491 Down-Regulation of MicroRNA-133a Due to Oxidative Stress Mediates Up-Regulation of RHOA Expression and Increase in Rho Kinase Activity and Gastric Muscle Contraction in Diabetes

2012 ◽  
Vol 142 (5) ◽  
pp. S-105 ◽  
Author(s):  
Sunila Mahavadi ◽  
Wimolpak Sriwai ◽  
Divya P. Kumar ◽  
Ruizhe Zhou ◽  
John R. Grider ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Muscle Contraction ◽  
Kinase Activity ◽  
Rho Kinase ◽  
Down Regulation ◽  
Gastric Muscle

scholarly journals Activation of G protein-coupled bile acid receptor, TGR5, induces smooth muscle relaxation via both Epac- and PKA-mediated inhibition of RhoA/Rho kinase pathway

2013 ◽  
Vol 304 (5) ◽  
pp. G527-G535 ◽  
Author(s):  
Senthilkumar Rajagopal ◽  
Divya P. Kumar ◽  
Sunila Mahavadi ◽  
Sayak Bhattacharya ◽  
Ruizhe Zhou ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Kinase Activity ◽  
Muscle Relaxation ◽  
Rho Kinase ◽  
Muscle Cells ◽  
Receptor Activation ◽  
Gastric Smooth Muscle ◽  
Selective Ligand ◽  
Gastric Muscle ◽  
Kinase Pathway

The present study characterized the TGR5 expression and the signaling pathways coupled to this receptor that mediates the relaxation of gastric smooth muscle. TGR5 was detected in gastric muscle cells by RT-PCR and Western blotting. Treatment of cells with the TGR5-selective ligand oleanolic acid (OA) activated Gαs, but not Gαq, Gαi1, Gαi2, or Gαi3, and increased cAMP levels. OA did not elicit contraction, but caused relaxation of carbachol-induced contraction of gastric muscle cells from wild-type mice, but not tgr5−/− mice. OA, but not a selective exchange protein activated by cAMP (Epac) ligand (8-pCPT-2′-O-Me-cAMP), caused phosphorylation of RhoA and the phosphorylation was blocked by the PKA inhibitor, myristoylated PKI, and by the expression of phosphorylation-deficient mutant RhoA (S188A). Both OA and Epac ligand stimulated Ras-related protein 1 (Rap1) and inhibited carbachol (CCh)-induced Rho kinase activity. Expression of RhoA (S188A) or PKI partly reversed the inhibition of Rho kinase activity by OA but had no effect on inhibition by Epac ligand. However, suppression of Rap1 with siRNA blocked the inhibition of Rho kinase by Epac ligand, and partly reversed the inhibition by OA; the residual inhibition was blocked by PKI. Muscle relaxation in response to OA, but not Epac ligand, was partly reversed by PKI. We conclude that activation of TGR5 causes relaxation of gastric smooth muscle and the relaxation is mediated through inhibition of RhoA/Rho kinase pathway via both cAMP/Epac-dependent stimulation of Rap1 and cAMP/PKA-dependent phosphorylation of RhoA at Ser188. TGR5 receptor activation on smooth muscle reveals a novel mechanism for the regulation of gut motility by bile acids.

scholarly journals Effects of Tolvaptan on Oxidative Stress in ADPKD: A Molecular Biological Approach

2022 ◽  
Vol 11 (2) ◽  
pp. 402
Author(s):  
Matteo Rigato ◽  
Gianni Carraro ◽  
Irene Cirella ◽  
Silvia Dian ◽  
Valentina Di Di Vico ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Protein Expression ◽  
Molecular Mechanisms ◽  
Kinase Activity ◽  
Rho Kinase ◽  
Renal Deterioration ◽  
Deterioration Rate ◽  
Function Loss ◽  
State Marker ◽  
Molecular Biological Approach

Autosomal dominant polycystic disease (ADPKD) is the most frequent monogenic kidney disease. It causes progressive renal failure, endothelial dysfunction, and hypertension, all of which are strictly linked to oxidative stress (OxSt). Treatment with tolvaptan is known to slow the renal deterioration rate, but not all the molecular mechanisms involved in this effect are well-established. We evaluated the OxSt state in untreated ADPKD patients compared to that in tolvaptan-treated ADPKD patients and healthy subjects. OxSt was assessed in nine patients for each group in terms of mononuclear cell p22phox protein expression, NADPH oxidase key subunit, MYPT-1 phosphorylation state, marker of Rho kinase activity (Western blot) and heme oxygenase (HO)-1, induced and protective against OxSt (ELISA). p22phox protein expression was higher in untreated ADPKD patients compared to treated patients and controls: 1.42 ± 0.11 vs. 0.86 ± 0.15 d.u., p = 0.015, vs. 0.53 ± 0.11 d.u., p < 0.001, respectively. The same was observed for phosphorylated MYPT-1: 0.96 ± 0.28 vs. 0.68 ± 0.09 d.u., p = 0.013 and vs. 0.47 ± 0.13 d.u., p < 0.001, respectively, while the HO-1 expression of untreated patients was significantly lower compared to that of treated patients and controls: 5.33 ± 3.34 vs. 2.08 ± 0.79 ng/mL, p = 0.012, vs. 1.97 ± 1.22 ng/mL, p = 0.012, respectively. Tolvaptan-treated ADPKD patients have reduced OxSt levels compared to untreated patients. This effect may contribute to the slowing of renal function loss observed with tolvaptan treatment.

Effect of oxidative stress on Rho kinase II and smooth muscle contraction in rat stomach

2015 ◽  
Vol 93 (6) ◽  
pp. 405-411 ◽  
Author(s):  
Othman Al-Shboul ◽  
Ayman Mustafa
Keyword(s):  
Oxidative Stress ◽  
Smooth Muscle ◽  
Muscle Contraction ◽  
Muscle Cell ◽  
Rho Kinase ◽  
Smooth Muscle Contraction ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rat Stomach ◽  
Cell Contraction ◽  
Kinase Pathway

Recent studies have shown that both Rho kinase signaling and oxidative stress are involved in the pathogenesis of a number of human diseases, such as diabetes mellitus, hypertension, and atherosclerosis. However, very little is known about the effect of oxidative stress on the gastrointestinal (GI) smooth muscle Rho kinase pathway. The aim of the current study was to investigate the effect of oxidative stress on Rho kinase II and muscle contraction in rat stomach. The peroxynitrite donor 3-morpholinosydnonimine (SIN-1), hydrogen peroxide (H2O2), and peroxynitrite were used to induce oxidative stress. Rho kinase II expression and ACh-induced activity were measured in control and oxidant-treated cells via specifically designed enzyme-linked immunosorbent assay (ELISA) and activity assay kits, respectively. Single smooth muscle cell contraction was measured via scanning micrometry in the presence or absence of the Rho kinase blocker, Y-27632 dihydrochloride. All oxidant agents significantly increased ACh-induced Rho kinase II activity without affecting its expression level. Most important, oxidative stress induced by all three agents augmented ACh-stimulated muscle cell contraction, which was significantly inhibited by Y-27632. In conclusion, oxidative stress activates Rho kinase II and enhances contraction in rat gastric muscle, suggesting an important role in GI motility disorders associated with oxidative stress.

scholarly journals Differential regulation of muscarinic M2 and M3 receptor signaling in gastrointestinal smooth muscle by caveolin-1

2013 ◽  
Vol 305 (3) ◽  
pp. C334-C347 ◽  
Author(s):  
Sayak Bhattacharya ◽  
Sunila Mahavadi ◽  
Othman Al-Shboul ◽  
Senthilkumar Rajagopal ◽  
John R. Grider ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Kinase Activity ◽  
Rho Kinase ◽  
Receptor Signaling ◽  
Caveolin 1 ◽  
Pi Hydrolysis ◽  
G Protein Coupled ◽  
Stimulation Of

Caveolae act as scaffolding proteins for several G protein-coupled receptor signaling molecules to regulate their activity. Caveolin-1, the predominant isoform in smooth muscle, drives the formation of caveolae. The precise role of caveolin-1 and caveolae as scaffolds for G protein-coupled receptor signaling and contraction in gastrointestinal muscle is unclear. Thus the aim of this study was to examine the role of caveolin-1 in the regulation of Gq- and Gi-coupled receptor signaling. RT-PCR, Western blot, and radioligand-binding studies demonstrated the selective expression of M2 and M3 receptors in gastric smooth muscle cells. Carbachol (CCh) stimulated phosphatidylinositol (PI) hydrolysis, Rho kinase and zipper-interacting protein (ZIP) kinase activity, induced myosin phosphatase 1 (MYPT1) phosphorylation (at Thr696) and 20-kDa myosin light chain (MLC20) phosphorylation (at Ser19) and muscle contraction, and inhibited cAMP formation. Stimulation of PI hydrolysis, Rho kinase, and ZIP kinase activity, phosphorylation of MYPT1 and MLC20, and muscle contraction in response to CCh were attenuated by methyl β-cyclodextrin (MβCD) or caveolin-1 small interfering RNA (siRNA). Similar inhibition of PI hydrolysis, Rho kinase, and ZIP kinase activity and muscle contraction in response to CCh and gastric emptying in vivo was obtained in caveolin-1-knockout mice compared with wild-type mice. Agonist-induced internalization of M2, but not M3, receptors was blocked by MβCD or caveolin-1 siRNA. Stimulation of PI hydrolysis, Rho kinase, and ZIP kinase activities in response to other Gq-coupled receptor agonists such as histamine and substance P was also attenuated by MβCD or caveolin-1 siRNA. Taken together, these results suggest that caveolin-1 facilitates signaling by Gq-coupled receptors and contributes to enhanced smooth muscle function.

scholarly journals INCREASED RHO KINASE ACTIVITY AND OXIDATIVE STRESS LEVELS IN DIABETIC HYPERTENSIVE PATIENTS

2011 ◽  
Vol 57 (14) ◽  
pp. E566
Author(s):  
Luigi Gabrielli ◽  
Jorge Jalil ◽  
María P. Ocaranza ◽  
Ulises Novoa ◽  
Italo Mora ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Kinase Activity ◽  
Rho Kinase ◽  
Hypertensive Patients ◽  
Stress Levels ◽  
And Oxidative Stress

Effect of Early Normotension with Olmesartan on Rho-kinase Activity in Hypertensive Patients

2019 ◽  
Vol 18 (1) ◽  
pp. 87-91 ◽  
Author(s):  
Claudio Cantin ◽  
Jorge E. Jalil ◽  
Juan F. Bulnes ◽  
Ulises Novoa ◽  
Paul MacNab ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Kinase Activity ◽  
Clinical Evidence ◽  
Mononuclear Cells ◽  
Treatment Initiation ◽  
Rho Kinase ◽  
Angiotensin Ii Receptor ◽  
Peripheral Blood Mononuclear ◽  
Hypertensive Patients ◽  
Rock Activity

Background: Angiotensin II is a potent activator of the Rho-kinase (ROCK) pathway, through which it exerts some of its adverse vasoconstrictor effects. Clinical evidence on the effects of blocking the angiotensin II receptor 1 on ROCK activity in hypertensive patients is scarce. Objective: To demonstrate that ROCK activity in peripheral blood mononuclear cells (PMBCs) in patients with essential hypertension is reduced earlier than previously observed, along with blood pressure (BP) lowering on treatment with olmesartan. Methods: Prospective pilot open study; 17 hypertensive patients were treated with progressive olmesartan doses starting with 20 mg qd. BP was measured at 3, 6 and 9 weeks after treatment initiation. If treatment failed to normalize BP after 3 weeks, olmesartan dose was increased to 40 mg qd, and if still hypertensive after 6 weeks, 12.5 mg of hydrochlorothiazide qd was added. ROCK activity was measured at baseline and 9 weeks after treatment as myosin phosphatase target subunit 1 phosphorylation (MYPT1-p/T ratio) in PBMC. Results: Mean baseline BP was 162 ± 4.9/101 ± 2.4 mmHg. After 9 weeks of treatment, both systolic and diastolic BP were reduced by 41 and 22 mmHg, respectively (p<0.05). Mean pretreatment MYPT1- p/T ratio in PMBCs was significantly reduced by 80% after 9 weeks with olmesartan (p<0.01). Conclusion: Normotension achieved after 9 weeks in 82% of the patients treated with olmesartan was associated with a significant reduction of ROCK activity in PBMC.

Down regulation of DJ-1 enhances cell death by oxidative stress, ER stress, and proteasome inhibition

2003 ◽  
Vol 312 (4) ◽  
pp. 1342-1348 ◽  
Author(s):  
Takanori Yokota ◽  
Kanako Sugawara ◽  
Kaoru Ito ◽  
Ryosuke Takahashi ◽  
Hiroyoshi Ariga ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Er Stress ◽  
Proteasome Inhibition ◽  
Down Regulation

scholarly journals Pro-Nerve Growth Factor Induces Activation of RhoA Kinase and Neuronal Cell Death

2019 ◽  
Vol 9 (8) ◽  
pp. 204 ◽  
Author(s):  
Marina Sycheva ◽  
Jake Sustarich ◽  
Yuxian Zhang ◽  
Vaithinathan Selvaraju ◽  
Thangiah Geetha ◽  
...  
Keyword(s):  
Cell Death ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Kinase Activity ◽  
Kinase Inhibitor ◽  
Neuronal Cell Death ◽  
Rho Kinase ◽  
Neuronal Cell ◽  
Nerve Growth ◽  
Rhoa Kinase

We have previously shown that the expression of pro-nerve growth factor (proNGF) was significantly increased, nerve growth factor (NGF) level was decreased, and the expression of p75NTR was enhanced in Alzheimer’s disease (AD) hippocampal samples. NGF regulates cell survival and differentiation by binding TrkA and p75NTR receptors. ProNGF is the precursor form of NGF, binds to p75NTR, and induces cell apoptosis. The objective of this study is to determine whether the increased p75NTR expression in AD is due to the accumulation of proNGF and Rho kinase activation. PC12 cells were stimulated with either proNGF or NGF. Pull-down assay was carried out to determine the RhoA kinase activity. We found the expression of p75NTR was enhanced by proNGF compared to NGF. The proNGF stimulation also increased the RhoA kinase activity leading to apoptosis. The expression of active RhoA kinase was found to be increased in human AD hippocampus compared to control. The addition of RhoA kinase inhibitor Y27632 not only blocked the RhoA kinase activity but also reduced the expression of p75NTR receptor and inhibited the activation of JNK and MAPK induced by proNGF. This suggests that overexpression of proNGF in AD enhances p75NTR expression and activation of RhoA, leading to neuronal cell death.

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