Peripheral Blood Mononuclear Cells Mitochondrial Respiration and Superoxide Anion after Heart Transplantation.

INTRODUCTION: The mitochondrial function of circulating peripheral blood mononuclear cells (PBMCs) is an interesting new approach to cardiac diseases. Thus, PBMC's mitochondrial respiration decreases in relation to heart failure severity. However, no data are available on heart-transplanted patients (Htx). POPULATION AND METHODS: We determined PBMCs mitochondrial respiration by high-resolution respirometry (Oroboros Instruments) and superoxide anion production using electron paramagnetic resonance (Bruker-Biospin) in 20 healthy subjects and 20 matched Htx and investigated clinical, biological, echocardiographic, coronarography and biopsy characteristics. RESULTS: PBMCs mitochondrial respiratory chain complex II respiration was decreased in Htx (4.69 ± 0.84 vs. 7.69 ± 1.00 pmol/s/million cell in controls and Htx patients, respectively; p = 0.007) and complex IV respiration was increased (24.58 ± 2.57 vs. 15.68 ± 1.67 pmol/s/million cell; p = 0.0035). Superoxide anion production was also increased in Htx (1.47 ± 0.10 vs. 1.15 ± 0.10 µmol/min; p = 0.041). The leucocyte-to-lymphocyte ratio was increased in Htx, whom complex II correlated with leucocyte number (r = 0.51, p = 0.02) and with the left ventricular posterior wall peak early diastolic myocardial velocity (r = -0.62, p = 0.005). Complex IV was increased in the two patients with acute rejection and correlated negatively with Htx's isovolumetric relation time (r = -0.45, p = 0.045). DISCUSSION: Although presenting with normal systolic function, Htx demonstrated abnormal PBMC's mitochondrial respiration. Unlike immunosuppressive therapies, subclinical diastolic dysfunction might be involved in these changes. Additionally, lymphopenia might reduce complex II, and acute rejection enhances complex IV respirations. CONCLUSION: PBMC's mitochondrial respiration appears modified in Htx, potentially linked to cellular shift, mild diastolic dysfunction and/or acute rejection.

Cyclic nucleotide phosphodiesterases: New targets in the metabolic syndrome?

Metabolic diseases have a tremendous impact on human morbidity and mortality. Numerous targets regulating adenosine monophosphate kinase (AMPK) have been identified for treating the metabolic syndrome (MetS), and many compounds are being used or developed to increase AMPK activity. In parallel, the cyclic nucleotide phosphodiesterase families (PDEs) have emerged as new therapeutic targets in cardiovascular diseases, as well as in non-resolved pathologies. Since some PDE subfamilies inactivate cAMP into 5'-AMP, while the beneficial effects in MetS are related to 5'-AMP-dependent activation of AMPK, an analysis of the various controversial relationships between PDEs and AMPK in MetS appears interesting. The present review will describe the various PDE families, AMPK and molecular mechanisms in the MetS and discuss the PDEs/PDE modulators related to the tissues involved, thus supporting the discovery of original molecules and the design of new therapeutic approaches in MetS.

Critical Limb Ischaemia Exacerbates Mitochondrial Dysfunction in ApoE-/- Mice Compared with ApoE+/+ Mice, but N-acetyl Cysteine still Confers Protection.

OBJECTIVES: The current study was performed in order to determine the influence of hypercholesterolaemia on critical limb ischaemia (CLI) and whether targeting oxidative stress by antioxidant therapies such as N-acetyl cysteine (NAC), considered to be a direct scavenger of reactive oxygen species, could confer muscle protection. METHODS: Apolipoprotein E (ApoE)-/- mice (n = 9, 29 weeks old) and their genetic controls ApoE+/+ mice (n = 9, 29 weeks old) were submitted to sequential right femoral and iliac ligations; the left limb served as control. ApoE+/+ mice were divided into two groups: Group 1 (n = 4) and Group 2 (n = 5); as well as ApoE-/- mice: Group 3 (n = 3), and Group 4 (n = 6). NAC treatment was administered to Groups 2 and 4 in drinking water. Mice were sacrificed on Day 40 and gastrocnemius muscles were harvested to study mitochondrial respiration by oxygraphy, calcium retention capacity by spectrofluorometry, and production of reactive oxygen species by electron paramagnetic resonance. RESULTS: CLI associated with ApoE deficiency resulted in more severe mitochondrial dysfunction: maximum oxidative capacity and calcium retention capacity were decreased (-42.9% vs. -25.1%, p = .010; and -73.1% vs. -40.3%, p = .003 respectively) and production of reactive oxygen species was enhanced (+63.6% vs. +41.4%, p = .03) in ApoE-/- mice compared with ApoE+/+ mice respectively. Antioxidant treatment restored oxidative capacity, calcium retention capacity and decreased production of reactive oxygen species in both mice strands. CONCLUSIONS: In this small murine study, hypercholesterolaemia exacerbated mitochondrial dysfunction, as clinically expected; but antioxidant therapy appeared protective, which is counter to clinical experience. Further work is clearly needed.

Effects of a High Fat Meal Associated with Water, Juice, or Champagne Consumption on Endothelial Function and Markers of Oxidative Stress and Inflammation in Young, Healthy Subjects.

Endothelial dysfunction (ED), often linked to hypertriglyceridemia, is an early step of atherosclerosis. We investigated, in a randomized cross-over study, whether high-fat meal (HFM)-induced ED might be reduced by fruit juice or champagne containing polyphenols. Flow-mediated dilatation (FMD) and biological parameters (lipid profile, glycemia, inflammation, and oxidative stress markers) were determined before and two and three hours after the HFM in 17 healthy young subjects (24.6 ± 0.9 years) drinking water, juice, or champagne. Considering the entire group, despite significant hypertriglyceridemia (from 0.77 ± 0.07 to 1.41 ± 0.18 mmol/L, p < 0.001) and a decrease in Low Density Lipoprotein (LDL), the FMD was not impaired. However, the FMD decreased in 10 subjects (from 10.73 ± 0.95 to 8.1 3± 0.86 and 8.07 ± 1.16%; p < 0.05 and p < 0.01; 2 and 3 hours, respectively, after the HFM), without concomitant change in concentration reactive protein or reactive oxygen species, but with an increase in glycemia. In the same subjects, the FMD did not decrease when drinking juice or champagne. In conclusion, HFM can impair the endothelial function in healthy young subjects. Fruit juice, rich in anthocyanins and procyanidins, or champagne, rich in simple phenolic acids, might reduce such alterations, but further studies are needed to determine the underlying mechanisms, likely involving polyphenols.

N-Acetyl Cysteine Restores Limb Function, Improves Mitochondrial Respiration, and Reduces Oxidative Stress in a Murine Model of Critical Limb Ischaemia.

OBJECTIVE/BACKGROUND: The aim of this study was to investigate whether antioxidant therapy might decrease oxidative stress related deleterious effects in the setting of critical limb ischaemia (CLI). METHODS: Twenty Swiss mice were submitted to sequential right femoral and iliac ligatures; the left limb served as control. The mice were assigned to two groups: in the first group (no-treatment group, n = 10) no treatment was administered; in the second group (N-acetyl cysteine [NAC] group, n = 10) NAC was administered by dissolution in drinking water for 4 weeks, starting on day 7, when CLI was effective. Clinical and functional scores were assessed by two blinded investigators. Mice were killed on day 40 and mitochondrial respiratory chain complex activities, calcium retention capacity, oxidative stress, and histological analysis were analysed. RESULTS: Ischaemic muscles in the no-treatment group showed significantly impaired mitochondrial respiration and calcium retention capacity, with increased production of reactive oxygen species; but no statistical difference was noticed when comparing ischaemic muscles in the NAC group (n = 10) to contralateral muscles (n = 10) and to control muscles in the no-treatment group (n = 10). Ischaemic muscles in the no-treatment group exhibited myopathic features such as wider range in fibre size, rounded shape, centrally located nuclei, and smaller cross sectional areas, but none of these features were observed in contralateral muscles or in NAC-group muscles (ischaemic or controls). CONCLUSION: Targeting inhibition of oxidative stress may be a potential therapeutic strategy for muscle protection in CLI and might be considered as potential adjunctive therapy to revascularisation procedures.

Effects of cyclic nucleotide phosphodiesterases (PDEs) on mitochondrial skeletal muscle functions.

Mitochondria play a critical role in skeletal muscle metabolism and function, notably at the level of tissue respiration, which conduct muscle strength as well as muscle survival. Pathological conditions induce mitochondria dysfunctions notably characterized by free oxygen radical production disturbing intracellular signaling. In that way, the second messengers, cyclic AMP and cyclic GMP, control intracellular signaling at the physiological and transcription levels by governing phosphorylation cascades. Both nucleotides are specifically and selectively hydrolyzed in their respective 5'-nucleotide by cyclic nucleotide phosphodiesterases (PDEs), which constitute a multi-genic family differently tissue distributed and subcellularly compartmentalized. These PDEs are presently recognized as therapeutic targets for cardiovascular, pulmonary, and neurologic diseases. However, very few data concerning cyclic nucleotides and PDEs in skeletal muscle, specifically in mitochondria, are reported in the literature. The knowledge of PDE implication in mitochondrial signaling would be helpful for resolving critical mitochondrial dysfunctions in skeletal muscle.

Remote and local ischemic preconditioning equivalently protects rat skeletal muscle mitochondrial function during experimental aortic cross-clamping.

OBJECTIVE: This study investigated whether remote (rIPC) and local ischemic preconditioning (IPC) similarly limit skeletal muscle dysfunction induced by aortic cross-clamping. METHODS: Rats were divided in three groups: the sham-operated control group (C) underwent surgery without clamping. The ischemia-reperfusion group (IR) had 3 hours of ischemia induced by aortic clamping and collateral vessels ligation, followed by 2 hours of reperfusion. The IPC group had, before prolonged ischemia, three bouts of 10 minutes of ischemia and 10 minutes of reperfusion on the right hind limb. Thus, right hind limbs had local IPC and left hind limbs had rIPC. Complexes I, II, III, and IV activities of the mitochondrial respiratory chain of the gastrocnemius muscle were measured using glutamate-malate (V(max)), succinate (V(succ)), and N,N,N',N'-tetramethyl-p-phenylenediamine dihydrochloride (TMPD)-ascorbate (V(TMPD)). Expressions of genes involved in apoptosis (Bax, Bcl-2) and antioxidant defense (superoxide dismutase 1 [SOD 1], SOD2, glutathione peroxidase [GPx]) were determined by quantitative real-time polymerase chain reaction. Glutathione was also measured. RESULTS: Right and left hind limb mitochondrial functions were similar in controls and after IR. IR reduced V(max) (-21.2%, 6.6 ± 1 vs 5.2 ± 1 µmol O(2)/min/g dry weight, P = .001), V(succ) (-22.2%, P = .032), and V(TMPD) (-22.4%, P = .033), and increased Bax (63.4%, P = .020) and Bax/Bcl-2 ratio (+84.6%, P = .029). SODs and GPx messenger RNA were not modified, but glutathione tended to be decreased after IR. Local IPC and rIPC counteracted similarly these deleterious effects, restoring mitochondrial maximal oxidative capacities and normalizing Bax, the Bax/Bcl-2 ratio, and glutathione. CONCLUSIONS: Remote ischemic preconditioning protection against IR injury is equivalent to that achieved by local IPC. It might deserve a broader use in clinical practice. CLINICAL RELEVANCE: Acute and chronic ischemia induce mitochondrial dysfunction in human skeletal muscles, and improving muscle mitochondrial function improves subjects' status. Compared with local ischemic preconditioning (IPC), remote IPC (rIPC) appears easier to perform and is safer for the vessel and territory involved in ischemic injury. This study demonstrates that the muscle protection afforded by rIPC is equivalent to that achieved by IPC. Acknowledging that IPC procedures should be specifically adapted to patient characteristics to be successful, our results support a broader use of rIPC in the setting of vascular surgery.

Emergency management of a particular massive pulmonary embolism...

Cardiac intracavitary metastasis is very uncommon. In a 55-year-old man presenting with a massive pulmonary embolism pattern, transthoracic echocardiography (TTE) allowed us to visualize an isolated right ventricular metastasis extended into the pulmonary trunk. It led to the discovery of a primary testis embryonal carcinoma. No intracaval and right atrial localization was observed. Despite an urgent complete cardiac metastasis resection and concomitant orchidectomy, TTE showed on postoperative day 6 an uncommon total intracardiac regrowth spreading again to the pulmonary trunk. Combination chemotherapy (etoposide, cisplatin, and bleomycin) was immediately undertaken. This is the first well-documented case of an isolated right ventricular germ-cell cancer metastasis extended into the pulmonary trunk, without intracaval and right atrial involvement, where the outcome was marked with immediate regrowth despite cardiac surgery and orchidectomy. In conclusion, TTE should be considered alongside germ-cell cancer standard staging procedures.