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Qualitative and quantitative CT imaging features might intercept the multifaceted tumor immune microenvironment (TIME), providing a non-invasive approach to design new prognostic models in NSCLC patients.Our study population consisted of 100 surgically resected NSCLC patients among which 31 served as a validation cohort for quantitative image analysis. TIME was classified according to PD-L1 expression and the magnitude of Tumor Infiltrating Lymphocytes (TILs) and further defined as hot or cold by the tissue analysis of effector (CD8-to-CD3Specific CT-SFs (texture [TXT], effect [EFC] and margins [MRG]) strongly correlated to PD-L1 and TILs status and showed significant impact on survival outcome (TXT, HR:3.39, 95 % CI 1.12-10-27, P 0.05; EFC, HR:0.41, 95 % CI 0.18-0.93, P 0.05; MRG, HR:1.93, 95 % CI 0.88-4.25, P = 0.09). Seven CT derived radiomic features were able to sharply discriminate cases with hot (inflamed) vs cold (desert) TIME, which also exhibited opposite OS (long vs short, HR:0.09, 95 % CI 0.04-0.23, P 0.001) and DFS (long vs short, HR:0.31, 95 % CI 0.16-0.58, P 0.001). Moreover, we identified 6 prognostic radiomic features among which ClusterProminence displayed the highest statistical significance (HR:0.13, 95 % CI 0.06-0.31, P 0.001). These findings were independently validated in an additional cohort of NSCLC (HR:0.11, 95 % CI 0.03-0.40, P = 0.001). Finally, in our training cohort we developed a multiparametric prognostic model, interlacing TIME and clinico-pathological characteristics with CT-SFs (ROC curve AUC:0.83, 95 % CI 0.71-0.92, P 0.001) or CT-RFs (AUC: 0.91, 95 % CI 0.83-0.99, P 0.001), which appeared to outperform pTNM staging (AUC: 0.66, 95 % CI 0.51-0.80, P 0.05) in the risk assessment of NSCLC.Higher order CT extracted features associated with specific TIME profiles may reveal a radio-immune signature with prognostic impact on resected NSCLC.

Background Non-communicable diseases, intended as the results of a combination of inherited, environmental and biological factors, kill 40 million people each year, equivalent to roughly 70% of all premature deaths globally. The possibility that manufactured nanoparticles (NPs) may affect cardiac performance, has led to recognize NPs-exposure not only as a major Public Health concern, but also as an occupational hazard. In volunteers, NPs-exposure is problematic to quantify. We recently found that inhaled titanium dioxide NPs, one of the most produced engineered nanomaterials, acutely increased cardiac excitability and promoted arrhythmogenesis in normotensive rats by a direct interaction with cardiac cells. We hypothesized that such scenario can be exacerbated by latent cardiovascular disorders such as hypertension. Results We monitored cardiac electromechanical performance in spontaneously hypertensive rats (SHRs) exposed to titanium dioxide NPs for 6 weeks using a combination of cardiac functional measurements associated with toxicological, immunological, physical and genetic assays. Longitudinal radio-telemetry ECG recordings and multiple-lead epicardial potential mapping revealed that atrial activation times significantly increased as well as proneness to arrhythmia. At the third week of nanoparticles administration, the lung and cardiac tissue encountered a maladaptive irreversible structural remodelling starting with increased pro-inflammatory cytokines levels and lipid peroxidation, resulting in upregulation of the main pro-fibrotic cardiac genes. At the end of the exposure, the majority of spontaneous arrhythmic events terminated, while cardiac hemodynamic deteriorated and a significant accumulation of fibrotic tissue occurred as compared to control untreated SHRs. Titanium dioxide nanoparticles were quantified in the heart tissue although without definite accumulation as revealed by particle-induced X-ray emission and ultrastructural analysis. Conclusions The co-morbidity of hypertension and inhaled nanoparticles induces irreversible hemodynamic impairment associated with cardiac structural damage potentially leading to heart failure. The time-dependence of exposure indicates a non-return point that needs to be taken into account in hypertensive subjects daily exposed to nanoparticles. Electronic supplementary material The online version of this article (10.1186/s12989-019-0311-7) contains supplementary material, which is available to authorized users.

Background: Malignant Pleural Mesothelioma (MPM) is an aggressive tumor that has a significant incidence related to asbestos exposure with no effective therapy and poor prognosis. The role of mesenchymal stromal cells (MSCs) in cancer is controversial due to their opposite effects on tumor growth and in particular, only a few data are reported on MSCs and MPM. Methods: We investigated the in vitro efficacy of adipose tissue-derived MSCs, their lysates and secretome against different MPM cell lines. After large-scale production of MSCs in a bioreactor, their efficacy was also evaluated on a human MPM xenograft in mice. Results: MSCs, their lysate and secretome inhibited MPM cell proliferation in vitro with S or G0/G1 arrest of the cell cycle, respectively. MSC lysate induced cell death by apoptosis. The efficacy of MSC was confirmed in vivo by a significant inhibition of tumor growth, similar to that produced by systemic administration of paclitaxel. Interestingly, no tumor progression was observed after the last MSC treatment, while tumors started to grow again after stopping chemotherapeutic treatment. Conclusions: These data demonstrated for the first time that MSCs, both through paracrine and cell-to-cell interaction mechanisms, induced a significant inhibition of human mesothelioma growth. Since the prognosis for MPM patients is poor and the options of care are limited to chemotherapy, MSCs could provide a potential new therapeutic approach for this malignancy.

Radiomics has emerged as a noninvasive tool endowed with the potential to intercept tumor characteristics thereby predicting clinical outcome. In a recent study on resected non-small cell lung cancer (NSCLC), we identified highly prognostic computed tomography (CT) -derived radiomic features (RFs), which in turn were able to discriminate hot from cold tumor immune microenvironment (TIME). We aimed at validating a radiomic model capable of dissecting specific TIME profiles bearing prognostic power in resected NSCLC. The validation cohort included 31 radically resected NSCLCs clinicopathologically matched with the training set (n = 69). TIME was classified in hot and cold according to a multiparametric immunohistochemical analysis involving PD-L1 score and incidence of immune effector phenotypes among tumor infiltrating lymphocytes (TILs). High- throughput radiomic features (n = 841) extracted from CT images were correlated to TIME parameters to ultimately define prognostic classes. We confirmed PD-1 to CD8 ratio as best predictor of clinical outcome among TIME characteristics. Significantly prolonged overall survival (OS) was observed in patients carrying hot (median OS not reached) vs cold (median OS 22 months; hazard ratio 0.28, 95% confidence interval 0.09 -0.82; p = 0.015) immune background, thus validating the prognostic impact of these two TIME categories in resected NSCLC. Importantly, in the validation setting, three out of eight previously identified RFs sharply distinguishing hot from cold TIME were endorsed. Among signature-related RFs, Wavelet-HHH_gldm_HighGrayLevelEmphasis highly performed as descriptor of hot immune contexture (area under the receiver operating characteristic curve 0.94, 95% confidence interval 0.81 -1.00; p = 0.01). Based on our findings, Radiomics may decipher specific TIME profiles providing a noninvasive prognostic approach in resected NSCLC and an exploitable predictive strategy in advanced cases.

Background: Evaluation of fibrosis and its severity is the commonest parameter to screen potential new medicines in rodents treated with bleomycin (BLM). Results are mainly reported by histological analysis and indirect measurement of collagen through hydroxyproline (HYP) quantification. Objectives: In the present study we performed a comparative analysis of different methods to assess collagens induced by BLM in the mouse lung. Methods: BLM (0.02 U/kg) was administered by oropharyngeal aspiration to male C57BL/6 mice on day 0 and day 4. Oral Nintedanib (60 mg/kg/day) started from day 7. Three and four weeks after the first BLM administration, histopathological examination and collagen genes expression analysis were applied. Moreover, HYP and collagen isoforms (LC-MS) quantification in lung homogenates were assessed. Results: Ashcroft score and automated measure of lung fibrosis revealed significant fibrotic lesions in BLM-treated animals. Specific collagen genes appeared up-regulated in BLM group. LC-MS quantification of collagen isoforms correlated with HYP levels although, interestingly, showed a higher therapeutic window between control and BLM group (1.5 vs. 0.5 fold, respectively). Nintedanib significantly affected all the evaluated readouts. Conclusions: Our study provides a comprehensive analysis of changes in collagen genes and proteins following BLM treatment in mice and the effect of Nintedanib. Importantly, our data indicate for the first time LC-MS as a sensitive and reliable method for collagen quantification in lung homogenate. This approach might implement the most employed HYP assay to achieve reliable predictions of efficacy for therapeutics in lung fibrosis.

The immune regulation of cancer growth and regression has been underscored by the recent success of immunotherapy. The possibility that immune microenvironmental factors may impact on clinical outcome and treatment response still requires intense investigations. Hereby, supporting data of the research article “Integrated CT Imaging and Tissue Immune Features Disclose a Radio-Immune Signature with High Prognostic Impact on Surgically Resected NSCLC” [1], are presented. With the ultimate aim to provide non-invasive prognostic scores, we report on our approach to correlate different Tumor Immune Microenvironment (TIME) profiles with CT imaging-derived qualitative (semantic, CT-SFs) and quantitative (radiomic, CT-RFs) features in a cohort of 60 surgically resected NSCLC. The renowned characterization of TIME, essentially based on the score evaluation of Programme Death Ligand-1 (PD-L1) and Tumor Infiltrating Lymphocytes (TILs), was implemented here by the assessment of effector and suppressor phenotypes including the analysis of Programme Death receptor 1 (PD-1). Thus, we defined two main TIME categories: hot inflamed (PD-L1high, CD8/CD3high and PD-1/CD8low) as opposed to cold inactive (PD-L1low, CD8/CD3lowand PD-1/CD8high). Importantly, as reported in the extended publication [1], these distinctive immune contextures identified different prognostic classes and were decoded by radiomics. To corroborate our radiomic approach, a comparative estimation of CT-RFs extracted from 60 NSCLC and 13 non neoplastic tissues was undertaken, documenting high discrimination ability. Moreover, we tested the potential association of qualitative radiologic features with clinico-pathological and TIME parameters. Taken together, our findings suggest that CT-SFs and CT-RFs may underlay specific patterns of lung cancer.

Stem cell-based therapeutics is a rapidly developing field associated with a number of clinical challenges. One such challenge lies in the implementation of methods to track stem cells and stem cell-derived cells in experimental animal models and in the living patient. Here, we provide an overview of cell tracking in the context of cardiac and neurological disease, focusing on the use of iron oxide-based particles (IOPs) visualized in vivo using magnetic resonance imaging (MRI). We discuss the types of IOPs available for such tracking, their advantages and limitations, approaches for labeling cells with IOPs, biological interactions and effects of IOPs at the molecular and cellular levels, and MRI- based and associated approaches for in vivo and histological visualization. We conclude with reviews of the literature on IOP-based cell tracking in cardiac and neurological disease, covering both preclinical and clinical studies.

c-Kitpos cardiac progenitor cells (CPCs) represent a successful approach in healing the infarcted heart and rescuing its mechanical function, but electrophysiological consequences are uncertain. CPC mobilization promoted by hepatocyte growth factor (HGF) and IGF-1 improved electrogenesis in myocardial infarction (MI). We hypothesized that locally delivered CPCs supplemented with HGF + IGF-1 (GFs) can concur in ameliorating electrical stability of the regenerated heart. Adult male Wistar rats (139 rats) with 4-wk-old MI or sham conditions were randomized to receive intramyocardial injection of GFs, CPCs, CPCs + GFs, or vehicle (V). Enhanced green fluorescent protein-tagged CPCs were used for cell tracking. Vulnerability to stress-induced arrhythmia was assessed by telemetry-ECG. Basic cardiac electrophysiological properties were examined by epicardial multiple-lead recording. Hemodynamic function was measured invasively. Hearts were subjected to anatomical, morphometric, immunohistochemical, and molecular biology analyses. Compared with V and at variance with individual CPCs, CPCs + GFs approximately halved arrhythmias in all animals, restoring cardiac anisotropy toward sham values. GFs alone reduced arrhythmias by less than CPCs + GFs, prolonging ventricular refractoriness without affecting conduction velocity. Concomitantly, CPCs + GFs reactivated the expression levels of Connexin-43 and Connexin-40 as well as channel proteins of key depolarizing and repolarizing ion currents differently than sole GFs. Mechanical function and anatomical remodeling were equally improved by all regenerative treatments, thus exhibiting a divergent behavior relative to electrical aspects. Conclusively, we provided evidence of distinctive antiarrhythmic action of locally injected GF-supplemented CPCs, likely attributable to retrieval of Connexin-43, Connexin-40, and Cav1.2 expression, favoring intercellular coupling and spread of excitation in mended heart.

Background & Objectives: The aim of this study was to investigate the time-course of the molecular and histological changes induced by a double intratracheal (IT) administration of bleomycin (BLM) on lung tissue. Methods: Male SD rats were injected with BLM (2 U/kg, IT) or saline on day 0 and day 4 and sacrificed at day 7, 14, 21, 28 and 56 after BLM first dose. Several inflammatory and fibrotic biomarkers were assessed in lung, BALF and plasma by colorimetric or immunometric assays. Histomorphometric analysis of lung fibrosis was performed on Masson’s trichrome stained sections. Results & Conclusions: In lungs of BLM-treated animals, several ECM proteins were significantly increased at day 7 (30-, 40- and 80-fold increase for TIMP1, PAI-1 and SPP1, respectively), and progressively declined over time, reaching control values at day 56. A significant increase in lung hydroxyproline levels was evident starting from day 14 (2.4-fold increase) and was maintained over the duration of the study. Histomorphometric evaluation revealed a sustained fibrosis during the first three weeks (fibrotic area: 50%), followed by a progressive reduction at day 28 and 56 (30%). Overall, these results indicate that the most suitable time point for assessing lung fibrosis and its targeted interventions is between 21 and 28 days post-BLM, where the fibrotic response appears to be more stable and consistent. Additional investigations, including transcriptomic and proteomic approaches will be essential to obtain a more comprehensive characterisation of the present model.

OBJECTIVES: Lymphangiogenesis plays a critical role in the immune response, tumour progression and therapy effectiveness. The aim of this study was to determine whether the interplay between the lymphatic and the blood microvasculature, tumour-infiltrating lymphocytes and the programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) immune checkpoint constitutes an immune microenvironment affecting the clinical outcome of patients with non-small-cell lung cancer. METHODS: Samples from 50 squamous cell carcinomas and 42 adenocarcinomas were subjected to immunofluorescence to detect blood and lymphatic vessels. CD3pos, CD8pos and PD-1pos tumour-infiltrating lymphocytes and tumour PD-L1 expression were assessed by immunohistochemical analysis. RESULTS: Quantification of vascular structures documented a peak of lymphatics at the invasive margin together with a decreasing gradient of blood and lymphatic vessels from the peritumour area throughout the neoplastic core. Nodal involvement and pathological stage were strongly associated with vascularization, and an increased density of vessels was detected in samples with a higher incidence of tumour-infiltrating lymphocytes and a lower expression of PD-L1. Patients with a high PD-L1 to PD-1 ratio and vascular rarefaction had a gain of 10 months in overall survival compared to those with a low ratio and prominent vascularity. CONCLUSIONS: Microvessels are an essential component of the cancer immune microenvironment. The clinical impact of the PD-1/PD-L1-based immune contexture may be implemented by the assessment of microvascular density to potentially identify patients with non-small-cell lung cancer who could benefit from immunotherapy and antiangiogenic treatment.

Cardiovascular complications are included among the systemic effects of tyrosine kinase inhibitor (TKI)-based therapeutic strategies. To test the hypothesis that inhibition of Kit tyrosine kinase that promotes cardiac progenitor cell (CPC) survival and function may be one of the triggering mechanisms of imatinib mesylate (IM)-related cardiovascular effects, the anatomical, structural and ultrastructural changes in the heart of IM-treated rats were evaluated. Cardiac anatomy in IM-exposed rats showed a dose-dependent, restrictive type of remodeling and depressed hemodynamic performance in the absence of remarkable myocardial fibrosis. The effects of IM on rat and human CPCs were also assessed. IM induced rat CPC depletion, reduced growth and increased cell death. Similar effects were observed in CPCs isolated from human hearts. These results extend the notion that cardiovascular side effects are driven by multiple actions of IM. The identification of cellular mechanisms responsible for cardiovascular complications due to TKIs will enable future strategies aimed at preserving concomitantly cardiac integrity and anti-tumor activity of advanced cancer treatment.

Background The identification of ALK and ROS1 rearrangements and the availability of an effective target therapy, such as crizotinib, represent a new option in the treatment of advanced non-small cell lung cancer (NSCLC) patients. In light of recent advances in non-invasive diagnostic procedures, we aimed to demonstrate that direct cytological smears are suitable for assessing ALK and ROS1 rearrangements in patients with NSCLC. Methods Fifty-five patients with a cytological diagnosis of lung adenocarcinoma (ADC) were evaluated for ALK rearrangements by fluorescence in situ hybridization (FISH) and 12 patients for ROS1 FISH rearrangements. Seventeen of the 55 cytological samples tested for ALK were obtained from the primary tumor and 38 from metastatic lesions. Ten of 12 samples evaluated for ROS1 were obtained from metastatic sites and two from the primary tumor. Results ALK FISH was successful in 49/55 (89%) cytological ADC samples and ROS1 FISH in all 12 cytological samples. ALK rearrangements were found in 3/13 (23%) primary tumors and 7/36 (19%) metastatic sites. ROS1 rearrangements were found in one of the two primary tumors and in two of the 10 metastases. Two of the three rearranged cases were tested on cytology after knowing that they were rearranged on histology in order to increase representativeness of ROS1 rearranged cases in this study. Conclusion Whenever cytology represents the only available material for diagnosis and biological characterization of NSCLC, minimally invasive procedures may provide an additional important source of cellular material for FISH assessment of ALK and ROS1 rearrangements.//// Diagn. Cytopathol. 2015;43:941–946. © 2015 Wiley Periodicals, Inc.

One of the main cause of ineffective cell therapy in repairing the damaged heart is the poor yield of grafted cells. To overcome this drawback, rats with 4-week-old myocardial infarction (MI) were injected in the border zone with human adipose-derived stem cells (ADSCs) conveyed by poly(lactic-co-glycolic acid) microcarriers (PAMs) releasing hepatocyte growth factor (HGF) and insulin-like growth factor-1 (IGF-1) (GFsPAMs). According to treatments, animals were subdivided into different groups: MI_ADSC, MI_ADSC/PAM, MI_GFsPAM, MI_ADSC/GFsPAM, and untreated MI_V. Two weeks after injection, a 31% increase in ADSC engraftment was observed in MI_ADSC/PAM compared with MI_ADSC (p

Background: Idiopathic Pulmonary Fibrosis (IPF), is a progressive lung disease characterized by basal and subpleural fibrosis associated with honeycomb changes. In experimental settings, single intratracheal (IT) administration of bleomycin (BLM) to rodents is the most commonly used model. In order to more closely mimic human IPF, a novel experimental procedure with two IT administrations of BLM in rats is described. Aims and objectives: Histological and biomolecular findings following single and double IT administration of BLM in the rat were compared. Furthermore, the effect of Nintedanib was assessed. Methods: Single (4U/Kg, day 1) or double (2 X 2U/Kg, day 1 and day 4) administration of BLM was given IT to male SD rats. Nintedanib (100 mg/kg, oral) was administered once daily for three weeks starting from day 7. Morphometric quantification of different patterns of lung fibrosis and cluster gene expression on tissue homogenate (Real Time PCR) were performed. Results: A single BLM administration induced focal collagen deposition mostly surrounding the main bronchi. In contrast, two BLM administrations seemed to evoke a more diffuse pattern of interstitial collagen deposition widening lung parenchyma. Reduction of lung fibrosis by Nintedanib was more effective in the 2 X 2U/Kg group (~46%) compared to 4U/Kg group (~11%). Moreover, normalisation by Nintedanib of differentially modulated IPF-associated genes was more evident in 2 X 2U/Kg group. Conclusions: Our study provides a novel improved BLM rat model of IPF that is sensitive to the effect of Nintedanib and functional to assess efficacy in drug development.

OBJECTIVES: The aim of the present study was to characterize the biological properties and in vivo tumourigenic potential of mesenchymal cells (MCs) obtained from non-small-cell lung cancer (NSCLC) samples. METHODS: NSCLC samples (53 adenocarcinomas and 24 squamous-cell carcinomas) surgically removed from 46 males and 31 females were processed to identify mesenchymal cells from human lung cancer (hLc-MCs). hLc-MCs were separated from neoplastic epithelial cells, expanded and extensively characterized in vitro. Subsequently, female BALB/c nude mice were subcutaneously injected with either 10 6 or 2.5 × 10 6 Calu-3 (human adenocarcinoma cell line able to reproducibly induce xenografted tumours) alone or in combination with equal doses of hLc-MCs. Control animals were injected with the two doses of hLc-MCs only. RESULTS: Primary cultures of hLc-MCs were obtained from >80% of NSCLC specimens. The typical MCs immunophenotype was documented by the expression of CD90, CD105, CD73, CD13 and CD44 at fluorescence-activated cell sorting analysis. CD45, CD14, CD34 and epithelial antigens were negative while CD117 (c-kit) and CD133 (prominin) were partially expressed. Interestingly, nuclear transcription factors octamer-binding transcription factor 3/4 and sex determining region Y-box 2 involved in stemness, thyroid transcription factor 1 in bronchoalveolar commitment, and ETS1 in carcinogenesis, were expressed in hLc-MCs isolated from NSCLC. Specific conditioned media and cocultures confirmed the supportive role of hLc-MCs for cancer cells. In vivo experiments showed that at both doses Calu-3 xenografts doubled in size when hLc-MCs were coinjected. Cell tracking in xenografted tumours, by immunofluorescence combined with fluorescence in situ hybridization analysis, documented hX-chromosome-labelled, Calu-3-derived cytokeratin-positive adenocarcinoma structures surrounded by hLc-MCs. CONCLUSIONS: Tumour-propagating cells require the inductive interaction of resident mesenchymal cells to foster lung cancer development.

Emerging evidence suggests that both adult cardiac cell and the cardiac stem/progenitor cell (CSPC) compartments are involved in the patho-physiology of diabetic cardiomyopathy (DCM). We evaluated whether early administration of Resveratrol, a natural antioxidant polyphenolic compound, in addition to improving cardiomyocyte function, exerts a protective role on (i) the progenitor cell pool, and (ii) the myocardial environment and its impact on CSPCs, positively interfering with the onset of DCM phenotype. Adult Wistar rats (n = 128) with streptozotocin-induced type-1 diabetes were either untreated (D group; n = 54) or subjected to administration of trans-Resveratrol (i.p. injection: 2.5 mg/Kg/day; DR group; n = 64). Twenty-five rats constituted the control group (C). After 1, 3 or 8 weeks of hyperglycemia, we evaluated cardiac hemodynamic performance, and cardiomyocyte contractile properties and intracellular calcium dynamics. Myocardial remodeling and tissue inflammation were also assessed by morphometry, immunohistochemistry and immunoblotting. Eventually, the impact of the diabetic "milieu" on CSPC turnover was analyzed in co-cultures of healthy CSPCs and cardiomyocytes isolated from D and DR diabetic hearts. In untreated animals, cardiac function was maintained during the first 3 weeks of hyperglycemia, although a definite ventricular remodeling was already present, mainly characterized by a marked loss of CSPCs and adult cardiac cells. Relevant signs of ventricular dysfunction appeared after 8 weeks of diabetes, and included: 1) a significant reduction in ±dP/dt in comparison with C group, 2) a prolongation of isovolumic contraction/relaxation times, 3) an impaired contraction of isolated cardiomyocytes associated with altered intracellular calcium dynamics. Resveratrol administration reduced atrial CSPC loss, succeeded in preserving the functional abilities of CSPCs and mature cardiac cells, improved cardiac environment by reducing inflammatory state and decreased unfavorable ventricular remodeling of the diabetic heart, leading to a marked recovery of ventricular function. These findings indicate that RSV can constitute an adjuvant therapeutic option in DCM prevention.

Recent literature has identified innovative approaches of cellular therapy to generate new myocardium involving transcoronary and intramyocardial injection of cardiac progenitor cells (CPCs). One of the limiting factors in the overall interpretation of these preclinical results is the lack of reliable methods for 3D imaging and quantification of the injected cells and for the assessment of their fate within the myocardium. Here, for the first time to the authors' knowledge, we support by demonstrative experiments the hypothesis that phase-contrast microtomography (PhC-microCT) could offer an efficient 3D imaging approach to track the injected cells within the myocardium, without the need of any cell tracer. This deduction has been validated by several observations: i) a strong phase-contrast signal was observed in infarcted hearts injected with unlabeled cells; ii) the PhC-microCT 3D reconstructions of hearts injected with only vehicle saline solution and rhodamine particles, i.e. without CPCs, did not show any contrast; (iii) in the 3D PhC-microCT reconstructions of non infarcted hearts, injected with unlabeled CPCs, the contrast signal of the cells was present but differently distributed; and iv) the contrast signal of injected cells diminished over time apparently following the same timing of cell engraftment and differentiation, as confirmed in literature by histology and fluorescence analysis. The chance to avoid cell tracers is of paramount interest in determining the fate of transplanted stem cells because the quantification of the signal will not be any more dependent on injected dose, concentration of the tracer, cell proliferation and tracer uptake kinetics.

Background The search for compounds able to counteract chemotherapy-induced heart failure is extremely important at the age of global cancer epidemic. The role of SIRT1 in the maintenance of progenitor cell homeostasis may contribute to its cardioprotective effects. SIRT1 activators, by preserving progenitor cells, could have a clinical relevance for the prevention of doxorubicin (DOXO)-cardiotoxicity. Methods To determine whether SIRT1 activator, resveratrol (RES), interferes with adverse effects of DOXO on cardiac progenitor cells (CPCs): 1) human CPCs (hCPCs) were exposed in vitro to DOXO or DOXO+RES and their regenerative potential was tested in vivo in an animal model of DOXO-induced heart failure; 2) the in vivo effects of DOXO+RES co-treatment on CPCs were studied in a rat model. Results In contrast to healthy cells, DOXO-exposed hCPCs were ineffective in a model of anthracycline cardiomyopathy. The in vitro activation of SIRT1 decreased p53 acetylation, overcame suppression of the IGF-1/Akt pro-survival and anti-apoptotic signaling, enhanced oxidative stress defense and prevented senescence and growth arrest of hCPCs. Priming with RES counterbalanced the onset of dysfunctional phenotype in DOXO-exposed hCPCs, partly restoring their ability to repair the damage with improvement in cardiac function and animal survival. The in vivo co-treatment DOXO+RES prevented the anthracycline-induced alterations in CPCs, partly preserving cardiac function. Conclusion SIRT1 activation protects DOXO-exposed CPCs and re-establishes their proper function. Pharmacological intervention at the level of tissue-specific progenitor cells may provide cardiac benefits for the growing population of long-term cancer survivors that are at risk of chemotherapy-induced cardiovascular toxicity.

We tested the hypothesis that cardiac regeneration through local delivery of adipose-derived stem cells (ASCs), activation of resident cardiac stem cells via growth factors (GFs) [hepatocyte growth factor (HGF) and insulin-like growth factor 1 (IGF-1):GFs] or both, are improved by pharmacologically active microcarriers (PAMs) interacting with cells/molecules conveyed on their surface. Rats with one-month old myocardial infarction were treated with ASCs, ASCs+PAMs, GF-releasing PAMs, ASCs+GF-releasing PAMs or vehicle. Two weeks later, hemodynamic function and inducibility of ventricular arrhythmias (VAs) were assessed. Eventually, the hearts were subjected to anatomical and immunohistochemical analyses. A significant ASCs engraftment and the largest improvement in cardiac mechanics occurred in ASC+GF-releasing PAM rats which by contrast were more vulnerable to VAs. Thus, PAMs may improve cell/GF-based cardiac regeneration although caution should be paid on the electrophysiological impact of their physical interaction with the myocardium.

Aims Bone marrow mesenchymal stromal cell (BMStC) transplantation into the infarcted heart improves left ventricular function and cardiac remodelling. However, it has been suggested that tissue-specific cells may be better for cardiac repair than cells from other sources. The objective of the present work has been the comparison of in vitro and in vivo properties of adult human cardiac stromal cells (CStC) to those of syngeneic BMStC. Methods and results Although CStC and BMStC exhibited a similar immunophenotype, their gene, microRNA, and protein expression profiles were remarkably different. Biologically, CStC, compared with BMStC, were less competent in acquiring the adipogenic and osteogenic phenotype but more efficiently expressed cardiovascular markers. When injected into the heart, in rat a model of chronic myocardial infarction, CStC persisted longer within the tissue, migrated into the scar, and differentiated into adult cardiomyocytes better than BMStC. Conclusion Our findings demonstrate that although CStC and BMStC share a common stromal phenotype, CStC present cardiovascular-associated features and may represent an important cell source for more efficient cardiac repair.

Cardiovascular diseases and cancer represent respectively the first and second cause of death in industrialized countries. These two conditions may become synergistic when cardiovascular complications of anti-cancer therapy are considered. More than 70% of childhood and 50% of adult cancer patients can be cured, however this important success obtained by the biological and medical research is obfuscated by emerging findings of early and late morbidity due to cardiovascular events. Although anthracyclines are effective drugs against cancer a dose-dependent cardiotoxic effects whose mechanism has not been elucidated resulting in failure of therapeutic interventions limit their use. Unexpectedly, tyrosine/ kinase inhibitors (TKIs) aimed at molecularly interfering with oncogenic pathways, have been implicated in cardiac side effects. Possible explanations of this phenomenon have been ambiguous, further strengthening the need to deepen our understanding on the mechanism of cardiotoxicity. In addition to a detailed description of anthracyclines and TKIs-related cardiovascular effects, the present review highlights recent observations supporting the hypothesis that the cellular target of anthracyclines and TKIs may include myocardial compartments other than parenchymal cells. The demonstration that the adult mammalian heart possesses a cell turnover regulated by primitive cells suggests that this cell population may be implicated in the onset and development of cardiovascular effects of anti-cancer strategies. The possibility of preventing cardiotoxicity by preservation and/or expansion of the resident stem cell pool responsible for cardiac repair may open new therapeutic options to unravel an unsolved clinical issue.

Heart repair by stem cell treatment may involve life-threatening arrhythmias. Cardiac progenitor cells (CPCs) appear best suited for reconstituting lost myocardium without posing arrhythmic risks, being commissioned towards cardiac phenotype. In this study we tested the hypothesis that mobilization of CPCs through locally delivered Hepatocyte Growth Factor and Insulin-Like Growth Factor-1 to heal chronic myocardial infarction (MI), lowers the proneness to arrhythmias. We used 133 adult male Wistar rats either with one-month old MI and treated with growth factors (GFs, n = 60) or vehicle (V, n = 55), or sham operated (n = 18). In selected groups of animals, prior to and two weeks after GF/V delivery, we evaluated stress-induced ventricular arrhythmias by telemetry-ECG, cardiac mechanics by echocardiography, and ventricular excitability, conduction velocity and refractoriness by epicardial multiple-lead recording. Invasive hemodynamic measurements were performed before sacrifice and eventually the hearts were subjected to anatomical, morphometric, immunohistochemical, and molecular biology analyses. When compared with untreated MI, GFs decreased stress-induced arrhythmias and concurrently prolonged the effective refractory period (ERP) without affecting neither the duration of ventricular repolarization, as suggested by measurements of QTc interval and mRNA levels for K-channel α-subunits Kv4.2 and Kv4.3, nor the dispersion of refractoriness. Further, markers of cardiomyocyte reactive hypertrophy, including mRNA levels for K-channel α-subunit Kv1.4 and β-subunit KChIP2, interstitial fibrosis and negative structural remodeling were significantly reduced in peri-infarcted/remote ventricular myocardium. Finally, analyses of BrdU incorporation and distribution of connexin43 and N-cadherin indicated that cytokines generated new vessels and electromechanically-connected myocytes and abolished the correlation of infarct size with deterioration of mechanical function. In conclusion, local injection of GFs ameliorates electromechanical competence in chronic MI. Reduced arrhythmogenesis is attributable to prolongation of ERP resulting from improved intercellular coupling via increased expression of connexin43, and attenuation of unfavorable remodeling.

Abstract 2200 Poster Board II-177 Cardiotoxicity is a limiting factor of successful anthracycline-based anticancer regimens. Recently, cardiac side effects have been also reported for Tyrosine Kinase Inhibitors, among which Imatinib Mesylate (IM) has been able to change the natural history of Chronic Myeloid Leukemia (CML) and Gastrointestinal Stromal Tumors. The mechanism of IM-related cardiac dysfunction has not been fully elucidated. Since we have demonstrated the presence of resident cardiac stem cells controlling homeostasis of the human and murine heart, we advanced the hypothesis that IM-induced cardiotoxicity involves myocardial cell turnover resulting in an impairment of the adaptive response of the heart to the toxic insult. To this purpose, we studied the in vitro genotoxic effect of 5mM, 25mM and 50 mM concentrations of IM on human and rat Cardiac Progenitor Cells (CPCs). Freshly isolated human BM CML cells carrying Bcr/Abl translocation served as control. In addition, to ascertain whether IM affects cardiac structure and function, young rats were treated by three weekly i.p. injections of 50, 100 and 200 mg/kg IM for 4 weeks when hemodynamic parameters and LV remodelling were analyzed. A dose and time dependent DNA damage was observed in both CPCs and CML after in vitro exposure to IM. As early as 6 hours after 50 mM IM, DNA double strand breaks formation (dSBs), as shown by immunostaining of Histone A2X, involved 50% and 70% of CPCs and CML, respectively. At later time points more than 80% of both cells died. However, low concentrations (5mM), corresponding to therapeutic doses, exerted a permissive reparative response on CPCs that persisted with time. As a result of this divergent effect, CPCs proliferation and survival increased from 12 to 24 h in spite of the presence of IM. In vivo studies showed that, following 200 mg/kg IM, all animals died within the first 2 weeks. In the presence of moderate anemia, diastolic dysfunction was present even at 50 mg/kg IM and a dose dependent impairment in Left Ventricular End Diastolic Pressure (LVEDP) and +/- dP/dT was observed. Anatomical parameters indicated that only higher doses IM resulted in a smaller LV with a concentric type of remodelling. In the absence of diffuse myocardial fibrosis and/or high levels of apoptosis, small foci of myocardial damage were observed only with 200 mg/kg IM. Preliminary data on myocardial cell turnover indicate that high doses of IM blunted the proliferative response.of cardiomyocytes to the cytotoxic injury. Conversely, in agreement with in vitro data, low IM doses were associated with a reparative response. In conclusion, IM, by inhibiting the multiple pathways modulated by tyrosine kinases, affects in a dose dependent manner CPCs and cardiac function suggesting possible alternative mechanisms of its effects on the cardiovascular system. Disclosures: No relevant conflicts of interest to declare.

Abstract 1482 Poster Board I-505 Alterations in cell trafficking and chemoattractive properties may represent basic mechanisms responsible for organ pathology in diabetes mellitus (DM). These functional events involving both inflammatory and progenitor cells may be translated in the proneness to major septic events and effaced reparative response characterizing the clinical course of the disease. To determine whether DM affects BM progenitor cell number and function, tissue resident and GSF mobilized disease-free BM CD34pos cells were evaluated in 19 DM and 38 non-diabetic control (CTR) biopsies and in 18 DM and 48 CTR patients undergoing autologous BM transplantation. DM was documented by the presence of glucose intolerance, HbA1C > 6 g% and need of high dose insulin treatment. CTR were selected on the basis of normal glucose tolerance and the absence of neoplastic infiltration and/or morphologic changes in cellular hematopoietic compartments compatible with hematologic disorders. Reduction in trabecular bone, fat accumulation, rearrangement of microvascular structures and marked DNA oxidative damage characterized BM structural and cellular remodelling in DM. Immunohistochemical and FACS analysis documented that DM produced a 50% reduction in the number of both BM resident and mobilized CD34pos Linneg cells. In addition only 16% of diabetic patients were able to mobilize >10 × 106 CD34pos cells/kg compared to 62% of CTR. After infusion of mobilized CD34pos progenitors, BM engraftment was partially prolonged in diabetic patients. Severe impairment of SC engraftment by DM was striking by the comparative analysis of the infusion of similar number of mononuclear cells (nearly 180 ×106/Kg) directly harvested from the bone marrow of DM and CTR patients. In this setting, PMN and Plts recovery was delayed by nearly 2 and 4 weeks, respectively. Thus, DM severely affects human progenitor cell function and BM microenvronment in vivo inevitably impairing the outcome of BM transplantation. Whether all these changes are due to specific perturbation of the GSF-dependent SDF-1/CXCR4 axis and whether drugs interfering with ROS mediated damage may reverse this phenomenon is under intense investigation. Disclosures: No relevant conflicts of interest to declare.

The introduction of stem cells in cardiology provides new tools in understanding the regenerative processes of the normal and pathologic heart and opens new options for the treatment of cardiovascular diseases. The feasibility of adult bone marrow autologous and allogenic cell therapy of ischemic cardiomyopathies has been demonstrated in humans. However, many unresolved questions remain to link experimental with clinical observations. The demonstration that the heart is a self-renewing organ and that its cell turnover is regulated by myocardial progenitor cells offers novel pathogenetic mechanisms underlying cardiac diseases and raises the possibility to regenerate the damaged heart. Indeed, cardiac stem progenitor cells (CSPCs) have recently been isolated from the human heart by several laboratories although differences in methodology and phenotypic profile have been described. The present review points to the potential role of CSPCs in the onset and development of congestive heart failure and its reversal by regenerative approaches aimed at the preservation and expansion of the resident pool of progenitors.