Rho-kinase inhibition prevents proteinuria in immune-complex-mediated antipodocyte nephritis

2012 ◽  
Vol 303 (7) ◽  
pp. F1015-F1025 ◽  
Author(s):  
Catherine Meyer-Schwesinger ◽  
Silke Dehde ◽  
Marlies Sachs ◽  
Sabrina Mathey ◽  
Kazem Arefi ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Immune Complex ◽  
Kinase Activity ◽  
Periodic Acid ◽  
Rho Kinase ◽  
Kinase Inhibition ◽  
Filtration Barrier ◽  
Foot Process ◽  
Rho Kinases ◽  
Process Retraction

Podocyte foot process retraction is a hallmark of proteinuric glomerulonephritis. Cytoskeletal rearrangement causes a redistribution of slit membrane proteins from the glomerular filtration barrier towards the cell body. However, the underlying signaling mechanisms are presently unknown. Recently, we have developed a new experimental model of immune-mediated podocyte injury in mice, the antipodocyte nephritis (APN). Podocytes were targeted with a polyclonal antipodocyte antibody causing massive proteinuria around day 10. Rho-kinases play a central role in the organization of the actin cytoskeleton of podocytes. We therefore investigated whether inhibition of Rho-kinases would prevent podocyte disruption. C57/BL6 mice received antipodocyte serum with or without daily treatment with the specific Rho-kinase inhibitor HA-1077 (5 mg/kg). Immunoblot analysis demonstrated activation of Rho-kinase in glomeruli of antipodocyte serum-treated mice, which was prevented by HA-1077. Increased Rho-kinase activity was localized to podocytes in APN mice by immunostainings against the phosphorylated forms of Rho-kinase substrates. Rho-kinase inhibition significantly reduced podocyte loss from the glomerular tuft. Periodic acid staining demonstrated less podocyte hypertrophy in Rho-kinase-inhibited APN mice, despite similar amounts of immune complex deposition. Electron microscopy revealed reduced foot process effacement compared with untreated APN mice. Internalization of the podocyte slit membrane proteins nephrin and synaptopodin was prevented by Rho-kinase inhibition. Functionally, Rho-kinase inhibition significantly reduced proteinuria without influencing blood pressure. In rats with passive Heymann nephritis and human kidney biopsies from patients with membranous nephropathy, Rho-kinase was activated in podocytes. Together, these data suggest that increased Rho-kinase activity in the podocyte may be a mechanism for in vivo podocyte foot process retraction.

scholarly journals Localization of the membrane attack complex (MAC) in experimental immune complex glomerulonephritis.

1983 ◽  
Vol 157 (6) ◽  
pp. 1885-1905 ◽  
Author(s):  
D Koffler ◽  
G Biesecker ◽  
B Noble ◽  
G A Andres ◽  
A Martinez-Hernandez
Keyword(s):  
Basement Membrane ◽  
Immune Complex ◽  
Immune Complexes ◽  
Tissue Injury ◽  
Membrane Attack Complex ◽  
Intense Staining ◽  
Immune Complex Glomerulonephritis ◽  
Filtration Barrier ◽  
Dense Deposits ◽  
Foot Process

The role of the membrane attack complex (MAC) as a mediator of renal tissue injury was evaluated in rats affected by bovine serum albumin (BSA)-induced immune complex glomerulonephritis. Immunofluorescence studies revealed concurrent deposits of IgG, BSA, C3, and the MAC along glomerular capillary walls, although the MAC manifested a more restricted distribution than that observed for immune complexes. Immunoelectron microscopic techniques were utilized to demonstrate immune complexes, C3, and the MAC within dense deposits in the subepithelial aspect of the basement membrane. Visceral epithelial foot processes were fused in areas overlying large dense deposits and exhibited intense staining for the MAC, lesser reactivity for C3 but IgG was absent from the foot process membranes. Smaller granular deposits of immune complexes, C3, and the MAC were observed in the subendothelial region of the lamina rara interna and the lamina densa. Immune complexes may activate the classical complement pathway causing diffuse injury to the glomerular basement membrane (GBM), allowing subepithelial accumulation of complexes. These observations implicate the MAC as a mediator of GBM and juxtaposed podocyte membrane injury, thereby contributing to disruption of the glomerular filtration barrier. IgG and C3 were demonstrated within tubulointerstitial regions on the surface of collagen fibers in close proximity to the tubular basement membrane (TBM) of proximal convoluted tubules. Within the TBM, C3 localization was prominent with diminished reactivity for the MAC, but IgG was not detectable. The demonstration of C3 and scant MAC deposits in the TBM of nonimmunized control rats without evidence of interstitial IgG and C3 deposits suggests that both nonimmune and immune processes play a role in the pathogenesis of extraglomerular lesions. Evidence derived from these morphologic studies indicates that the MAC is associated with injury to the GBM, foot process membranes of visceral epithelium, and the TBM. Further experiments designed to selectively enhance or inhibit the deposition of MAC and assess consequent renal dysfunction are required to substantiate hypotheses concerning the in vivo membranolytic potential of the MAC in experimental immune complex glomerulonephritis.

scholarly journals Rho-kinase inhibition alleviates pulmonary hypertension in transgenic mice expressing a dominant-negative type II bone morphogenetic protein receptor gene

2011 ◽  
Vol 301 (5) ◽  
pp. L667-L674 ◽  
Author(s):  
Tadashi Yasuda ◽  
Yuji Tada ◽  
Nobuhiro Tanabe ◽  
Koichiro Tatsumi ◽  
James West
Keyword(s):  
Pulmonary Hypertension ◽  
Kinase Activity ◽  
Pulmonary Arteries ◽  
Rho Kinase ◽  
Dominant Negative ◽  
Type Ii ◽  
Kinase Inhibition ◽  
Bone Morphogenetic Protein Receptor ◽  
Protein Receptor ◽  
Morphogenetic Protein

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by a sustained elevation in the pulmonary artery pressure and subsequent right heart failure. The activation of Rho/Rho-kinase activity and the beneficial effect of Rho-kinase inhibition have been demonstrated in several experimental models of pulmonary hypertension. However, it remains unclear whether Rho-kinase inhibitors can also be used against pulmonary hypertension associated with mutations in the type II bone morphogenetic protein receptor (BMPRII) gene. Transgenic mice expressing a dominant-negative BMPRII gene (with an arginine to termination mutation at amino acid 899) in smooth muscle by a tetracycline-gene switch system (SM22-tet-BMPR2R899X mice) were examined. They developed an elevated right ventricular systolic pressure (RVSP), right ventricular (RV) hypertrophy, muscularization of small pulmonary arteries, and an associated disturbed blood flow in their lungs. The Rho/Rho-kinase activity and Smad activity were determined by a Western blot analysis by detecting GTP-RhoA and the phosphorylation of myosin phosphatase target subunit 1, Smad1, and Smad2. In the lungs of SM22-tet-BMPR2R899X mice, the Rho/Rho-kinase activity was elevated significantly, whereas the Smad activity was almost unchanged. Fasudil, a Rho-kinase inhibitor, significantly decreased RVSP, alleviated RV hypertrophy and muscularization of small pulmonary arteries, and improved blood flow in SM22-tet-BMPR2R899X mice, although it did not alter Smad signaling. Our study demonstrates that Rho/Rho-kinase signaling is activated via a Smad-independent pathway in an animal model of pulmonary hypertension with a BMPRII mutation in the cytoplasmic tail domain. Rho-kinase inhibition is therefore a possible therapeutic approach for the treatment of PAH associated with genetic mutation.

Phosphatidylinositol 3-kinase inhibition induces vasodilator effect of sevoflurane via reduction of Rho kinase activity

Life Sciences ◽  
2017 ◽  
Vol 177 ◽  
pp. 20-26 ◽  
Author(s):  
Yasunori Miyamoto ◽  
Guo-Gang Feng ◽  
Shiho Satomi ◽  
Katsuya Tanaka ◽  
Yoshihiro Fujiwara ◽  
...  
Keyword(s):  
Kinase Activity ◽  
Rho Kinase ◽  
Phosphatidylinositol 3 Kinase ◽  
Kinase Inhibition ◽  
Vasodilator Effect ◽  
Phosphatidylinositol 3

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.

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.

scholarly journals The Neuroprotective Potential of Rho-Kinase Inhibition in Promoting Cell Survival and Reducing Reactive Gliosis in Response to Hypoxia in Isolated Bovine Retina

2013 ◽  
Vol 32 (1) ◽  
pp. 218-234 ◽  
Author(s):  
Aizhan Alt ◽  
Ralf-Dieter Hilgers ◽  
Aysegül Tura ◽  
Khaled Nassar ◽  
Toni Schneider ◽  
...  
Keyword(s):  
Cell Survival ◽  
Rho Kinase ◽  
Reactive Gliosis ◽  
Kinase Inhibition ◽  
Bovine Retina

The effect of Rho Kinase inhibition on corneal nerve regeneration in vitro and in vivo

2021 ◽  
Author(s):  
Sonja Mertsch ◽  
Inga Neumann ◽  
Cosima Rose ◽  
Marc Schargus ◽  
Gerd Geerling ◽  
...  
Keyword(s):  
Nerve Regeneration ◽  
Rho Kinase ◽  
Kinase Inhibition ◽  
Corneal Nerve ◽  
Regeneration In Vitro

scholarly journals The atypical structure and function of newborn arterial endothelium is mediated by Rho/Rho kinase signaling

2014 ◽  
Vol 307 (4) ◽  
pp. H628-H632 ◽  
Author(s):  
Sheila Flavahan ◽  
Nicholas A. Flavahan
Keyword(s):  
Laser Scanning ◽  
Rho Kinase ◽  
Laser Scanning Microscopy ◽  
Scanning Microscopy ◽  
Stress Fibers ◽  
Light Chains ◽  
Myosin Light Chains ◽  
Kinase Signaling ◽  
No Donor ◽  
Kinase Inhibition

Endothelium of fetal or newborn arteries is atypical, displaying actin stress fibers and reduced nitric oxide (NO)-mediated dilatation. This study tested the hypothesis that Rho/Rho kinase signaling, which promotes endothelial stress fibers and inhibits endothelial dilatation, contributed to this phenotype. Carotid arteries were isolated from newborn [ postnatal day 1 (P1)], P7, and P21 mice. Endothelial dilatation to acetylcholine (pressure myograph) was minimal at P1, increased at P7, and further increased at P21. Inhibition of Rho (C3 transferase) or Rho kinase (Y27632, fasudil) significantly increased dilatation to acetylcholine in P1 arteries but had no effect in P7 or P21 arteries. After inhibition of NO synthase ( NG-nitro-l-arginine methyl ester), Rho kinase inhibition no longer increased acetylcholine responses in P1 arteries. Rho kinase inhibition did not affect dilatation to the NO donor DEA-NONOate. The endothelial actin cytoskeleton was labeled with phalloidin and visualized by laser-scanning microscopy. In P1 arteries, the endothelium had prominent transcytoplasmic stress fibers, whereas in P7 and P21 arteries, the actin fibers had a significantly reduced intensity and were restricted to cell borders. Phosphorylation of myosin light chains, a Rho kinase substrate, was highest in P1 endothelium and significantly reduced in P7 and P21 endothelium (laser-scanning microscopy). In P1 arteries, inhibition of Rho (C3 transferase) or Rho kinase (Y27632) significantly reduced the intensity of actin fibers, which were restricted to cell borders. Similarly, in P1 arteries, Rho inhibition significantly reduced endothelial levels of phosphorylated myosin light chains. These results indicate that the atypical function and morphology of newborn endothelium is mediated by Rho/Rho kinase signaling.

Induction of the Stem-like Cell Regulator CD44 by Rho Kinase Inhibition Contributes to the Maintenance of Colon Cancer–Initiating Cells

2012 ◽  
Vol 72 (19) ◽  
pp. 5101-5110 ◽  
Author(s):  
Hirokazu Ohata ◽  
Tatsuya Ishiguro ◽  
Yuki Aihara ◽  
Ai Sato ◽  
Hiroaki Sakai ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Rho Kinase ◽  
Kinase Inhibition
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