Cannabidiol Protects against Doxorubicin-Induced Cardiomyopathy by Modulating Mitochondrial Function and Biogenesis.

Doxorubicin (DOX) is a widely used, potent chemotherapeutic agent; however, its clinical application is limited because of its dose-dependent cardiotoxicity. DOX's cardiotoxicity involves increased oxidative/nitrative stress, impaired mitochondrial function in cardiomyocytes/endothelial cells and cell death. Cannabidiol (CBD) is a nonpsychotropic constituent of marijuana, which is well tolerated in humans, with antioxidant, antiinflammatory and recently discovered antitumor properties. We aimed to explore the effects of CBD in a well-established mouse model of DOX-induced cardiomyopathy. DOX-induced cardiomyopathy was characterized by increased myocardial injury (elevated serum creatine kinase and lactate dehydrogenase levels), myocardial oxidative and nitrative stress (decreased total glutathione content and glutathione peroxidase 1 activity, increased lipid peroxidation, 3-nitrotyrosine formation and expression of inducible nitric oxide synthase mRNA), myocardial cell death (apoptotic and poly[ADP]-ribose polymerase 1 [PARP]-dependent) and cardiac dysfunction (decline in ejection fraction and left ventricular fractional shortening). DOX also impaired myocardial mitochondrial biogenesis (decreased mitochondrial copy number, mRNA expression of peroxisome proliferator-activated receptor γ coactivator 1-alpha, peroxisome proliferator-activated receptor alpha, estrogen-related receptor alpha), reduced mitochondrial function (attenuated complex I and II activities) and decreased myocardial expression of uncoupling protein 2 and 3 and medium-chain acyl-CoA dehydrogenase mRNA. Treatment with CBD markedly improved DOX-induced cardiac dysfunction, oxidative/nitrative stress and cell death. CBD also enhanced the DOX-induced impaired cardiac mitochondrial function and biogenesis. These data suggest that CBD may represent a novel cardioprotective strategy against DOX-induced cardiotoxicity, and the above-described effects on mitochondrial function and biogenesis may contribute to its beneficial properties described in numerous other models of tissue injury.

Cyclooxygenase-2 Expression in Non-Small Cell Lung Cancer Correlates With Hypertrophic Osteoarthropathy.

Hypertrophic osteoarthrpathy (HO) is a rare paraneoplasic syndrome associated with non-small cell lung cancer (NSCLC). The pathophysiology of HO is unknown but was recently related to enhanced levels of urine prostaglandin E2 (PGE2). Here, we report the case of a patient that presented HO in association with a resectable left upper lobe NSCLC. Following surgery and adjuvant chemotherapy, HO resolved and did not recur with development of a brain metastasis 1 year later. Interestingly, tumor cyclooxygenase-2, an enzyme responsible the synthesis of PGE2, was expressed in the primary tumor but not in the resected metastasis.

Etude de l'évolution des patients porteurs d'une cardiomyopathie hypertrophique obstructive (CMHO) après alcoolisation septale

La cardiomyopathie hypertrophique (CMH) est la maladie cardiaque monogénique la plus fréquente, touchant environ 1 individu sur 500 dans la population (1,2). L'étiologie est familiale dans la majorité des cas avec une transmission de type autosomal dominant à pénétrance variable. Deux gènes principaux sont à l'origine de la maladie chez 70% des patients avec un test génétique positif. Il s'agit des gènes qui codent pour la chaine lourde β de la myosine (MYH7) et la protéine C liant la myosine (MYBPC3) (1-3). La CMH est définie par la présence d'une hypertrophie myocardique « inadéquate » car se développant en l'absence d'une cause d'augmentation de la post-charge (HTA, sténose aortique, membrane sous-aortique), d'une pathologie infiltrative ou d'un entrainement physique (4,5). Le plus souvent asymétrique et affectant préférentiellement le septum, cette hypertrophie s'accompagne dans près de deux tiers des cas d'une obstruction dynamique sous-aortique de la chambre de chasse du ventricule gauche par la valve mitrale (systolic anterior motion ou SAM). Cette obstruction est à la fois la conséquence du rétrécissement de la chambre de chasse par l'hypertrophie septale mais également d'un malpositionnement de la valve mitrale (6-8). On parle alors de Cardiomyopathie Hypertrophique et Obstructive (CMHO). L'obstruction - présente au repos dans 50% des cas et uniquement après manoeuvres de provocation dans l'autre moitié des cas (manoeuvre de Valsalva, test de vasodilatation par nitrite d'amyle) est à l'origine d'un gradient de pression entre le ventricule gauche et l'aorte, et donc d'une surcharge de pression pour le ventricule gauche. Cette surcharge de pression est à l'origine des symptômes classiquement rencontrés soit dyspnée et angor d'effort, présyncope voire syncopes à l'effort. Un gradient sous-aortique de plus de 50 mmHg (mesuré au repos ou après provocation) est considéré comme un gradient à valeur pronostique (6-8) et justifiant un traitement si associé à des symptômes. Le traitement médical des formes obstructives repose sur l'administration de substances inotropes négatives et/ou susceptibles de favoriser la relaxation myocardique tels que les béta-bloqueurs, les antagonistes du calcium et le disopyramide - pris isolément ou en association. Pour les nombreux patients qui deviennent réfractaires ou intolérants à ces traitements, deux interventions peuvent leur être proposées pour lever l'obstruction : une myotomie-myectomie chirurgicale du septum (9,10) ou une alcoolisation du septum par voie percutanée (7,8). Les indications à ces interventions sont les suivantes (7,8,11) : 1. Symptômes (dyspnée de classe fonctionnelle NYHA III ou IV, angor de classe fonctionnelle CCS III ou IV, syncope, ou présyncope) réfractaires au traitement médical ou intolérance du patient au traitement. Une dyspnée de classe II est considérée suffisante dans le cas de jeunes patients. 2. Obstruction sous-aortique avec gradient supérieur ou égal à 50 mmHg, au repos ou après manoeuvre de provocation, associée à une hypertrophie septale et à un mouvement systolique antérieur de la valve mitrale (effet SAM) 3. Anatomiecardiaquefavorableàuntraitementinvasif(épaisseurduseptumde plus de 16 mm) Si la myectomie chirurgicale reste la méthode de référence (12-18), l'alcoolisation septale du myocarde par voie percutanée est devenue un des traitements de choix dans la thérapie de la Cardiomyopathie Hypertrophique Obstructive réfractaire. Elle consiste à repérer par coronarographie l'artère septale nourrissant le septum basal hypertrophié, puis à y introduire un petit ballon pour isoler ce territoire du reste du lit coronaire avant d'y injecter une dose d'alcool à 95% comprise entre 1 et 5 cc. On crée ainsi un infarctus chimique, technique qui fut dans le passé utilisée pour le traitement de certaines tumeurs. Les effets ne sont pas immédiats et nécessitent généralement 2-3 semaines avant de se manifester. On assiste alors à une diminution progressive de l'épaisseur du myocarde nécrosé (7), à la disparition progressive de l'obstruction et à l'amélioration / disparition des symptômes. La question de savoir qui de la chirurgie ou de l'alcoolisation est le plus efficace a été source de nombreux débats (7,11-13,18). Par rapport à la chirurgie, les avantages de la méthode percutanée sont les suivants (11,14,15,18,19) : - Efficacités hémodynamique et fonctionnelle jugées comparable à la chirurgie selon les études - Taux de morbidité et de mortalité très faible et non supérieure à la chirurgie - Absence de sternotomie - Diminution de la durée de l'hospitalisation et surtout de la période de convalescence, le patient pouvant reprendre une activité dès son retour à domicile Certains experts émettent néanmoins des doutes quant à l'innocuité à long terme de la méthode, les zones nécrotiques pouvant servir de terrain arythmogène. Pour ces raisons, la méthode n'est pas recommandée chez les patients de moins de 40 ans (6,8). Le risque majeur de l'alcoolisation du septum proximal réside dans l'induction d'un bloc atrio-ventriculaire complet chimique, le noeud atrio-ventriculaire étant justement situé dans cette région. Ce risque augmente avec la quantité d'alcool administrée et nécessite, si persistance après trois jours, l'implantation d'un pacemaker à demeure. Selon les centres, le taux d'implantation d'un stimulateur varie ainsi entre 7% et 20% (7,14,20). L'efficacité clinique et l'incidence des complications est donc en partie liée à la compétence technique et à l'expérience de l'opérateur (7,14), mais aussi aux choix des patients. Il peut donc varier grandement selon les centres médicaux. L'étude proposée vise à analyser les résultats de l'alcoolisation obtenus à Lausanne, jusqu'à présent pas encore été étudiés, et à les comparer à ceux de la littérature.

Cardiac magnetic resonance imaging and computed tomography in ischemic cardiomyopathy: an update

Abstract Ischemic cardiomyopathy is one of the major health problems worldwide, representing a significant part of mortality in the general population nowadays. Cardiac magnetic resonance imaging (CMRI) and cardiac computed tomography (CCT) are noninvasive imaging methods that serve as useful tools in the diagnosis of coronary artery disease and may also help in screening individuals with risk factors for developing this illness. Technological developments of CMRI and CCT have contributed to the rise of several clinical indications of these imaging methods complementarily to other investigation methods, particularly in cases where they are inconclusive. In terms of accuracy, CMRI and CCT are similar to the other imaging methods, with few absolute contraindications and minimal risks of adverse side-effects. This fact strengthens these methods as powerful and safe tools in the management of patients. The present study is aimed at describing the role played by CMRI and CCT in the diagnosis of ischemic cardiomyopathies.

Clinical characterization of chronic chagasic cardiomyopathy in dogs

On the American continent, almost 15 million people are affected by Chagas disease, resulting in important economic and social damages. Dogs are considered to be an excellent experimental model to study Chagas' disease; as a result, in this research, the characterization of cardiovascular abnormalities was performed in dogs experimentally infected with Trypanosoma cruzi (the Colombian strain) that were at chronic stage. Thirteen adult female dogs were evaluated by electrocardiographic, echocardiographic, hematological and biochemical analyses in the chronic phase. For the electrocardiographic studies, respiratory sinus arrhythmia was the predominant rhythm during the entire research period (49.55% to 67%), with a low prevalence of right bundle branch block (0-13%) and first-degree atrioventricular block (0-14%). The spectral Doppler echocardio-graphy showed E and A mitral wave reversal (0.71±0.17), confirming the diastolic dysfunction present in all dogs. An increase in the enzymes activities was detected in the serum analysis, indicating myocardial injury by the infection. Six dogs died during the follow-up. In this way, the clinical characterization of experimentally infected dogs, as described here, increases the knowledge and allows for recognition of the behavioural modifications present in Chagas' disease in affected dogs.

Cytokine production profile of heart-infiltrating T cells in Chagas' disease cardiomyopathy

The hallmark of chronic Chagas' disease cardiomyopathy (CCC) is the finding of a T cell-rich inflammatory mononuclear cell infiltrate in the presence of extremely few parasites in the heart lesions. The scarcity of parasites in affected heart tissue casts doubt on the direct participation of Trypanosoma cruzi in CCC heart tissue lesions, and suggests the possible involvement of autoimmunity. The cells in the infiltrate are presumably the ultimate effectors of tissue damage, and there is evidence that such cells recognize cardiac myosin in molecular mimicry with T. cruzi proteins rather than primary reactivity to T. cruzi antigens (Cunha-Neto et al. (1996) Journal of Clinical Investigation, 98: 1709-1712). Recently, we have studied heart-infiltrating T cells at the functional level. In this short review we summarize the studies about the role of cytokines in human and experimental T. cruzi infection, along with our data on heart-infiltrating T cells in human Chagas' cardiomyopathy. The bulk of evidence points to a significant production of IFN-g and TNF-a which may be linked to T. cruzi-induced IL-12 production

Pressure and time dependence of the cardiopulmonary reflex response in patients with hypertensive cardiomyopathy

The first minutes of the time course of cardiopulmonary reflex control evoked by lower body negative pressure (LBNP) in patients with hypertensive cardiomyopathy have not been investigated in detail. We studied 15 hypertensive patients with left ventricular dysfunction (LVD) and 15 matched normal controls to observe the time course response of the forearm vascular resistance (FVR) during 3 min of LBNP at -10, -15, and -40 mmHg in unloading the cardiopulmonary receptors. Analysis of the average of 3-min intervals of FVR showed a blunted response of the LVD patients at -10 mmHg (P = 0.03), but a similar response in both groups at -15 and -40 mmHg. However, using a minute-to-minute analysis of the FVR at -15 and -40 mmHg, we observed a similar response in both groups at the 1st min, but a marked decrease of FVR in the LVD group at the 3rd min of LBNP at -15 mmHg (P = 0.017), and -40 mmHg (P = 0.004). Plasma norepinephrine levels were analyzed as another neurohumoral measurement of cardiopulmonary receptor response to LBNP, and showed a blunted response in the LVD group at -10 (P = 0.013), -15 (P = 0.032) and -40 mmHg (P = 0.004). We concluded that the cardiopulmonary reflex response in patients with hypertensive cardiomyopathy is blunted at lower levels of LBNP. However, at higher levels, the cardiopulmonary reflex has a normal initial response that decreases progressively with time. As a consequence of the time-dependent response, the cardiopulmonary reflex response should be measured over small intervals of time in clinical studies.

Proteomic inventory of myocardial proteins from patients with chronic Chagas' cardiomyopathy

Chronic Chagas' disease cardiomyopathy (CCC) is an often fatal outcome of Trypanosoma cruzi infection, with a poorer prognosis than other cardiomyopathies. CCC is refractory to heart failure treatments, and is the major indication of heart transplantation in Latin America. A diffuse myocarditis, plus intense myocardial hypertrophy, damage and fibrosis, in the presence of very few T. cruzi forms, are the histopathological hallmarks of CCC. To gain a better understanding of the pathophysiology of CCC, we analyzed the protein profile in the affected CCC myocardium. Homogenates from left ventricular myocardial samples of end-stage CCC hearts explanted during heart transplantation were subjected to two-dimensional electrophoresis with Coomassie blue staining; protein identification was performed by MALDI-ToF mass spectrometry and peptide mass fingerprinting. The identification of selected proteins was confirmed by immunoblotting. We demonstrated that 246 proteins matched in gels from two CCC patients. They corresponded to 112 distinct proteins. Along with structural/contractile and metabolism proteins, we also identified proteins involved in apoptosis (caspase 8, caspase 2), immune system (T cell receptor ß chain, granzyme A, HLA class I) and stress processes (heat shock proteins, superoxide dismutases, and other oxidative stress proteins). Proteins involved in cell signaling and transcriptional factors were also identified. The identification of caspases and oxidative stress proteins suggests the occurrence of active apoptosis and significant oxidative stress in CCC myocardium. These results generated an inventory of myocardial proteins in CCC that should contribute to the generation of hypothesis-driven experiments designed on the basis of the classes of proteins identified here.

Collagen content, but not the ratios of collagen type III/I mRNAs, differs among hypertensive, alcoholic, and idiopathic dilated cardiomyopathy

Cardiac interstitial fibrosis may contribute to ventricular dysfunction and the prognosis of patients with dilated cardiomyopathy. The objective of the present study was to determine if total myocardial collagen content and collagen type III/I (III/I ratio) mRNAs differ in hypertensive, alcoholic, and idiopathic dilated cardiomyopathy subjects. Echocardiography and exercise cardiopulmonary testing were performed in patients with idiopathic (N = 22), hypertensive (N = 12), and alcoholic (N = 11) dilated cardiomyopathy. Morphometric analysis of collagen was performed in fragments obtained by endomyocardial biopsy with picrosirius red staining. The collagen III/I ratio was determined by reverse transcription polymerase chain reaction. Samples of controls (N = 10) were obtained from autopsy. Echocardiographic variables and maximal oxygen uptake were not different among dilated cardiomyopathy groups. Collagen was higher in all dilated cardiomyopathy groups (idiopathic, hypertensive and alcoholic, 7.36 ± 1.09%) versus controls (1.12 ± 0.18%), P < 0.05. Collagen was lower in idiopathic dilated cardiomyopathy (4.97 ± 0.83%) than hypertensive (8.50 ± 1.11%) and alcoholic (10.77 ± 2.09%) samples (P < 0.005 for both). The collagen III/I ratio in all samples from dilated cardiomyopathy patients was higher compared to that in controls (0.29 ± 0.04, P < 0.05) but was the same in the samples from idiopathic (0.77 ± 0.07), hypertensive (0.75 ± 0.07), and alcoholic (0.81 ± 0.16) dilated cardiomyopathy groups. Because of the different physical properties of the types of collagen, the higher III/I ratio may contribute to progressive ventricular dilation and dysfunction in dilated cardiomyopathy patients.

A safety and feasibility study of cell therapy in dilated cardiomyopathy

The aim of this study was to determine if bone marrow mononuclear cell (BMMC) transplantation is safe for moderate to severe idiopathic dilated cardiomyopathy (IDC). Clinical trials have shown that this procedure is safe and effective for ischemic patients, but little information is available regarding non-ischemic patients. Twenty-four patients with IDC, optimized therapy, age 46 ± 11.6 years, 17 males, NYHA classes II-IV, and left ventricular ejection fraction <35% were enrolled in the study. Clinical evaluation at baseline and 6 months after stem cell therapy to assess heart function included echocardiogram, magnetic resonance imaging, cardiopulmonary test, Minnesota Quality of Life Questionnaire, and NYHA classification. After cell transplantation 1 patient showed a transient increase in enzyme levels and 2 patients presented arrhythmias that were reversed within 72 h. Four patients died during follow-up, between 6 and 12 weeks after therapy. Clinical evaluation showed improvement in most patients as reflected by statistically significant decreases in Minnesota Quality of Life Questionnaire (63 ± 17.9 baseline vs 28.8 ± 16.75 at 6 months) and in class III-IV NYHA patients (18/24 baseline vs 2/20 at 6 months). Cardiopulmonary exercise tests demonstrated increased peak oxygen consumption (12.2 ± 2.4 at baseline vs 15.8 ± 7.1 mL·kg-1·min-1 at 6 months) and walked distance (377.2 ± 85.4 vs 444.1 ± 77.9 m at 6 months) in the 6-min walk test, which was not accompanied by increased left ventricular ejection fraction. Our findings indicate that BMMC therapy in IDC patients with severe ventricular dysfunction is feasible and that larger, randomized and placebo-controlled trials are warranted.

Cell therapy in dilated cardiomyopathy: from animal models to clinical trials

Dilated cardiomyopathy can be the end-stage form and common denominator of several cardiac disorders of known cause, such as hypertensive, ischemic, diabetic and Chagasic diseases. However, some individuals have clinical findings, such as an increase in ventricular chamber size and impaired contractility (classical manifestations of dilated cardiomyopathy) even in the absence of a diagnosed primary disease. In these patients, dilated cardiomyopathy is classified as idiopathic since its etiology is obscure. Nevertheless, regardless of all of the advances in medical, pharmacological and surgical procedures, the fate of patients with dilated cardiomyopathy (of idiopathic or of any other known cause) is linked to arrhythmic episodes, severe congestive heart failure and an increased risk of sudden cardiac death. In this review, we will summarize present data on the use of cell therapies in animal models of dilated cardiomyopathies and will discuss the few clinical trials that have been published so far involving patients affected by this disease. The animal models discussed here include those in which the cardiomyopathy is produced by genetic manipulation and those in which disease is induced by chemical or infectious agents. The specific model used clearly creates restrictions to translation of the proposed cell therapy to clinical practice, insofar as most of the clinical trials performed to date with cell therapy have used autologous cells. Thus, translation of genetic models of dilated cardiomyopathy may have to wait until the use of allogeneic cells becomes more widespread in clinical trials of cell therapies for cardiac diseases.

Normal skin and hypertrophic scar fibroblasts differentially regulate collagen and fibronectin expression as well as mitochondrial membrane potential in response to basic fibroblast growth factor

Basic fibroblast growth factor (bFGF) regulates skin wound healing; however, the underlying mechanism remains to be defined. In the present study, we determined the effects of bFGF on the regulation of cell growth as well as collagen and fibronectin expression in fibroblasts from normal human skin and from hypertrophic scars. We then explored the involvement of mitochondria in mediating bFGF-inducedeffects on the fibroblasts. We isolated and cultivated normal and hypertrophic scar fibroblasts from tissue biopsies of patients who underwent plastic surgery for repairing hypertrophic scars. The fibroblasts were then treated with different concentrations of bFGF (ranging from 0.1 to 1000 ng/mL). The growth of hypertrophic scar fibroblasts became slower with selective inhibition of type I collagen production after exposure to bFGF. However, type III collagen expression was affected in both normal and hypertrophic scar fibroblasts. Moreover, fibronectin expression in the normal fibroblasts was up-regulated after bFGF treatment. bFGF (1000 ng/mL) also induced mitochondrial depolarization in hypertrophic scar fibroblasts (P < 0.01). The cellular ATP level decreased in hypertrophic scar fibroblasts (P < 0.05), while it increased in the normal fibroblasts following treatment with bFGF (P < 0.01). These data suggest that bFGF has differential effects and mechanisms on fibroblasts of the normal skin and hypertrophic scars, indicating that bFGF may play a role in the early phase of skin wound healing and post-burn scar formation.