piperidines and acetovanillone

Atrial fibrillation (AF) occurs in up to 11% of cancer patients treated with ibrutinib. The pathophysiology of ibrutinib promoted AF is complicated, as there are multiple interactions involved; the detailed molecular mechanisms underlying this are still unclear. Here, we aimed to determine the electrophysiological and molecular mechanisms of burst-pacing-induced AF in ibrutinib-treated mice. The results indicated differentially expressed proteins in ibrutinib-treated mice, identified through proteomic analysis, were found to play a role in oxidative stress-related pathways. Finally, treatment with an inhibitor of NADPH oxidase (NOX) prevented and reversed AF development in ibrutinib-treated mice. It was showed that the related protein expression of reactive oxygen species (ROS) in the ibrutinib group was significantly increased, including NOX2, NOX4, p22-phox, XO and TGF-β protein expression. It was interesting that ibrutinib group also significantly increased the expression of ox-CaMKII, p-CaMKII (Thr-286) and p-RyR2 (Ser2814), causing enhanced abnormal sarcoplasmic reticulum (SR) Ca

Topics: Acetophenones; Adenine; Animals; Atrial Fibrillation; Calcium; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Disease Models, Animal; Humans; Male; Mice; Myocytes, Cardiac; Piperidines; Protein Interaction Maps; Proteomics; Reactive Oxygen Species; Sarcoplasmic Reticulum; Signal Transduction

Accumulative indoxyl sulfate (IS) retained in chronic kidney disease (CKD) can potentiate vascular endothelial dysfunction, and herein, we aim at elucidating the underlying mechanisms from the perspective of possible association between reactive oxygen species (ROS) and RhoA/ROCK pathway. IS-treated nephrectomized rats are administered with antioxidants including NADPH oxidase inhibitor apocynin, SOD analog tempol, and mitochondrion-targeted SOD mimetic mito-TEMPO to scavenge ROS, or ROCK inhibitor fasudil to obstruct RhoA/ROCK pathway. First, we find in response to IS stimulation, antioxidants treatments suppress increased aortic ROCK activity and expression levels. Additionally, ROCK blockade prevent IS-induced increased NADPH oxidase expression (mainly p22phox and p47phox), mitochondrial and intracellular ROS (superoxide and hydrogen peroxide) generation, and decreased Cu/Zn-SOD expression in thoracic aortas. Apocynin, mito-TEMPO, and tempol also reverse these markers of oxidative stress. These results suggest that IS induces excessive ROS production and ROCK activation involving a circuitous relationship in which ROS activate ROCK and ROCK promotes ROS overproduction. Finally, ROS and ROCK depletion attenuate IS-induced decrease in nitric oxide (NO) production and eNOS expression levels, and alleviate impaired vasomotor responses including increased vasocontraction to phenylephrine and decreased vasorelaxation to acetylcholine, thereby preventing cardiovascular complications accompanied by CKD. Taken together, excessive ROS derived from NADPH oxidase and mitochondria coordinate with RhoA/ROCK activation in a form of positive reciprocal relationship to induce endothelial dysfunction through disturbing endothelium-dependent NO signaling upon IS stimulation in CKD status.

Topics: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; Acetophenones; Animals; Antioxidants; Cyclic N-Oxides; Endothelium, Vascular; Gene Expression Regulation; Humans; Indican; NADPH Oxidases; Nitric Oxide; Nitric Oxide Synthase Type III; Organophosphorus Compounds; Oxidative Stress; Piperidines; Rats; Reactive Oxygen Species; Renal Insufficiency, Chronic; rho GTP-Binding Proteins; rho-Associated Kinases; Signal Transduction; Spin Labels

Exposure to microgravity results in cardiovascular deconditioning, and cerebrovascular oxidative stress injury has been suggested to occur. To elucidate the mechanism for this condition, we investigated whether simulated microgravity induces mitochondrial dysfunction in rat arteries. Four-week hindlimb unweighting (HU) was used to simulate microgravity in rats. Mitochondrial reactive oxygen species (ROS), mitochondrial membrane potential (Δψm), mitochondrial permeability transition pore (mPTP) opening, mitochondrial respiratory control ratio (RCR), MnSOD/GPx activity and expression, and mitochondrial malondialdehyde (MDA) were examined in rat cerebral and mesenteric VSMCs. Compared with the control rats, mitochondrial ROS levels, mPTP opening, and MDA content increased significantly (P<0.001, P<0.01, and P<0.01, respectively), Δψm, RCR, MnSOD/GPx activity (P<0.001 for Δψm and RCR; P<0.05 for MnSOD; and P<0.001 for GPx activity) and protein abundance of mitochondrial MnSOD/GPx-1 decreased (P<0.001 for MnSOD and GPx-1) in HU rat cerebral but not mesenteric arteries. Chronic treatment with NADPH oxidase inhibitor apocynin and mitochondria-targeted antioxidant mitoTempol promoted recovery of mitochondrial function in HU rat cerebral arteries, but exerted no effects on HU rat mesenteric arteries. Therefore, simulated microgravity resulted in cerebrovascular mitochondrial dysfunction, and crosstalk between NADPH oxidase and mitochondria participated in the process.

Topics: Acetophenones; Animals; Cerebral Arteries; Glutathione Peroxidase; Hindlimb Suspension; Male; Membrane Potential, Mitochondrial; Mesenteric Arteries; Mitochondria; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; NADPH Oxidases; Organophosphorus Compounds; Piperidines; Rats; Reactive Oxygen Species; Superoxide Dismutase; Weightlessness Simulation

It is unknown if endothelin-A and -B receptors (ET(A)R and ET(B)R) activate the production of superoxide via NAD(P)H oxidase and subsequently stimulate the formation of cyclic adenine diphosphate ribose (cADPR) in afferent arterioles. Vessels were isolated from rat kidney and loaded with fura 2. Endothelin-1 (ET-1) rapidly increased cytosolic Ca(2+) concentration ([Ca(2+)](i)) by 303 nM. The superoxide dismutase mimetic tempol, the NAD(P)H oxidase inhibitor apocynin, and nicotinamide, an inhibitor of ADPR cyclase, diminished the response by approximately 60%. The ET(B)R agonist sarafotoxin 6c (S6c) increased peak [Ca(2+)](i) by 117 nM. Subsequent addition of ET-1 in the continued presence of S6c caused an additional [Ca(2+)](i) peak of 225 nM. Neither nicotinamide or 8-bromo- (8-Br) cADPR nor apocynin decreased the [Ca(2+)](i) response to S6c, but inhibited the subsequent [Ca(2+)](i) response to ET-1. The ET(B)R blockers BQ-788 and A-192621 prevented the S6c [Ca(2+)](i) peak and reduced the ET-1 response by more than one-half, suggesting an ET(B)R/ET(A)R interaction. In contrast, the ET(A)R blocker BQ-123 had no effect on the S6c [Ca(2+)](i) peak and obliterated the subsequent ET-1 response. ET-1 immediately stimulated superoxide formation (measured with TEMPO-9-AC, 68 arbitrary units) that was inhibited 95% by apocynin or diphenyl iodonium. S6c or IRL-1620 increased superoxide by 8% of that caused by subsequent ET-1 addition. We conclude that ET(A)R activation of afferent arterioles increases the formation of superoxide that accounts for approximately 60% of subsequent Ca(2+) signaling. ET(B)R activation appears to result in only minor increases in superoxide production. Nicotinamide and 8-Br-cADPR results suggest that ET-1 (and primarily ET(A)R) causes the activation of vascular smooth muscle cell-ADPR cyclase.

Topics: Acetophenones; ADP-ribosyl Cyclase; Animals; Arterioles; Biphenyl Compounds; Bradykinin; Calcium Signaling; Cyclic N-Oxides; Endothelial Cells; Endothelin B Receptor Antagonists; Endothelins; Enzyme Inhibitors; Kidney; Muscle, Smooth, Vascular; NADPH Oxidases; NG-Nitroarginine Methyl Ester; Niacinamide; Oligopeptides; Onium Compounds; Peptide Fragments; Piperidines; Pyrrolidines; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A; Receptor, Endothelin B; Renal Circulation; Spin Labels; Superoxides; Vasoconstrictor Agents; Viper Venoms

We have recently reported that adventitial fibroblasts are able to express endothelin-1 (ET-1) in response to angiotensin II (Ang II) stimulation. However, the mechanism by which this occurs in the adventitia remains unclear. As Ang II has been reported to increase oxidant production by NADPH oxidase, we examined the role of this complex in Ang II stimulated ET-1 expression in vascular adventitial fibroblasts.. Adventitial fibroblasts were isolated and cultured from mouse aorta. Cells were treated with Ang II (100 nmol/L) in the presence or absence of NADPH oxidase inhibitors, apocynin (100 micromol/L) and diphenyleneiodonium (10 micromol/L), superoxide scavengers, SOD (350 units/mL), tempol (100 micromol/L), tiron (100 micromol/L), and ET-receptor antagonists (10 microM), BQ123 (for ET(A)-) and BQ788 (for ET(B)-). PreproET-1 mRNA and ET-1 level were determined by relative RT-PCR and ELISA, respectively. Type I procollagen-alpha-I (collagen) level was detected by Western blot. Superoxide anion (superoxide) production was determined by coelenterazine or lucigenin chemiluminescence. Ang II-induced collagen expression was inhibited by BQ123, suggesting that adventitial ET-1 plays a significant role in regulating the extracellular matrix. NADPH oxidase inhibitors and superoxide scavengers significantly decreased Ang II-induced ET-1 mRNA and peptide expression, superoxide production as well as collagen expression. Furthermore, deletion of gp91(phox) (a key subunit of NADPH oxidase) and overexpression of SOD1 attenuated Ang II-induced responses.. Ang II-evoked expression of ET-1 in adventitial fibroblasts appears to be mediated, at least in part, by NADPH oxidase. Functionally, this mechanism stimulates collagen expression thereby implicating the adventitia as a potential contributor to the vascular pathophysiology associated with oxidative stress and vascular remodeling.

Topics: 1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt; Acetophenones; Adenoviridae; Angiotensin II; Animals; Antioxidants; Aorta; Biomarkers; Catecholamines; Cells, Cultured; Collagen Type I; Collagen Type I, alpha 1 Chain; Connective Tissue; Cyclic N-Oxides; Dopamine Agonists; Endothelin A Receptor Antagonists; Endothelin B Receptor Antagonists; Endothelin-1; Fibroblasts; Gene Expression; Genetic Vectors; Image Processing, Computer-Assisted; Imidazolines; Male; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Mice, Knockout; Muscle, Smooth, Vascular; NADPH Oxidase 2; NADPH Oxidases; Oligopeptides; Peptides, Cyclic; Piperidines; Protein Precursors; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Spin Labels; Superoxide Dismutase; Transduction, Genetic

Leptin, the obese gene product, plays an important role in the regulation of cardiac function. However, the mechanism behind leptin-induced cardiomyocyte contractile response is poorly understood. This study was designed to examine whether endothelin-1 receptor and NADPH oxidase play any role in leptin-induced cardiac contractile response. Isolated murine cardiomyocytes were exposed to leptin (5, 50, and 100 nmol/L) for 60 minutes in the absence or presence of the ETA receptor antagonist BQ123 (1 micromol/L), the ETB receptor antagonist BQ788 (1 micromol/L), or the NADPH oxidase inhibitor apocynin (100 micromol/L) before mechanical function was studied. Superoxide levels were measured by dihydroethidium fluorescent dye and the superoxide dismutase-inhibitable reduction of cytochrome c. NADPH oxidase subunit expression (p22phox, p47phox, p67phox, and gp91phox) was evaluated with Western blot. Leptin depressed peak shortening and maximal velocity of shortening/relengthening (+/-dL/dt), prolonged the duration of relengthening (TR90) without affecting the time-to-peak cell shortening. Consistent with the mechanical characteristics, myocytes treated with leptin displayed a reduced electrically stimulated rise in intracellular Ca2+ (change in fura-2 fluorescence intensity) associated with a prolonged intracellular Ca2+ decay rate. All of the abnormalities were significantly attenuated by apocynin, BQ123, or BQ788. Intracellular superoxide generation was enhanced after leptin treatment, which was partially blocked by apocynin, BQ123, or BQ788. Leptin had no effect on p22phox and gp91phox but upregulated protein expression of p67phox and p47phox, both of which were inhibited by apocynin, BQ123, or BQ788. These results suggest that leptin suppresses cardiac contractile function in ventricular myocytes through the endothelin-1 receptor and NADPH oxidase-mediated pathway.

Topics: Acetophenones; Animals; Calcium; Cyclic N-Oxides; Endothelin A Receptor Antagonists; Enzyme Inhibitors; Heart Ventricles; Intracellular Membranes; Leptin; Male; Mice; Mice, Inbred C57BL; Myocardial Contraction; Myocytes, Cardiac; NADPH Oxidases; Oligopeptides; Peptides, Cyclic; Piperidines; Receptor, Endothelin A; Receptors, Leptin; Spin Labels; Superoxides