The way cancer cells escape cisplatin-induced apoptosis has not been completely elucidated yet. We questioned the relevance of "metabolic reprogramming" in cisplatin-resistance by studying mitochondrial function and metabolism in human ovarian carcinoma cell lines, both cisplatin-sensitive (2008) and resistant (C13). C13 cells, in comparison to 2008 cells, showed lower apoptotic response to cisplatin exposure, lower basal oxygen consumption (4.2±0.2 vs 6.5±0.7 fmol/cell/min, p<0.005) and a lower basal transmembrane mitochondrial potential (Δψm) (18.7±1.5 vs 32.2±1 MFI p<0.001). Moreover, C13 cells showed a lower sensitivity to rotenone and oligomycin, two mitochondrial respiratory chain inhibitors. To further investigate the impact of mitochondria on cisplatin-resistance, 2008 and C13 cells were depleted of their mitochondrial DNA (rho(0)-clones). The cytotoxicity of cisplatin was lower in 2008-rho(0)clones than in 2008 cells (IC(50) of 3.56 µM and 0.72 µM, respectively) but similar between C13-rho(0) and C13 cells (IC(50) of 5.49 µM and 6.49 µM, respectively). The time-course of cell viability in glucose-free galactose medium indicated that C13 cells are more strictly dependent on glucose than 2008 cells. (1)H-NMR spectroscopy showed a higher basal content of intracellular glutathione (GSH) and mobile lipids (MLs) in C13 cells as compared to 2008 cells, with higher lipid accumulation mainly within cytoplasmic droplets of the C13 cells. These findings allow us to propose a "metabolic remodelling" of ovarian carcinoma cells to a lipogenic phenotype, which includes alteration of mitochondrial function, as an advantageous mechanism to escape cisplatin-induced apoptosis. This hypothesis is of interest to exploit new pharmacological targets to improve the clinical impact of platinum drugs.
A B S T R A C T The cellularity of normal and lipomatous adipose tissue and its response to different lipolytic agents have been studied in a group of 10 patients with multiple symmetric lipomatosis (MSL).In MSL patients, fat cells from lipomatous tissue are smaller than normal, uninvolved adipocytes. Fat cells from lipomata show minimal variations in size following conspicuous increase of lipomatous masses. These findings suggest that the growth of lipomata can be attributed to the neoformation of adipocytes rather than to an enlargement in the single fat cells.The incidence of reduced glucose tolerance and of hyperlipoproteinemia is similar in MSL patients and in controls. A significant reduction in plasma free fatty acids was observed in MSL patients after a 24-h fast as well as after noradrenaline infusion.A specific insensitivity of lipomatous tissue to the lipolytic effect of noradrenaline and isoprenaline was observed in vitro, as indicated by glycerol release in the medium, whereas response to theophylline and to dibutyryl cyclic AMP was retained. The lipolytic response to catecholamines was normal in the nonlipomatous adipose tissue of MSL patients. In basal conditions ATP concentrations were similar in normal and in lipomatous adipose tissue. However, incubation with noradrenaline induced a significant fall in intracellular ATP levels in normal tissue, whereas no variations were observed in lipomatous tissue. Theophylline, instead, induced a prompt and significant decrease in intracellular ATP levels in lipomatous tissue. These obervations indicate that the block in catecholPreliminary results of in vitro studies were presented at
Several risk factors are associated with a worse outcome for COVID-19 patients; the most recognized are demographic characteristics such as older age and male gender, and pre-existing cardiovascular conditions. About the latter, hypertension and coronary heart disease are among the most common comorbidities recorded in infected patients, together with type 2 diabetes mellitus (T2DM). Data from Istituto Superiore di Sanità (ISS, Italy) show that more than 68.3% of patients had hypertension, 28.2% ischemic heart disease, 22.5% atrial fibrillation, while 30.1% T2DM. Several authors suggested that cardiovascular diseases and diabetes mellitus are linked to endothelial dysfunction, and all of them are strictly related to aging.Considering the impact of the gender on the COVID-19 epidemic, even if confirmed cases from each nation are changing every day, epidemiological data clearly evidence that in men the infection causes worse outcomes compared to women. In Italy, up to 21 May, in the age range of 60-89 years, male deaths were 63.9% of total cases. The reason behind this difference between genders appears not clear; however, the diversity in sex-hormones and styles of life are believed to play a role in the patient's susceptibility to severe SARS-CoV-2 outcomes. It is known that the activation of endothelial estrogen receptors increases NO and decreases ROS, protecting the vascular system from angiotensin II-mediated vasoconstriction, inflammation, and ROS production.During the pandemic, joining forces is vital; thus, as people help doctors by limiting their displacements out of their houses avoiding hence the spread of the infection, doctors help patients to overcome severe SARS-CoV-2 infections by using multiple pharmacological approaches. In this context, the preservation of endothelial function and the mitigation of vascular inflammation are prominent targets, essential to reduce severe outcomes also in male older patients.
The cardiac activity of a series of milrinone analogues, 2-substituted 3-acyl-1,6-dihydro-6-oxo-5-pyridinecarbonitriles, 1,6,3,2,11,12-hexahydro-6,3-dioxo-5-quinolinecarbonitriles, the correlated carboxylic acids, 2-substituted 3-acyl-6(1H)-pyridones, and 7,8-dihydro-2,5(1H,6H)-quinolinediones, was evaluated in spontaneously beating and in electrically driven atria from reserpine-treated guinea pigs. Their effects were compared with those induced by amrinone and milrinone in both the atria preparations. Compounds SF28 (3-acetyl-1,6-dihydro-2-methyl-6-oxo-5-pyridinecarbonitrile) and SF40 (7,8-dihydro-7-methyl-2,5(1H,6H)-quinolinedione) were the most effective positive inotropic agents. An inhibition of the negative influence exerted by endogenous adenosine on heart preparations seems to be involved in their contractile activity. SF38 (3-benzoyl-2-phenyl-6(1H)-pyridinone), on the contrary, reduced the contractile force and the frequency rate of guinea pig atria with a mechanism not related to an activation of cholinergic or purinergic inhibitory receptors on the heart. X-ray analysis carried out on the three model compounds, SF28, SF40 (positive inotropic agents), and SF38 (negative inotropic agent), and molecular modeling evidenced that the change from phenyl (SF38) to methyl (SF28) or the introduction of a side cyclic aliphatic chain (SF40) results in a variation of conformational preference and topography which may address the different molecules toward distinct receptor pockets according to the resulting inotropic effect.
1 Purine compounds such as ATP and adenosine, respectively endothelium-dependent and -independent vasodilators, are largely involved in the control of vascular tone and vascular reactivity to contracting stimuli. We investigated the relaxing activity of ATP and adenosine in guinea-pig aorta rings exposed for 6 h to elevated glucose concentration (50 mM), in order to mimic hyperglycaemic conditions. Guinea-pigs were reserpine-treated (2 mg kg 71 , i.p., 48 and 24 h before death). 2 Rings of aortae incubated in 50 mM glucose, contracted submaximally by 1 mM noradrenaline, lost endothelium-dependent relaxation in response to acetylcholine (10 nM to 10 mM). Aortae incubated with 50 mM mannose, as a hyperosmotic control, relaxed to acetylcholine normally. Rings of aortae incubated in 50 mM glucose, contracted submaximally by 3 mM 4-aminopyridine, lost endothelium-dependent relaxation in response to ATP (30 mM) whereas endothelium-independent relaxation in response to adenosine (0.3 mM) was well preserved. 4 The relaxation induced by A23187 or sodium nitroprusside (10 nM to 0.1 mM) did not di er between rings exposed to control (5.5 mM) or elevated glucose (50 mM) and contracted submaximally by 3 mM 4-aminopyridine. 5 When incubated with aortic tissue in the presence of elevated glucose, the cyclo-oxygenase inhibitors, indomethacin (10 mM) and mefenamic acid (30 mM), or the scavenger of superoxide anions, superoxide dismutase (150 u ml 71 ), prevented the impairment of ATP-mediated relaxation. 6 The present results indicate that endothelium-dependent, receptor-induced relaxation in response to acetylcholine and ATP is impaired in guinea-pig aorta rings exposed to elevated glucose. The endothelial dysfunction caused by glucose might be located at a step between receptor activation and intracellular calcium increase, and might be related to an increased metabolism of arachidonic acid coupled to an increased production, or to a reduced inactivation of superoxide anions.
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