ABSTRACT
The term GETomics has been recently proposed to illustrate that human health and disease are actually the final outcome of many dynamic, interacting and cumulative gene (G) - environment (E) interactions that occur through the lifetime (T) of the individual. According to this new paradigm, the final outcome of any GxE interactions depends on both the age of the individual at which such GxE interaction occurs as well as on the previous, cumulative history of previous GxE interactions through the induction of epigenetic changes and immune memory (both lasting overtime). Following this conceptual approach, our understanding of the pathogenesis of chronic obstructive pulmonary disease (COPD) has changed dramatically. Traditionally believed to be a self-inflicted disease induced by tobacco smoking occurring in older men and characterized by an accelerated decline of lung function with age, now we understand that there are many other risk factors associated with COPD, that it occurs also in females and young individuals, that there are different lung function trajectories through life, and that COPD is not always characterized by accelerated lung function decline. In this paper we discuss how a GETomics approach to COPD may open new perspectives to better understand its relationship with exercise limitation and the ageing process.
Subject(s)
Pulmonary Disease, Chronic Obstructive , Male , Female , Humans , Aged , Pulmonary Disease, Chronic Obstructive/complications , Aging/genetics , Risk Factors , Lung , Spirometry/adverse effectsABSTRACT
PURPOSE: Bariatric surgery, as Roux-en-Y gastric bypass (RYGB), laparoscopic gastric banding (LGB), and laparoscopic sleeve gastrectomy (LSG), is considered the gold standard treatment to achieve long-term weight loss in severe obesity. In patients who fail to maintain the achieved weight, pharmacological treatment may be required. Here, we reported our real-life experience on the efficacy of liraglutide therapy in 62 patients who regained weight after bariatric surgery. METHODS: We retrospectively evaluated 62 (60 F-2 M; mean age: 43.6 ± 9.9 years) patients received liraglutide for weight loss after bariatric surgery (17 RYGB, 22 LGB, and 23 LSG). Body mass index (BMI) before and after surgery was, respectively, of 45.4 ± 5.5 kg/m2 and 29.5 ± 4.9 kg/m2. Patients were followed up from 2016 until 2021. Liraglutide was administered after weight regain once-daily subcutaneously at starting dose of 0.6 mg and with weekly increases up to 3.0 mg. Treatments were administered when a weight regain of 10-15% occurred after reaching a minimum weight loss from bariatric surgery or if weight loss after bariatric surgery was unsatisfactory. RESULTS: After a mean of 70.7 ± 43.7 months from any bariatric surgery, all patients started liraglutide therapy. At this time, mean BMI was 34.2 ± 4.8 kg/m2 (mean increased BMI: 4.7 ± 2.8 kg/m2). After a mean of 10.5 ± 4.4 months from the beginning of liraglutide, 9 patients achieved normal weight (BMI 24.1 ± 0.9 kg/m2), and 28 were overweight (BMI 26.9 ± 1.6 kg/m2). Twenty patients achieved grade I (BMI 32.1 ± 1.5 kg/m2), 5 grade II (BMI 37.3 ± 2.0 kg/m2) obesity, and none had grade III obesity (mean BMI change: - 5.1 ± 2.5 kg/m2). The treatment was well tolerated, and no serious adverse events were recorded. CONCLUSION: These data confirm the efficacy and safety of liraglutide in patients who experienced weight regain after bariatric surgery. Considering the long-term follow-up, patients should be followed up regularly and the pharmacological treatment should be adapted to the weight fluctuations observed during the clinical history. LEVEL OF EVIDENCE: V. Opinions of authorities, based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees.
Subject(s)
Bariatric Surgery , Gastric Bypass , Laparoscopy , Obesity, Morbid , Adult , Gastrectomy/adverse effects , Gastric Bypass/adverse effects , Humans , Liraglutide/therapeutic use , Middle Aged , Obesity/etiology , Obesity, Morbid/drug therapy , Obesity, Morbid/surgery , Retrospective Studies , Treatment Outcome , Weight Gain , Weight LossABSTRACT
Blastic plasmacytoid dendritic cell neoplasm (BPDCN), an extremely rare and aggressive tumor, derives from plasmacytoid dendritic cell precursors and is characterized by CD4 and CD56 positivity accompanied by the expression of isolated myeloid, B- or T-cell lineage markers. Despite the recent introduction of specific targeted therapies, prognosis is still poor with a median overall survival of one year, and allogeneic bone marrow transplantation remains the only curative treatment in eligible patients. In this series, we described two cases of adult BPDCN treated with high dose cytarabine and methotrexate and autologous hematopoietic stem cell transplantation, or fludarabine, cytarabine, and idarubicin achieving the first a complete lasting remission, while the second only a transient improvement in skin lesions.
ABSTRACT
In the present study we describe the molecular characterization of the two paralogous mitochondrial peroxiredoxins from Trematomus bernacchii, a teleost that plays a pivotal role in the Antarctic food chain. The two putative amino acid sequences were compared with orthologs from other fish, highlighting a high percentage of identity and similarity with the respective variant, in particular for the residues that are essential for the characteristic peroxidase activity of these enzymes. The temporal expression of Prdx3 and Prdx5 mRNAs in response to short-term thermal stress showed a general upregulation of prdx3, suggesting that this isoform is the most affected by temperature increase. These data, together with the peculiar differences between the molecular structures of the two mitochondrial Prdxs in T. bernacchii as well as in the tropical species Stegastes partitus, suggest an adaptation that allowed these poikilothermic aquatic vertebrates to colonize very different environments, characterized by different temperature ranges.
Subject(s)
Mitochondria/enzymology , Perciformes/metabolism , Peroxiredoxins , Amino Acid Sequence , Animals , Antarctic Regions , Fish Proteins/classification , Fish Proteins/metabolism , Gene Expression , Global Warming , Peroxiredoxins/classification , Peroxiredoxins/metabolism , Phylogeny , Protein Isoforms , TemperatureSubject(s)
AIDS-Related Opportunistic Infections/complications , AIDS-Related Opportunistic Infections/pathology , Brain/diagnostic imaging , HIV Seropositivity/diagnosis , HIV-1/isolation & purification , Intracranial Hemorrhages/pathology , Toxoplasmosis, Cerebral/complications , Toxoplasmosis, Cerebral/pathology , AIDS-Related Opportunistic Infections/diagnostic imaging , Adult , Brain/pathology , HIV Seropositivity/complications , HIV-1/genetics , Humans , Intracranial Hemorrhages/diagnostic imaging , Intracranial Hemorrhages/etiology , Magnetic Resonance Imaging , Male , Tomography, X-Ray Computed , Toxoplasmosis, Cerebral/diagnosis , Toxoplasmosis, Cerebral/diagnostic imagingABSTRACT
INTRODUCTION: Stenotrophomonas Malthophilia (SM) is generally considered a nosocomial pathogen but it has also been reported as a cause of community-acquired systemic infection. We reported a rare case of SM multi-organ infection involving the liver and the left ocular region. PRESENTATION OF THE CASE: A 64 years old man presented with fever for 4 days and acute blindness of the left eye. We performed an abdomen and head CT scan that identified respectively a liver lesion in central region, likely a hepatic abscess, and inflammation process involving the left eye. After 5 days of antibiotic therapy, no improvement of the clinical condition was noted. A CT guided drainage of the hepatic abscess was performed. SM was identified in the content of the drain and selected antibiotic therapy with combination of tygecycline and TMP-SMX was immediately initiated.After 15 days of the selected therapy, the hepatic abscess and the left eye infection were completely resolved but unfortunately the patient reported permanent blindness. DISCUSSION: Several studies identified most of the SM infections as nosocomial, however that can be excluded in this case because the patient presented signs of severe systemic infection 72 h before the hospitalization. The conservative treatment, with a combination of CT guided drainage and selected antibiotic therapy, gave good results. CONCLUSION: Although SM is thought to be a nosocomial pathogen, it can be involved in severe systemic sepsis affecting different organs outside the hospital setting. Fortunately, the combination of tigecycline with TMP-SMX seems to be the best therapeutic option.
ABSTRACT
In both humans and animals, essential hypertension acts as a risk factor for subclinical kidney damage and precedes renal dysfunction. Several lines of evidence indicate that hypertension and oxidative stress are closely related. The increase in vascular oxidative stress plays a key role in the pathophysiological consequences of hypertension, including kidney disease. Our study examined this issue in spontaneously hypertensive rat (SHR), a reliable model of essential hypertension. We used SHR 20 weeks old when hypertension is stably developed, vascular remodeling started, but kidney function is preserved. We examined plasmatic pro-oxidant and antioxidant status showing a significant alteration in oxidative balance in SHR. As index of oxidative damage, we evaluated lipid peroxidation in kidney, liver, and skeletal muscle, detecting a significant rise in lipid peroxidation levels in all SHR tissues, particularly relevant in kidney. In addition, we analyzed the expression of cytoplasmic antioxidant enzymes, superoxide dismutase 1 (SOD1) and glutatione S-tranferasi P1 (GSTP1). In SHR liver, SOD1 expression slight increased while we have not detected any variation in other tissues. Concerning GSTP1, SHR renal tissues did not display variations in enzyme expression, while in the other tissues, we observed a significant increase in both monomeric and pro-apoptotic dimeric form of the enzyme. By analyzing apoptotic signal, we founded c-Jun N-terminal kinase (JNK) activation in all SHR tissues, but only kidney presented extrinsic apoptotic pathway activation. Our results suggest that, in hypertensive animals with preserved renal function, despite the remarkable oxidative damage of renal tissues, only the extrinsic apoptotic pathway is activated.
Subject(s)
Apoptosis/physiology , Hypertension/complications , Kidney Diseases/etiology , Oxidative Stress/physiology , Animals , Antioxidants/metabolism , Disease Models, Animal , Essential Hypertension , Glutathione S-Transferase pi/metabolism , Hypertension/metabolism , Hypertension/pathology , Kidney/metabolism , Kidney Diseases/metabolism , Kidney Diseases/pathology , Lipid Peroxidation/physiology , Liver/metabolism , Male , Rats, Inbred SHR , Signal Transduction/physiology , Superoxide Dismutase-1/metabolismABSTRACT
OBJECTIVES: The objective of this study was to perform a systematic review and meta-analysis of the literature to evaluate the efficacy and safety of therapies for cerebral toxoplasmosis in HIV-infected adults. The pyrimethamine plus sulfadiazine (P-S) combination is considered the mainstay therapy for cerebral toxoplasmosis and pyrimethamine plus clindamycin (P-C) is the most common alternative treatment. Although trimethoprim-sulfamethoxazole (TMP-SMX) has potential advantages, its use is infrequent. METHODS: We searched PubMed and four other databases to identify randomized controlled trials (RCTs) and cohort studies. Two independent reviewers searched the databases, identified studies and extracted data. Risk ratios (RRs) were pooled across studies using random-effects models. RESULTS: Nine studies were included (five RCTs, three retrospective cohort studies and one prospective cohort study). In comparison to P-S, treatment with P-C or TMP-SMX was associated with similar rates of partial or complete clinical response [P-C: RR 0.87; 95% confidence interval (CI) 0.70-1.08; TMP-SMX: RR 0.97; 95% CI 0.78-1.21], radiological response (P-C: RR 0.92; 95% CI 0.82-1.03), skin rash (P-C: RR 0.81; 95% CI 0.56-1.17; TMP-SMX: RR 0.17; 95% CI 0.02-1.29), gastrointestinal impairment (P-C: RR 5.16; 95% CI 0.66-40.11), and drug discontinuation because of adverse events (P-C: RR 0.32; 95% CI 0.07-1.47). Liver impairment was more frequent with P-S than P-C (P-C vs. P-S: RR 0.48; 95% CI 0.24-0.97). CONCLUSIONS: The current evidence fails to identify a superior regimen in terms of relative efficacy or safety for the treatment of HIV-associated cerebral toxoplasmosis. Use of TMP-SMX as preferred treatment may be consistent with the available evidence and other real-world considerations. Larger comparative studies are needed.
Subject(s)
Antiprotozoal Agents/adverse effects , Antiprotozoal Agents/therapeutic use , HIV Infections/complications , Toxoplasmosis, Cerebral/drug therapy , Trimethoprim, Sulfamethoxazole Drug Combination/adverse effects , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use , Adult , Clindamycin/adverse effects , Clindamycin/therapeutic use , Cohort Studies , Female , Humans , Male , Middle Aged , Pyrimethamine/adverse effects , Pyrimethamine/therapeutic use , Randomized Controlled Trials as Topic , Sulfadiazine/adverse effects , Sulfadiazine/therapeutic useABSTRACT
The main target of primary prevention is the identification of cardiovascular risk factors aimed at reducing of the adverse impact of modifiable factors, such as lifestyle and pharmacological treatments. In humans, an alteration of the oxidative status has been associated with several pathologies, including diabetes and cardiovascular diseases. However, the prognostic relevance of circulating oxidative stress biomarkers remains poorly understood. Our study explored, in a healthy population (n = 322), the relationship between oxidative status and cardiovascular risk factors. Here, we were successful in demonstrating that plasmatic oxidative status is significantly associated with traditional cardiovascular risk factors. We revealed a significant depletion in the efficacy of total plasma antioxidant barrier in high cardiovascular risk categories, and we confirmed an age-related alteration of oxidative status. The efficacy of total plasma antioxidant barrier is significantly depleted in relation to metabolic disorders. Interestingly, the cholesterol imbalance is the main factor in depleting the efficacy of total plasma antioxidant barrier. The oxidative status is also influenced by hypertension, and a slight increase in systolic blood pressure determines a highly significant effect. We showed that the first detectable event of a redox disturbance is the repairing intervention of the antioxidant barrier that is thus decreased as overutilized.
Subject(s)
Antioxidants/metabolism , Diabetes Mellitus/blood , Hypertension/blood , Adult , Female , Humans , Male , Middle Aged , Risk FactorsABSTRACT
Broadband single photons are usually considered not to couple efficiently to atomic gases because of the large mismatch in bandwidth. Contrary to this intuitive picture, here we demonstrate that the interaction of ultrashort single photons with a dense resonant atomic sample deeply modifies the temporal shape of their wave packet mode without degrading their nonclassical character, and effectively generates zero-area single-photon pulses. This is a clear signature of strong transient coupling between single broadband (THz-level) light quanta and atoms, with intriguing fundamental implications and possible new applications to the storage of quantum information.
ABSTRACT
The immunoglobulin E (IgE) are a key factor in the pathophysiology of allergic diseases and the important therapeutic role of an anti-IgE antibody was long envisioned. It took time and efforts to solve the safety problems related to the anaphylactogen capacity of anti-IgE, finally crowned by the introduction of the humanized, monoclonal anti-IgE antibody omalizumab. Currently, omalizumab is indicated, based on clear evidence of efficacy, only in severe allergic asthma not controlled by conventional treatment. However, a continuously increasing amount of literature shows that omalizumab is efficacious in a number of disorders concerning the upper and lower airway and the skin, and, most importantly, in anaphylaxis. The latter application was demonstrated successful in placebo-controlled trials and warrants for a new, life-saving, indication for omalizumab. Also, the systemic reactions precluding the performance of allergen immunotherapy, especially concerning Hymenoptera venom, were prevented by omalizumab treatment. The most surprising success of omalizumab regards clinical conditions thus far considered unrelated to IgE antibodies. This is true for intrinsic asthma and for idiopathic urticaria (demonstrated by a placebo-controlled trial), and angioedema, suggesting in these condition a pathophysiologic role of IgE. These observations support a off-label use of omalizumab in patients suffering from IgE-related pathologies other than asthma who are at risk of fatal events or are uncontrolled by the optimal standard treatment.
Subject(s)
Anti-Allergic Agents/therapeutic use , Antibodies, Anti-Idiotypic/therapeutic use , Antibodies, Monoclonal, Humanized/therapeutic use , Hypersensitivity/drug therapy , Immunoglobulin E/immunology , Humans , Hypersensitivity/blood , Hypersensitivity/immunology , Immunoglobulin E/blood , Off-Label Use , Omalizumab , Practice Guidelines as Topic , Signal Transduction/drug effectsABSTRACT
BACKGROUND AND AIMS: The anorexigenic glucagon-like peptide (GLP)-2 is produced by intestinal L cells and released in response to food intake. It affects intestinal function involving G-protein-coupled receptors. To verify whether GLP-2 acts as a cardiac modulator in mammals, we analysed, in the rat heart, the expression of GLP-2 receptors and the myocardial and coronary responses to GLP-2. METHODS AND RESULTS: GLP-2 receptors were detected on ventricular extracts by quantitative real-time polymerase chain reaction (Q-RT-PCR) and Western blotting. Cardiac GLP-2 effects were analysed on Langendorff perfused hearts. Intracellular GLP-2 signalling was investigated on Langendorff perfused hearts and by Western blotting and enzyme-linked immunosorbent assay (ELISA) on ventricular extracts. By immunoblotting and Q-RT-PCR, we revealed the expression of ventricular GLP-2 receptors. Perfusion analyses showed that GLP-2 induces positive inotropism at low concentration (10-12 mol l(-1)), and negative inotropism and lusitropism from 10 to 10 mol l(-1). It dose-dependently constricts coronaries. The negative effects of GLP-2 were independent from GLP-1 receptors, being unaffected by exendin-3 (9-39) amide. GLP-2-dependent negative action involves Gi/o proteins, associates with a reduction of intracellular cyclic adenosine monophosphate (cAMP), an increase in extracellular signal regulated kinases 1 and 2 (ERK1/2) and a decrease in phospholamban phosphorylation, but is independent from endothelial nitric oxide synthase (eNOS) and protein kinase G (PKG). Finally, GLP-2 competitively antagonised ß-adrenergic stimulation. CONCLUSIONS: For the first time, to our knowledge, we found that: (1) the rat heart expresses functional GLP-2 receptors; (2) GLP-2 acts on both myocardium and coronaries, negatively modulating both basal and ß-adrenergic stimulated cardiac performance; and (3) GLP-2 effects are mediated by G-proteins and involve ERK1/2.
Subject(s)
Glucagon-Like Peptide 2/pharmacology , Receptors, Glucagon/genetics , Receptors, Glucagon/metabolism , Animals , Blotting, Western , Cardiotonic Agents/pharmacology , Cyclic AMP/metabolism , Cyclic GMP-Dependent Protein Kinases/genetics , Cyclic GMP-Dependent Protein Kinases/metabolism , Enzyme-Linked Immunosorbent Assay , Gene Expression Regulation , Glucagon-Like Peptide-1 Receptor , Glucagon-Like Peptide-2 Receptor , Heart/drug effects , In Vitro Techniques , MAP Kinase Signaling System , Male , Nitric Oxide Synthase Type III/genetics , Nitric Oxide Synthase Type III/metabolism , Peptide Fragments/pharmacology , Phosphorylation , Rats , Rats, Wistar , Real-Time Polymerase Chain Reaction , Signal TransductionABSTRACT
The teleostean Channichthyidae (icefish), endemic stenotherms of the Antarctic waters, perennially at or near freezing, represent a unique example of disaptation among adult vertebrates for their loss of functional traits, particularly hemoglobin (Hb) and, in some species, cardiac myoglobin (Mb), once considered to be essential-life oxygen-binding chromoproteins. Conceivably, this stably frigid, oxygen-rich habitat has permitted high tolerance of disaptation, followed by subsequent adaptive recovery based on gene expression reprogramming and compensatory responses, including an alternative cardio-circulatory design, Hb-free blood and Mb-free cardiac muscle. This review revisits the functional significance of the multilevel cardio-circulatory compensations (hypervolemia, near-zero hematocrit and low blood viscosity, large bore capillaries, increased vascularity with great capacitance, cardiomegaly with very large cardiac output, high blood flow with low systemic pressure and systemic resistance) that counteract the challenge of hypoxemic hypoxia by increasing peripheral oxygen transcellular movement for aerobic tissues, including the myocardium. Reconsidered in the context of recent knowledge on both polar cold adaptation and the new questions related to the advent of nitric oxide (NO) biology, these compensations can be interpreted either according to the "loss-without-penalty" alternative, or in the context of an excessive environmental oxygen supply at low cellular cost and oxygen requirement in the cold. Therefore, rather than reflecting oxygen limitation, several traits may indicate structural overcompensation of oxygen supply reductions at cell/tissue levels. At the multilevel cardio-circulatory adjustments, NO is revealing itself as a major integrator, compensating disaptation with functional phenotypic plasticity, as illustrated by the heart paradigm. Beside NOS-dependent NO generation, recent knowledge concerning Hb/Mb interplay with NO and nitrite has revealed unexpected functions in addition to the classical respiratory role of these proteins. In fact, nitrite, a major biologic reservoir of NO, generates it through deohyHb- and deoxyMb-dependent nitrite reduction, thereby regulating hypoxic vasodilation, cellular respiration and signalling. We suggest that both Hb and Mb are involved as nitrite reductases under hypoxic conditions in a number of cardiocirculatory processes. On the whole, this opens new horizons in environmental and evolutionary physiology.
Subject(s)
Adaptation, Physiological/physiology , Perciformes/physiology , Acclimatization , Animals , Biological Evolution , Cardiovascular Physiological Phenomena , Cold Temperature , Heart/anatomy & histology , Heart/physiology , Hemoglobins/genetics , Homeostasis/physiology , Mitochondria, Heart , Myocardium/metabolism , Myoglobin/genetics , Nitric Oxide/metabolism , Nitric Oxide Synthase/physiology , Oxygen/blood , PhenotypeABSTRACT
Being the largest form of intravascular and tissue storage of nitric oxide (NO) and a signalling molecule itself, the nitrite anion (NO(2)(-)) has emerged as a key player in many biological processes. Since the heart is under an important NO-mediated autocrine-paracrine control, in mammals the cardiac effects of nitrite are under intensive investigation. In contrast, nothing is known in non-mammalian vertebrates. We evaluated nitrite influence on cardiac performance in the perfused beating heart of three different cold-blooded vertebrates, i.e. two teleost fishes, the temperate red-blooded Anguilla anguilla, the Antarctic stenotherm, hemoglobinless Chionodraco hamatus (icefish), and the frog Rana esculenta. We showed that, under basal conditions, in all animals nitrite influences cardiac mechanical performance, inducing negative inotropism in eel and frog, while being a positive inotrope in C. hamatus. In all species, these responses parallel the inotropic effects of authentic NO. We also demonstrated that the nitrite-dependent inotropic effects are i) dependent from NO synthase (NOS) activity in fish; ii) sensitive to NO scavenging in frog; iii) cGMP/PKG-dependent in both eel and frog. Results suggest that nitrite is an integral physiological source of NO and acts as a signalling molecule in lower vertebrate hearts, exerting relevant inotropic actions through different species-specific mechanisms.
Subject(s)
Anguilla/metabolism , Myocardial Contraction/drug effects , Nitrites/pharmacology , Perciformes/metabolism , Rana esculenta/metabolism , Animals , Antarctic Regions , Female , Male , Myocardium/metabolism , Oceans and SeasABSTRACT
In the present study, we evaluated the transduction pathways involved in the cardiac effects elicited by 17beta-estradiol (E2) on the isolated, Langendorff perfused male Wistar rat heart. E2 and selective agonists for ERalpha and ERbeta induced a dose-dependent reduction of contractility which was blocked by the ER inhibitor ICI 182,780. Moreover, the potential involvement of the novel membrane estrogen receptor GPR30 in mediating estrogen activity was determined using the selective GPR30 ligand G-1. Notably, specific inhibitors of ERK, PI3K, PKA, and eNOS transduction pathways abolished the cardiac responses to E(2). Taken together, our data suggest that ERalpha and ERbeta along with several signaling cascades are involved in the action of E(2) on the male rat heart. Our results also point to a potential role of GPR30, however further evaluation is required in order to fully understand the contribution of the different estrogen receptors in mediating estrogen activity on cardiac performance.
Subject(s)
Estradiol/pharmacology , Heart/drug effects , Receptors, G-Protein-Coupled/metabolism , Signal Transduction/drug effects , Animals , Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors , Dose-Response Relationship, Drug , Estrogen Receptor alpha/agonists , Estrogen Receptor alpha/antagonists & inhibitors , Estrogen Receptor alpha/genetics , Estrogen Receptor alpha/metabolism , Estrogen Receptor beta/agonists , Estrogen Receptor beta/antagonists & inhibitors , Estrogen Receptor beta/genetics , Estrogen Receptor beta/metabolism , Extracellular Signal-Regulated MAP Kinases/antagonists & inhibitors , Extracellular Signal-Regulated MAP Kinases/metabolism , GTP-Binding Protein alpha Subunits, Gi-Go/antagonists & inhibitors , Gene Expression , Heart Rate/drug effects , In Vitro Techniques , Male , Nitric Oxide Synthase Type III/antagonists & inhibitors , Nitric Oxide Synthase Type III/metabolism , Phosphoinositide-3 Kinase Inhibitors , RNA, Messenger/metabolism , Rats , Rats, Wistar , Receptors, G-Protein-Coupled/agonists , Receptors, G-Protein-Coupled/genetics , Ventricular Pressure/drug effectsABSTRACT
AIMS: Using a model of isolated and Langendorff-perfused rat heart we analysed whether activation of beta3-adrenergic receptors (beta3-ARs) influences ventricular lusitropic performance. We also focused on the NOS/NO/cGMP/PKG cascade as the signal transduction mechanism. METHODS: Hearts were treated with increasing concentrations (from 10(-12) to 10(-6) m) of BRL(37344), a selective beta3-AR agonist, and cardiac performance was evaluated by analysing both lusitropic parameters and coronary motility. Cardiac preparations were also perfused with BRL(37344) in the presence of either isoproterenol (ISO) or nadolol, or pertussis toxin (PTx), or selective inhibitors of the NOS/NO/cGMP/PKG pathway. RESULTS: BRL(37344) caused a significant concentration-dependent reduction in (LVdP/dt)(min), a decrease in half time relaxation significant starting from 10(-12) m, and an increase in (LVdP/dt)(max)/(LVdP/dt)(min) ratio (T/-t). BRL(37344) abolished the ISO-mediated positive lusitropism. beta3-AR-dependent effects on relaxation were insensitive to beta(1)/beta2-AR inhibition by nadolol (100 nm), and were abolished by G(i/o) protein inhibition by PTx (0.01 nm). NO scavenging by haemoglobin (10 microm), and nitric oxide synthase (NOS) inhibition by NG-monomethyl-l-arginine (10 microm) revealed the involvement of NO signalling in BRL(37344) response. Pre-treatment with inhibitors of either soluble guanylate cyclase (ODQ; 10 microm) or PKG (KT(5823); 100 nm) abolished beta3-AR-dependent negative lusitropism. In contrast, anantin (10 nm), an inhibitor of particulate guanylate cyclase, did not modify the effect of BRL(37344) on relaxation. CONCLUSION: Taken together, our findings provide functional evidence for beta3-AR modulation of ventricular relaxation in the rat heart which involves PTx-sensitive inhibitory Gi protein and occurs via an NO-cGMP-PKG cascade. Whether the effects of beta3-AR stimulation on lusitropism are beneficial or detrimental remains to be established.
Subject(s)
Cyclic GMP-Dependent Protein Kinases/physiology , Nitric Oxide/physiology , Receptors, Adrenergic, beta-3/physiology , Ventricular Function, Left/physiology , Adrenergic beta-Agonists/pharmacology , Adrenergic beta-Antagonists/pharmacology , Animals , Dose-Response Relationship, Drug , Ethanolamines/pharmacology , GTP-Binding Protein alpha Subunits, Gi-Go/physiology , Isoproterenol/antagonists & inhibitors , Isoproterenol/pharmacology , Male , Organ Culture Techniques , Rats , Rats, Wistar , Signal Transduction/physiology , Ventricular Function, Left/drug effectsABSTRACT
The intracellular messenger cyclic GMP (cGMP) represents the key signal in several transduction pathways throughout the animal world. In the heart cGMP signaling contributes to functional interaction of different cell types. Nitric oxide (NO) and natriuretic peptides (NPs), major autocrine-paracrine cardiovascular regulators, increment intracellular cGMP through guanylate cyclases (GCs). NO and NPs interact with two GC types: cytosolic (soluble: sGC) and membrane bound [particulate: pGC (NP receptor types A and B)], respectively. Depending on sub-cellular localization and regulation of the enzymes, cGMP produced by either pGC or sGC exerts different complementary effects. The two pathways are reciprocally regulated. NPs-depending pGC is modulated by NO-cGMP signaling, and the activity of NO is influenced by cellular concentrations of both NO itself and NPs. This heterologous feedback regulates GCs, linking cardiovascular autocrine-paracrine activities of NPs and NO. Importance of these cGMP converging routes goes far beyond their role under normal conditions. They are of relevance especially in disease states when tissue and circulating levels of NPs, and local NO production are altered. An example is the endothelial dysfunction associated with deficient NO production and uncoupled endothelium-myocardium communications. In this case, NPs-pGC-cGMP could supplement the reduced activity of NO-scGC-cGMP pathway. In addition, these systems regulate cell growth and apoptosis, playing a role in myocardial pathological morpho-functional remodeling. Here we will review recent concepts on NO/NPs dependent control of heart function in vertebrates, also focusing on cGMP-activated downstream signaling and its role in health and disease conditions.
Subject(s)
Cardiovascular Diseases/physiopathology , Cardiovascular System/metabolism , Cyclic GMP/biosynthesis , Animals , Cardiovascular Physiological Phenomena , Guanylate Cyclase/metabolism , Humans , Nitric Oxide/physiology , Nitric Oxide Synthase/physiologyABSTRACT
BACKGROUND: This study was designed to determine the debated prognostic significance of reverse transcriptase-polymerase chain reaction (RT-PCR) positivity in melanoma patients' sentinel lymph node (SLN) negative by conventional histopathology (PATH). PATIENTS AND METHODS: Patients with primary stage I-II cutaneous melanoma underwent radioguided sentinel lymphadenectomy. Their SLNs were assessed for tyrosinase (Tyr) and melanoma antigens recognized by T-cells (MART-1) mRNA expression using RT-PCR, in parallel with hematoxylin and eosin staining and immunohistochemistry. Tyr and MART-1 expression in the SLNs were correlated with PATH assay results, standard prognostic factors, time to progression and overall survival. RESULTS: Twenty-three of the 124 patients (18.5%) had positive SLNs by both PATH and RT-PCR (PATH+/PCR+). Sixteen patients (13%) were negative by PATH and positive by RT-PCR (PATH-/PCR+). Eighty-five patients (68.5%) had SLNs that were negative by both PATH and RT-PCR (PATH-/PCR-). At a median follow-up of 30 months, recurrence rates among the three cohorts were statistically different (PATH+/PCR+, 60%; PATH-/PCR+, 31%; PATH-/PCR-, 9.4%). Seven of 23 (30%) and two of 16 (12.5%) patients died in the PATH+/PCR+ and PATH-/PCR+ SLN groups, respectively, whereas no patient died in the PATH-/PCR- SLN group. CONCLUSIONS: RT-PCR is more sensitive than PATH to detect SLN metastases and it is a reliable predictor of disease relapse in stage I-II melanoma patients.
Subject(s)
Melanoma/pathology , Monophenol Monooxygenase/genetics , Neoplasm Proteins/genetics , Sentinel Lymph Node Biopsy , Skin Neoplasms/pathology , Adult , Aged , Aged, 80 and over , Antigens, Neoplasm , Cohort Studies , Disease Progression , Female , Follow-Up Studies , Head and Neck Neoplasms/drug therapy , Head and Neck Neoplasms/genetics , Head and Neck Neoplasms/pathology , Humans , Lymph Node Excision , MART-1 Antigen , Male , Melanoma/drug therapy , Melanoma/genetics , Middle Aged , Neoplasm Recurrence, Local/drug therapy , Neoplasm Recurrence, Local/genetics , Neoplasm Recurrence, Local/pathology , Neoplasm Staging , Prognosis , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Skin Neoplasms/drug therapy , Skin Neoplasms/genetics , Survival Rate , Time FactorsABSTRACT
The potent vasomodulator adenosine (AD), thanks to the interaction with by A(1) and A(2) receptors, dilates systemic, coronary and cerebral vasculatures but exert a constrictor action in several vessels of respiratory organs. Recent investigations suggest that nitric oxide (NO) contributes to AD effects. In fish, both NO and AD induce atypical effects compared to mammals. Since there is very little information on the role of NO and its involvement in mediating the actions of AD in fish, we have analysed this question in the branchial vasculature of the elasmobranch Squalus acanthias and the teleost Anguilla anguilla using an isolated perfused head and a branchial basket preparation, respectively. In both dogfish and eel, AD dose-response curves showed a biphasic effect: vasoconstriction (pico to nanomolar range) and vasodilation (micromolar range). Both effects were abolished by the classic xanthine inhibitor theophylline (Theo) and also by specific antagonists of A(1) and A(2) receptor subtypes. To analyse the involvement of the NO/cGMP system in the AD responses, we tested a NOS inhibitor, l-NIO, and a specific soluble guanylate cyclase (sGC) blocker, ODQ. In both dogfish and eel preparations l-NIO abrogated all vasomotor effects of AD, whereas ODQ blocked the AD-mediated vasoconstriction without affecting the vasorelaxant response. This indicates that only AD-induced vasoconstriction is mediated by a NO-cGMP-dependent mechanism. By using the NO donor SIN-1, we showed a dose-dependent vasoconstrictory effect which was completely blocked by ODQ. These results provide compelling evidence that the vasoactive role of AD in the branchial circulation of S. acanthias and A. anguilla involves a NO signalling.