expressed in a wide variety of tissues, but some of them such as Blk, Hck, Fgr, Lck and Lyn are found primarily in hematopoietic cells. In the present study, we have undertaken experiments to test whether Src kinase cleavage and relocation is a general mechanism during induction of apoptosis. Our results indicate that Fyn and Lyn are efficiently cleaved in their unique region in hematopoietic cells undergoing apoptosis. Fyn cleavage occurred in Fas-stimulated Jurkat T cells but Fyn and Lyn were also processed in the SKW6.4 B cell line. Inhibition of caspases by Z-VAD-fmk or Ac-DEVD-CHO totally prevented Fyn and Lyn cleavage in both intact cells and in vitro. Fyn and Lyn but not Lck, Src and Hck were processed in vitro by human recombinant caspase 3 and by cellular extracts prepared from Fas-stimulated cells. Single mutation of Asp 19 or Asp 18 in the unique N-terminal domains of Fyn and Lyn respectively abolished their cleavage and relocation into the cytoplasm of apoptotic cells. When immunoprecipitated from COS cells N-terminal deleted Src kinases exhibited increased enzymatic kinase activity toward enolase. Thus, cleavage of Fyn and Lyn during induction of apoptosis represents a new mechanism for the regulation of Src kinases that may have important functional and physiological consequences.

Differential requirements for ERK1/2 and P38 MAPK activation by thrombin in T cells. Role of P59Fyn and PKCε

Activation of the mitogen-activated protein kinase (MAPK) cascade is a well documented mechanism for the G-protein-coupled receptors. Here, we have analysed the requirements for ERKs and p38 MAPK activation by thrombin in Jurkat T cells. We show that thrombin-mediated ERKs activation requires both PTK and PKC activities, whereas p38 MAPK activation is dependent only on PTKs. Thrombin-induced ERK and p38 MAPK activation was more pronounced in p56Lck deficient cells indicating that this PTK exerts a negative control on MAPK activity. Accordingly, overexpression of p50 Csk a kinase that inactivates p56Lck induced constitutive activation of ERKs. Requirement for a Src kinase was evidenced by expression of a constitutively active form of p59Fyn in Jurkat cells. Besides its effect on tyrosine phosphorylation events, thrombin also triggered a rapid and robust redistribution of PKCepsilon and delta from the cytosol to the membrane. Expression of constitutively active and dominant negative PKCepsilon demonstrates the pivotal role of this PKC isoform in ERKs activation by thrombin. These data are consistent with a model where thrombin induces ERK activation via both PKC-dependent and independent pathways, whereas p38 MAPK activation requires only PTKs. The PKC-independent pathway requires Src kinases other than p56Lck more likely p59Fyn, while the PKC-dependent mechanism depends on PKCepsilon

A Jurkat T cell variant resistant to death receptor-induced apoptosis. Correlation with heat shock protein (Hsp) 27 and 70 levels

Ligation of Fas induces an apoptotic program in Jurkat cells (Jd). We describe a Jurkat T cell variant (Jr) which shows total resistance to Fas-mediated apoptosis but which exhibits sensitivity to non-death-receptor pro-apoptotic stimuli such as staurosporine. Resistance to Fas-induced apoptosis in Jr cells is correlated with high expression of Hsps. A prior heat-shock increases Hsp27 and 70 expression and protects Jd and Jr cells from Fas- and staurosporine-induced apoptosis. Staurosporine, but not the anti-Fas antibody CH11, abrogates constitutive Hsp70 expression at 37 degrees C and staurosporine also inhibit Hsp27 expression in Jd and Jr cells at 42 degrees C. These data suggest that constitutive expression of Hsp27 inhibits Fas-mediated apoptosis, but only induced expression of Hsp70 can protect T cells from staurosporine-induced apoptosis. Thus, Hsp27 could play a role in the regulation of death receptor-mediated apoptosis, while Hsp70 could regulate mitochondrial-dependent cell death.

Helicobacter pylori lipopolysaccharide hinders polymorphonuclear leucocyte apoptosis

A prominent histologic feature of Helicobacter pylori infection is a dense infiltration of polymorphonuclear leukocytes (PMNL) in gastric mucosa. H. pylori lipopolysaccharide (LPS) has been recognized as a primary virulence factor evoking acute mucosal inflammatory reaction. Previous works have shown that H. pylori LPS immunologic activities are lower than those of enterobacterial LPS. However, the effect of H. pylori LPS on spontaneous PMNL apoptosis, and mechanisms by which this H. pylori LPS may promote PMNL survival remain to be established. In this study, we investigated, by both morphologic and biochemical approaches, the action of H. pylori LPS on PMNL apoptosis in vitro, using broth culture filtrates (BCF) of H. pylori strains with different genotypes. We found that BCF from H. pylori caused a significant delay in spontaneous PMNL apoptosis and this delay was independent of the VacA, cag pathogenicity island and urease status. We demonstrated that LPS in BCF is responsible for this effect because it was abrogated by the LPS antagonist B287 (a synthetic analog of Rhodobactersphaeroides lipid A). Moreover, BCF from H. pylori induced P42/44MAP kinase activation in PMNL. Similar results were obtained with BCF of an Escherichia coli strain. Taken together these data suggest that longer survival of PMNL induced by H. pylori LPS may increase gastric epithelium injury in H. pylori-associated diseases.

Cleavage of the serum response factor during death receptor-induced apoptosis results in an inhibition of the c-FOS promoter transcriptional activity

The c-FOS protooncogene is rapidly induced by a wide variety of extracellular stimuli including mitogenic signals. Regulation of c-FOS expression is tightly dependent on the serum response element localized within its promoter. Two transcription factors, the serum response factor (SRF) and the ternary complex factor, bind to the serum response element and play a key role in the regulation of the c-FOS promoter activity. In the present study, we show that two death effectors (CH11 and TRAIL) severely impaired the transcriptional activity of the c-FOS promoter in Jurkat T cells. This inhibition can be accounted for by the specific cleavage by caspase 3 of the SRF both in vitro and in vivo, since acetyl-DEVD-aldehyde prevented SRF cleavage and abolished the inhibitory effect of CH11 and TRAIL on the c-FOS promoter activity. Moreover, phorbol myristate acetate, a potent anti-apoptotic effector, was found to protect SRF completely from cleavage by caspase 3 and also to prevent the inhibition of the c-FOS promoter activity by death effectors. Survival factors play an essential function in the regulation of cell growth mainly by regulating the expression of immediate early gene such as c-FOS. In this line, cleavage of SRF at the onset of apoptosis could abrogate the ability of the cell to induce inappropriate survival pathways. All together, our results are consistent with a role of SRF at the interface between cell survival and death pathways.

Cleavage and relocation of the tyrosine kinase P59FYN during Fas-mediated apoptosis in T lymphocytes

Ligation of Fas with its natural ligand or with anti-Fas antibodies induces an apoptotic program in Fas sensitive cells. We report here the identification of the tyrosine kinase p59Fyn as a substrate for CPP32-like proteinases and more particularly caspase 3 during Fas-mediated apoptosis in Jurkat T cells. Inhibition of CPP32-like proteinases by Ac-Asp-Glu-Val-Asp-aldehyde but not by Ac-Tyr-Val-Ala-Asp-aldehyde prevents CPP32, PARP and p59Fyn cleavage indicating that CPP32 or CPP32-like proteinases are responsible for the cleavage of p59Fyn. Cleavage occurs in the N-terminal domain of p59Fyn between Asp19 and Gly20 and is accompanied by relocation of an active p57Fyn kinase to cytoplasm of Fas-stimulated Jurkat cells as judged by both biochemical and confocal microscopy experiments. Thus, p59Fyn relocation and activity may play an important role during Fas-mediated cell death in human T lymphocytes.