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1.
Am J Physiol Renal Physiol ; 317(4): F839-F851, 2019 10 01.
Article in English | MEDLINE | ID: mdl-31364374

ABSTRACT

The small GTPase Rho and its effector Rho kinase (ROCK) are involved in the pathogenesis of diabetic kidney disease. Rho kinase has two isoforms: ROCK1 and ROCK2. However, it remains unclear which is mainly involved in the progression of diabetic glomerulosclerosis and the regulation of profibrotic mediators. Glomeruli isolated from type 2 diabetic db/db mice demonstrated increased gene expression of transforming growth factor (TGF)-ß and its downstream profibrotic mediators. Chemical inhibition of ROCK suppressed the expression of profibrotic mediators in both isolated glomeruli and cultured mesangial cells. An investigation of mechanisms underlying this observation revealed activated ROCK functions through the phosphorylation of JNK and Erk and the nuclear translocation of NF-κB via actin dynamics. Knockdown by siRNA against ROCK1 and ROCK2 showed that ROCK2 but not ROCK1 controls this fibrotic machinery. Further in vivo experiments showed that ROCK2 activity in the renal cortex of db/db mice was elevated compared with control db/m mice. Importantly, oral administration of ROCK2 inhibitor attenuated renal ROCK2 activity, albuminuria, and glomerular fibrosis in db/db mice. These observations indicate that ROCK2 is a key player in the development of diabetic renal injury. Glomerular ROCK2 may be a potential therapeutic target for the treatment of diabetic kidney disease.


Subject(s)
Connective Tissue Growth Factor/biosynthesis , Cytoskeleton/metabolism , Fibrosis/genetics , Glomerular Mesangium/metabolism , NF-kappa B/biosynthesis , Transforming Growth Factor beta/pharmacology , rho-Associated Kinases/metabolism , Actins/metabolism , Animals , Diabetic Nephropathies/metabolism , Enzyme Activation , Glomerular Mesangium/cytology , MAP Kinase Signaling System/drug effects , Male , Mice , Mice, Inbred NOD , rho-Associated Kinases/antagonists & inhibitors
2.
Int J Mol Sci ; 20(6)2019 Mar 16.
Article in English | MEDLINE | ID: mdl-30884801

ABSTRACT

The small GTPase Rho and its downstream effector, Rho-kinase (ROCK), regulate various cellular functions, including organization of the actin cytoskeleton, cell adhesion and migration. A pro-inflammatory lipid mediator, lysophosphatidic acid (LPA), is a potent activator of the Rho/ROCK signalling pathway and has been shown to induce the expression of chemokines and cell adhesion molecules (CAMs). In the present study, we aimed to elucidate the precise mechanism by which ROCK regulates LPA-induced expressions and functions of chemokines and CAMs. We observed that ROCK blockade reduced LPA-induced phosphorylation of IκBα and inhibited NF-κB RelA/p65 phosphorylation, leading to attenuation of RelA/p65 nuclear translocation. Furthermore, small interfering RNA-mediated ROCK isoform knockdown experiments revealed that LPA induces the expression of monocyte chemoattractant protein-1 (MCP-1) and E-selectin via ROCK2 in human aortic endothelial cells (HAECs). Importantly, we found that ROCK2 but not ROCK1 controls LPA-induced monocytic migration and monocyte adhesion toward endothelial cells. These findings demonstrate that ROCK2 is a key regulator of endothelial inflammation. We conclude that targeting endothelial ROCK2 is potentially effective in attenuation of atherosclerosis.


Subject(s)
Atherosclerosis/genetics , Endothelial Cells/drug effects , Lysophospholipids/pharmacology , rho-Associated Kinases/genetics , Actin Cytoskeleton/drug effects , Actin Cytoskeleton/genetics , Active Transport, Cell Nucleus/drug effects , Aorta/cytology , Aorta/metabolism , Atherosclerosis/metabolism , Atherosclerosis/pathology , Cell Adhesion/genetics , Cell Movement/drug effects , Chemokine CCL2/genetics , E-Selectin/genetics , Endothelial Cells/metabolism , Gene Expression Regulation/drug effects , Humans , I-kappa B Kinase/genetics , Monocytes/drug effects , Phosphorylation , Signal Transduction/drug effects , Transcription Factor RelA/genetics , rho-Associated Kinases/metabolism
3.
Int J Mol Sci ; 18(8)2017 Aug 18.
Article in English | MEDLINE | ID: mdl-28820432

ABSTRACT

Podocyte apoptosis is a key process in the onset of diabetic nephropathy. A significant body of evidence shows that the Notch signaling pathway plays a central role in this process. We found that Rho-kinase mediates transforming growth factor ß (TGF-ß)-induced Notch ligand Jag1 expression. Importantly, TGF-ß-mediated podocyte apoptosis was attenuated by Rho-kinase inhibition. Mechanistically, Rho-kinase regulated Jag1 induction via the extracellular signal-regulated kinase (ERK) 1/2 and c-Jun N-terminal kinase (JNK) but not Smad pathways. Consistently, the Rho-kinase inhibitor fasudil prevented albuminuria and the urinary excretion of nephrin in db/db mice and reduced the prevalence of podocyte apoptosis and Jag1 expression. Finally, the expression of Jag1 and apoptosis markers such as Bax and cyclin-dependent kinase inhibitor 1A (CDKN1A) was decreased in podocytes derived from db/db mice treated with fasudil. The present study provides evidence that Rho-kinase plays a key role in podocyte apoptosis. Rho-kinase is an attractive therapeutic target for diabetic nephropathy.


Subject(s)
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/analogs & derivatives , Apoptosis/drug effects , Diabetic Nephropathies/metabolism , Podocytes/drug effects , Receptors, Notch/metabolism , rho-Associated Kinases/antagonists & inhibitors , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/pharmacology , Albuminuria/metabolism , Albuminuria/prevention & control , Animals , Cell Line , Cells, Cultured , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/genetics , Diabetic Nephropathies/etiology , Diabetic Nephropathies/pathology , Jagged-1 Protein/metabolism , Male , Membrane Proteins/urine , Mice , Mitogen-Activated Protein Kinases/metabolism , Podocytes/metabolism , Protein Kinase Inhibitors/pharmacology , Signal Transduction/drug effects , rho-Associated Kinases/metabolism
4.
PLoS One ; 11(1): e0144921, 2016.
Article in English | MEDLINE | ID: mdl-26731185

ABSTRACT

BACKGROUND: Increased short-term blood pressure (BP) variability on 24-hour ambulatory BP monitoring (ABPM) is known to be a risk factor for cardiovascular events. However, very few studies have evaluated the effect of salt restriction on BP variability particularly in hypertensive patients with type 2 diabetes. This study aimed to investigate the effect of salt restriction on systolic BP (SBP) variability. METHODS AND RESULTS: 10 hypertensive patients with type 2 diabetes and not receiving antihypertensive agents were enrolled in the study. After admission, all patients received a salt-restricted diet and appropriate anti-diabetic treatments and were followed up for 7 consecutive days using ABPM. After the 7-day treatment, the median [interquartile range (IQR)] coefficient of variation (CV) for diurnal SBP variability changed from day 1 to day 7-13.0 [10.8 to 16.8] % to 13.3 [9.1 to 18.9] % (P = 0.959)--and the median [IQR] change between days 1 and 7 was -0.3 [-3.2 to 2.9] %. In addition, CV for BP variability and circadian rhythm of BP varied greatly on a day-by-day basis for 7 days, compared to mean BP values. Interestingly, increased SBP variability was associated with greater day-by-day changes in circadian rhythm of BP. CONCLUSIONS: Salt restriction during 7-day hospitalization led to a -0.3 [-3.2 to 2.9] (median [IQR]) % change from baseline in CV for diurnal SBP variability in 10 hypertensive patients with type 2 diabetes not receiving antihypertensive agents. TRIAL REGISTRATION: UMIN Clinical Trials Registry UMIN000016243.


Subject(s)
Blood Pressure , Diabetes Mellitus, Type 2/physiopathology , Hypertension/physiopathology , Sodium Chloride, Dietary/administration & dosage , Aged , Diabetes Mellitus, Type 2/complications , Female , Humans , Hypertension/complications , Male , Middle Aged , Prospective Studies
5.
Am J Physiol Renal Physiol ; 307(5): F571-80, 2014 Sep 01.
Article in English | MEDLINE | ID: mdl-25007875

ABSTRACT

The small GTPase Rho and its downstream effector, Rho-associated coiled-coil containing protein kinase (Rho-kinase), regulate a number of cellular processes, including organization of the actin cytoskeleton, cell adhesion, and migration. While pharmacological inhibitors of Rho-kinase signaling are known to block renal inflammation, the molecular basis for this effect is unclear. Here, we provide evidence that proinflammatory TNF-α promotes mesangial expression of macrophage colony-stimulating factor (M-CSF), a key regulator for the growth and differentiation of mononuclear phagocytes, in a Rho-kinase-dependent manner. Consistent with this observation, TNF-α-mediated renal expression of M-CSF in insulin-resistant db/db mice was downregulated by Rho-kinase inhibition. Small interfering RNA-facilitated knockdown of Rho-kinase isoforms ROCK1 and ROCK2 indicated that both isoforms make comparable contributions to regulation of M-CSF expression in mesangial cells. From a mechanistic standpoint, Western blotting and EMSA showed that Rho-kinase and its downstream target p38 MAPK regulate nuclear translocation of NF-κB RelA/p65 and subsequent DNA binding activity, with no significant effects on IκBα degradation and RelA/p65 phosphorylation. Moreover, we showed that Rho-kinase-mediated cytoskeletal organization is required for the nuclear uptake of RelA/p65. Collectively, these findings identify Rho-kinase as a critical regulator of chemokine expression and macrophage proliferation.


Subject(s)
Macrophage Colony-Stimulating Factor/metabolism , Mesangial Cells/metabolism , Transcription Factor RelA/metabolism , Tumor Necrosis Factor-alpha/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism , rho-Associated Kinases/metabolism , Actins/metabolism , Animals , Cell Line , Cell Proliferation , Chemokines/metabolism , Cytoskeleton/metabolism , In Vitro Techniques , Macrophages/cytology , Male , Mesangial Cells/cytology , Mice , Mice, Inbred Strains , Models, Animal , Protein Transport
6.
Clin Exp Nephrol ; 18(6): 844-52, 2014 Dec.
Article in English | MEDLINE | ID: mdl-24463961

ABSTRACT

BACKGROUND: Sphingosine-1-phosphate (S1P) is reportedly involved in the pathogenesis of kidney disease; however, the precise role played by S1P in renal disorders still remains controversial. Rho kinase plays an important role in the development of diabetic nephropathy by inducing glomerular and tubulointerstitial fibrosis. Rho kinase is known to be stimulated by S1P through its specific receptor, S1P2 receptor (S1P2). Hence, we investigated whether S1P-S1P2 signaling plays a role in the epithelial-mesenchymal transition (EMT) through Rho kinase activation in renal tubules. METHOD: To characterize the distribution of the S1P2, an immunohistochemical examination of the receptor was performed in the kidney of the non-diabetic and diabetic mice. Next, we examined Rho kinase activity as well as E-cadherin and alpha-smooth muscle actin (α-SMA) expression by real-time RT-PCR and western blotting in cultured rat tubular epithelial cells under S1P stimulation with and without a Rho kinase inhibitor and an S1P2 blocker. In addition, the distribution of E-cadherin and α-SMA was examined by immunocytochemistry. RESULT: S1P2 was expressed mainly in the renal tubules; expression was intense in collecting ducts and distal tubules compared to other segments. S1P induced activation of Rho kinase through the S1P2, which changed the distribution of E-cadherin and increased the expression of α-SMA. CONCLUSION: Rho kinase activation by S1P via S1P2 initiated EMT changes in cultured renal tubular cells. Our results suggest that excessive stimulation of S1P might facilitate renal fibrosis via activation of Rho kinase through S1P2.


Subject(s)
Cell Differentiation/drug effects , Kidney Tubules/pathology , Lysophospholipids/pharmacology , Receptors, Lysosphingolipid/physiology , Sphingosine/analogs & derivatives , rho-Associated Kinases/physiology , Actins/physiology , Animals , Cadherins/physiology , Cell Differentiation/physiology , Cells, Cultured , Epithelial Cells/pathology , Epithelial Cells/physiology , Epithelial-Mesenchymal Transition/physiology , Kidney Tubules/physiology , Male , Mice , Mice, Knockout , Receptors, Leptin/deficiency , Receptors, Leptin/genetics , Receptors, Leptin/physiology , Sphingosine/pharmacology
7.
Biochem Biophys Res Commun ; 435(2): 171-5, 2013 May 31.
Article in English | MEDLINE | ID: mdl-23665024

ABSTRACT

The process of atherosclerosis is affected by interactions among numerous biological pathways. Accumulating evidence shows that endoplasmic reticulum (ER) stress plays a crucial role in the development of atherosclerosis. Rho-kinase is an effector of small GTP-binding protein Rho, and has been implicated as an atherogenic factor. Previous studies demonstrated that fasudil, a specific Rho-kinase inhibitor, exerts a cardioprotective effect by downregulating ER stress signaling. However, the molecular link between ER stress and Rho-kinase in endothelial cells has not been elucidated. In this study, we investigated the mechanisms by which fasudil regulates endothelial inflammation during ER stress. Tunicamycin, an established ER stress inducer, increased vascular cellular adhesion molecule (VCAM)-1 expression in endothelial cells. Intriguingly, fasudil inhibited VCAM-1 induction. From a mechanistic stand point, fasudil inhibited expression of activating transcription factor (ATF)4 and subsequent C/EBP homologous protein (CHOP) induction by tunicamycin. Furthermore, fasudil attenuated tunicamycin-induced phophorylation of p38MAPK that is crucial for the atherogenic response during ER stress. These findings indicate that Rho-kinase regulates ER stress-mediated VCAM-1 induction by ATF4- and p38MAPK-dependent signaling pathways. Rho-kinase inhibition by fasudil would be an important therapeutic approach against atherosclerosis, in particular, under conditions of ER stress.


Subject(s)
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/analogs & derivatives , Endoplasmic Reticulum Stress/physiology , Endothelial Cells/metabolism , Unfolded Protein Response/physiology , Vascular Cell Adhesion Molecule-1/metabolism , rho-Associated Kinases/metabolism , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/pharmacology , Cells, Cultured , Endoplasmic Reticulum Stress/drug effects , Endothelial Cells/drug effects , Humans , Protein Folding/drug effects , Protein Kinase Inhibitors/pharmacology , Stress, Physiological , Unfolded Protein Response/drug effects
8.
Kidney Int ; 84(3): 545-54, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23615507

ABSTRACT

The small GTPase Rho and its effector Rho-kinase are involved in the pathogenesis of diabetic nephropathy. Accumulating evidence shows that hypoxia-inducible factor-1α (HIF-1α) is a key regulator of renal sclerosis under diabetic conditions. However, the interactions of Rho-kinase and HIF-1α in the development of renal dysfunction have not been defined. Here, we assessed whether Rho-kinase blockade attenuates HIF-1α induction and the subsequent fibrotic response using type 2 diabetic mice and cultured mesangial cells. Fasudil, a Rho-kinase inhibitor, reduced urinary albumin excretion, mesangial matrix expansion, and the expression of fibrotic mediators in db/db mice. Mechanistically, HIF-1α accumulation and the expression of its target genes that contribute to diabetic glomerulosclerosis were also prevented by fasudil in the renal cortex. In mesangial cells, Rho/Rho-kinase signaling was activated under hypoxic conditions. Further in vitro studies showed that pharmacological and genetic inhibition of Rho-kinase promoted proteasomal HIF-1α degradation, which subsequently suppressed HIF-1-dependent profibrotic gene expression by upregulation of prolyl hydroxylase 2. Thus, we found a previously unrecognized renoprotective mechanism for the effects of Rho-kinase inhibition and this could be a potential therapeutic target for the treatment of diabetic nephropathy.


Subject(s)
Diabetes Mellitus, Type 2/metabolism , Diabetic Nephropathies/metabolism , Diabetic Nephropathies/prevention & control , Disease Progression , Down-Regulation/drug effects , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , rho-Associated Kinases/antagonists & inhibitors , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/analogs & derivatives , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/pharmacology , Albuminuria/metabolism , Albuminuria/prevention & control , Animals , Diabetes Mellitus, Type 2/pathology , Diabetic Nephropathies/pathology , Disease Models, Animal , Fibrosis , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor-Proline Dioxygenases/metabolism , Kidney Cortex/metabolism , Kidney Cortex/pathology , Male , Mice , Mice, Mutant Strains , Protein Kinase Inhibitors/pharmacology , rho-Associated Kinases/drug effects , rho-Associated Kinases/metabolism
9.
Exp Neurol ; 247: 438-46, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23337773

ABSTRACT

The Rho/Rho-kinase signaling pathway has been shown to be involved in the complications of diabetes. In this study, we found that fasudil, a specific Rho-kinase inhibitor, had a beneficial effect on the motor nerve conduction velocity (MNCV), which is delayed in rats with streptozotocin (STZ)-induced diabetes. Cadherin-dependent adherens junctions (AJs) in myelinating Schwann cells, necessary for proper myelin formation and rapid propagation of action potentials, are regulated by Rho/Rho-kinase signaling. These AJ structures are maintained by E-cadherin and catenin complexes such as ß-catenin and p120 catenin. To elucidate the mechanism underlying the effect of fasudil on MNCV, we examined alterations in AJ structure in the peripheral nerves of the experimental rats. Our results showed that the activities of Rho and Rho-kinase increased simultaneously in the sciatic nerves of the diabetic rats. Fasudil restored the MNCV by suppressing the up-regulation of the Rho-kinase. In the diabetic state, enhanced Rho and Rho-kinase activity reduced p120 catenin expression and altered the distribution of p120 catenin and E-cadherin, which are normally localized in the paranodal compartment of the nodes of Ranvier and Schmidt-Lanterman incisures where autotypic AJs stabilize myelin structure. Fasudil restored normal p120 catenin expression and the distribution of p120 catenin and E-cadherin in the myelin sheath. In conclusion, reduced expression and altered distribution of the adhesion molecules in the myelin sheath might contribute to the slowing of the MNCV in the diabetic rats. Fasudil, through its effect on the distribution of the adhesion-related molecules, might prevent slowing of the MNCV.


Subject(s)
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/analogs & derivatives , Cadherins/metabolism , Diabetes Mellitus, Experimental/drug therapy , Neural Conduction/drug effects , Protein Kinase Inhibitors/pharmacology , Schwann Cells/drug effects , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/pharmacology , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/therapeutic use , Animals , Body Weight/drug effects , Catenins/metabolism , Diabetes Mellitus, Experimental/pathology , Disease Models, Animal , Electric Stimulation , Gene Expression Regulation/drug effects , Male , Nerve Tissue Proteins/metabolism , Protein Kinase Inhibitors/therapeutic use , Rats , Rats, Sprague-Dawley , Rho Factor/metabolism , Schwann Cells/metabolism , Sciatic Nerve/drug effects , Sciatic Nerve/physiopathology , beta Catenin/metabolism , rho-Associated Kinases/metabolism , Delta Catenin
10.
PLoS One ; 7(12): e51171, 2012.
Article in English | MEDLINE | ID: mdl-23226566

ABSTRACT

BACKGROUND: We aimed to examine associations among serum 25-hydroxyvitamin D (25OHD) levels, 1,25-dihyroxyvitamin D (1,25OHD) levels, vitamin D receptor (VDR) polymorphisms, and renal function based on estimated glomerular filtration rate (eGFR) in patients with type 2 diabetes. METHODS: In a cross-sectional study of 410 patients, chronic kidney disease (CKD) stage assessed by eGFR was compared with 25OHD, 1,25OHD, and VDR FokI (rs10735810) polymorphisms by an ordered logistic regression model adjusted for the following confounders: disease duration, calendar month, use of angiotensin converting enzyme inhibitors/angiotensin receptor blockers or statins, and serum calcium, phosphate, and intact parathyroid hormone levels. RESULTS: 1,25OHD levels, rather than 25OHD levels, showed seasonal oscillations; peak levels were seen from May to October and the lowest levels were seen from December to February. These findings were evident in patients with CKD stage 3 ~ 5 but not stage 1 ~ 2. eGFR was in direct proportion to both 25OHD and 1,25OHD levels (P<0.0001), but it had stronger linearity with 1,25OHD (r = 0.73) than 25OHD (r = 0.22) levels. Using multivariate analysis, 1,25OHD levels (P<0.001), but not 25OHD levels, were negatively associated with CKD stage. Although FokI polymorphisms by themselves showed no significant associations with CKD stage, a significant interaction between 1,25OHD and FokITT was observed (P = 0.008). The positive association between 1,25OHD and eGFR was steeper in FokICT and CC polymorphisms (r = 0.74) than FokITT polymorphisms (r = 0.65). CONCLUSIONS: These results suggest that higher 1,25OHD levels may be associated with better CKD stages in patients with type 2 diabetes and that this association was modified by FokI polymorphisms.


Subject(s)
Deoxyribonucleases, Type II Site-Specific/genetics , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/physiopathology , Kidney Function Tests , Polymorphism, Genetic , Receptors, Calcitriol/genetics , Vitamin D/blood , Adult , Aged , Aged, 80 and over , Diabetes Mellitus, Type 2/blood , Female , Genetic Predisposition to Disease , Glomerular Filtration Rate , Humans , Kidney Failure, Chronic/blood , Kidney Failure, Chronic/genetics , Kidney Failure, Chronic/physiopathology , Logistic Models , Male , Middle Aged , Seasons , Vitamin D/analogs & derivatives , Young Adult
11.
Anticancer Res ; 31(10): 3253-7, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21965733

ABSTRACT

BACKGROUND: Malignant glioma is an invasive disease of the central nervous system. One of the factors that regulate growth of these tumors is expression of epidermal growth factor receptor (EGFR) in the cells. This study investigated the effects of down-regulation of EGFR on cell proliferation, cell cycle and cytotoxicity to antineoplastic agent. MATERIALS AND METHODS: A short hairpin RNA transcription vector targeting EGFR was transfected into KNS42 cells. Growth curve, cell cycle and sensitivity to temozolomide of the cells were assessed. RESULTS: Transfection inhibited EGFR expression by 50.5%. It prolonged cell doubling time by 25.7%. However, it did not meaningfully alter the cell cycle populations nor increase sensitivity to temozolomide. CONCLUSION: Suppressing expression of EGFR inhibited cell proliferation. However, unlike PTEN expression or ROCK1 down-regulation, it did not alter the cell cycle or increase sensitivity to temozolomide.


Subject(s)
Dacarbazine/analogs & derivatives , Down-Regulation/drug effects , ErbB Receptors/metabolism , Glioma/pathology , Cell Cycle/drug effects , Cell Death/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Dacarbazine/pharmacology , Drug Screening Assays, Antitumor , Glioma/enzymology , Humans , RNA, Small Interfering/metabolism , Temozolomide , Transfection , rho-Associated Kinases/metabolism
12.
Biochem Biophys Res Commun ; 411(4): 798-803, 2011 Aug 12.
Article in English | MEDLINE | ID: mdl-21787749

ABSTRACT

Thrombin has been shown to increase expression of chemokines such as monocyte chemoattractant protein 1 (MCP-1) in endothelial cells, leading to the development of atherosclerosis. However, the precise mechanism of this induction remains unknown. In the present study, we investigated whether the small G protein RhoA, and its effector, Rho-kinase are involved in MCP-1 induction by thrombin in endothelial cells. Y-27632, a specific Rho-kinase inhibitor, potently inhibited MCP-1 induction by thrombin. Y-27632 significantly decreased the chemotactic activity of thrombin-stimulated supernatants of endothelial cells on monocytes. Importantly, fasudil, a specific Rho-kinase inhibitor, attenuated MCP-1 gene expression in the aorta of db/db mice. Y-27632 attenuated thrombin-mediated phosphorylation of p38MAPK and p65, indicating that Rho-kinase mediates thrombin-induced MCP-1 expression through p38MAPK and NF-κB activation. Our findings demonstrate that the Rho/Rho-kinase signaling pathway plays a critical role in thrombin-mediated MCP-1 expression and function, and suggest that Rho/Rho-kinase may be an important target in the development of new therapeutic strategies for atherosclerosis.


Subject(s)
Chemokine CCL2/biosynthesis , Endothelium, Vascular/metabolism , NF-kappa B/metabolism , Thrombin/physiology , p38 Mitogen-Activated Protein Kinases/metabolism , rho-Associated Kinases/metabolism , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/analogs & derivatives , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/pharmacology , Amides/pharmacology , Animals , Aorta/metabolism , Cell Movement , Cells, Cultured , Chemokine CCL2/genetics , Gene Expression , Humans , Mice , Mice, Inbred Strains , Monocytes/physiology , Protein Kinase Inhibitors/pharmacology , Pyridines/pharmacology , Thrombin/genetics , rho-Associated Kinases/antagonists & inhibitors
13.
Anticancer Res ; 30(9): 3509-14, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20944130

ABSTRACT

BACKGROUND: Malignant glioma is one of the most intractable diseases in the human body. Rho-kinase (ROCK) is overexpressed and has been proposed as the main cause for the refractoriness of the disease. Since efficacious treatment is required, this study investigated the effect of inhibition of ROCK isoforms. MATERIALS AND METHODS: The short hairpin RNA transcription vector was transfected into the RT2 rat glioma cell line and the characteristics of the cells were investigated. The effect of nimustine hydrochloride (ACNU) anti-neoplastic agent on cells was also measured. RESULTS: Inhibition of ROCK isoforms did not alter cell growth. Cell cycle analysis revealed that ROCK1 down-regulation reduced the G(0) phase population and ROCK2 down-regulation reduced the G(2)/M phase population. When ROCK1-down-regulated cells were exposed to ACNU, they demonstrated susceptibility to the agent. CONCLUSION: The roles of ROCK1 and ROCK2 may be different in glioma cells. Furthermore, the combination of ROCK1 down-regulation and an anti-neoplastic agent may be useful for the therapy of malignant glioma.


Subject(s)
Glioma/metabolism , rho-Associated Kinases/metabolism , Animals , Antineoplastic Agents/pharmacology , Cell Cycle/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Gene Knockdown Techniques , Glioma/genetics , Humans , Immunoblotting , Isoenzymes , Nimustine/pharmacology , RNA, Small Interfering , Rats , Transfection , rho-Associated Kinases/genetics
14.
Biochem Biophys Res Commun ; 402(4): 725-30, 2010 Nov 26.
Article in English | MEDLINE | ID: mdl-20977889

ABSTRACT

Macrophage accumulation has been implicated in the pathogenesis of inflammatory glomerular disease. Monocyte chemoattractant protein-1 (MCP-1) plays a central role in recruiting monocytes to the glomeruli. Tumor necrosis factor-α (TNF-α) has been shown to induce MCP-1 expression in mesangial cells, although the precise mechanisms remain unclear. We previously demonstrated that RhoA and its effector, Rho-kinase (Rho-associated coiled-coil containing protein kinase, ROCK), are involved in the pathogenesis of diabetic nephropathy. However, its role in MCP-1 induction by TNF-α has not been elucidated. In the present study, we investigated whether the Rho/Rho-kinase signaling pathway regulates the TNF-α-mediated induction of MCP-1 in mesangial cells. Exposure of mouse mesangial cells (MES-13) to TNF-α resulted in an increase of MCP-1 expression (by RT-PCR) and secretion into the medium (by ELISA). Pull down and Western blot analysis revealed that TNF-α activated RhoA and Rho-kinase. Based on these observations, we speculated that the Rho/Rho-kinase signaling pathway may be involved in MCP-1 induction by TNF-α. In agreement with this concept, Y-27632, a specific Rho-kinase inhibitor, attenuated TNF-α-mediated induction of MCP-1. We demonstrated that Y-27632 inhibited TNF-α-mediated monocyte migration and attenuated TNF-α-mediated p38 MAPK activation. Based on these data we infer that Y-27632 inhibits TNF-α-induced MCP-1 expression, secretion and function through inhibition of Rho-kinase and p38 MAPK activity. Our study suggests that Rho/Rho-kinase is an important therapeutic target of monocyte recruitment and accumulation within the glomerulus in inflammatory renal disease.


Subject(s)
Chemokine CCL2/metabolism , Mesangial Cells/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism , rho-Associated Kinases/metabolism , Amides/pharmacology , Animals , Cell Line , Chemotaxis , Enzyme Inhibitors/pharmacology , Glomerulonephritis/metabolism , Mesangial Cells/drug effects , Mice , Pyridines/pharmacology , Signal Transduction , Tumor Necrosis Factor-alpha/pharmacology , Tumor Necrosis Factor-alpha/physiology , rho-Associated Kinases/antagonists & inhibitors
15.
Intern Med ; 48(18): 1621-7, 2009.
Article in English | MEDLINE | ID: mdl-19755764

ABSTRACT

OBJECTIVE: To investigate the relationship between homeostasis model assessment for insulin resistance (HOMA-R) and urinary albumin excretion in Japanese and clarify gender difference in albuminuria-related insulin resistance. METHODS: The subject group consisted of 752 Japanese who had no history of diabetes, hypertension or dyslipidemia. After anthropometric examination, fasting blood samples were obtained to determine plasma glucose (FPG), lipids and HOMA-R. The urinary excretion of albumin in the first void urine was expressed as the creatinine ratio (ACR, mg/gCr). Estimated glomerular filtration rate (eGFR) was calculated from serum creatinine using the formula for Japanese. RESULTS: HOMA-R showed a significant correlation with ACR, and the correlation between HOMA-R and ACR was evident in the subjects with central obesity, whereas no significant correlation was found in the non-obese subjects. There was no correlation between HOMA-R and eGFR. HOMA-R increased according to the quintile of ACR and followed a significant trend. This association was obvious in males; however, in females there was no significant trend. Multiple regression analysis revealed that HOMA-R showed a significant correlation with age, waist circumference, blood pressure and serum triglyceride. In addition, ACR exhibited an independent association with HOMA-R. The association of HOMA-R and ACR was observed only in males, and was not present in females. CONCLUSION: Microalbuminuria is associated with insulin resistance in Japanese, where central obesity might play an essential role. This association is gender-specific suggesting the involvement of sex hormones in the pathogenesis of albuminuria-related insulin resistance.


Subject(s)
Albuminuria/physiopathology , Insulin Resistance/physiology , Adult , Asian People , Blood Glucose/metabolism , Creatinine/blood , Diabetic Nephropathies/etiology , Diabetic Nephropathies/physiopathology , Female , Glomerular Filtration Rate , Homeostasis , Humans , Japan , Lipids/blood , Male , Middle Aged , Models, Biological , Obesity, Abdominal/physiopathology , Risk Factors , Sex Characteristics
16.
J Atheroscler Thromb ; 16(3): 250-5, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19556726

ABSTRACT

AIM: Menopause is a risk factor for cardiovascular disease (CVD) in women because of the reduction in endogenous estrogen. Recently, single nucleotide polymorphisms (SNPs) of the estrogen receptor alpha (ESR-1) gene (c.454-397T>C) associated with the prognosis of myocardial infarction in postmenopausal women were identified; however, the mechanism by which genetic variation of ESR-1 contributes to the pathogenesis of CVD is unknown. Circulating levels of adipokines and inflammatory cytokines predict CVD risk; hence, this study aimed to investigate whether ESR-1 genotypes (c.454-397T>C) might influence circulating levels of adipokines and inflammatory cytokines in postmenopausal women with type 2 diabetes. METHODS: Sixty-three postmenopausal women with type 2 diabetes were recruited. Serum levels of adiponectin, resistin, interleukin-6 (IL-6), and high-sensitive C-reactive protein (hs-CRP) were determined. RESULTS: The genotype of ESR-1 was closely associated with serum adiponectin, which was decreased in subjects with the T allele and was lowest in those with the T/T genotype. Multiple logistic regression analysis revealed independent contribution of the homozygote for the T allele to low serum levels of adiponectin. CONCLUSION: The T allele of the c.454-397T>C SNP of ESR-1 is associated with low serum levels of adiponectin, which may lead to a high risk of CVD in postmenopausal women.


Subject(s)
Adiponectin/blood , Diabetes Mellitus, Type 2/genetics , Estrogen Receptor alpha/genetics , Polymorphism, Single Nucleotide , Postmenopause , Aged , Alleles , Cardiovascular Diseases/etiology , Diabetes Mellitus, Type 2/blood , Female , Genotype , Humans , Middle Aged , Regression Analysis , Risk Factors
17.
Anticancer Res ; 29(1): 235-42, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19331155

ABSTRACT

BACKGROUND: Malignancies affecting the central nervous system are intractable to conventional therapies thereby requiring an alternative strategy, such as ultrasound irradiation. MATERIALS AND METHODS: We originally designed a transducer for intracranial insonation and investigated the effect of 210.4 kHz ultrasound on malignant glioma cells. RESULTS: The insonation of 2.61 W/cm2 effectively disrupted the malignant cells. This effect was reinforced by the echo-contrast agent, Levovist. The condition was applied to tumor-bearing animals and external insonation inhibited subcutaneous tumor growth. It also repressed the growth of intracranially implanted tumors and prolonged survival of the animals. When Levovist was stereotactically injected into the tumors, the effect of insonation was significantly enhanced. CONCLUSION: A neuronavigation system or stereotactic device has been used commonly for patients with brain tumor. Administration of combination therapy consisting of insonation and a local echo-contrast agent will have a role in improving the treatment for malignant gliomas.


Subject(s)
Brain Neoplasms/diagnostic imaging , Brain Neoplasms/therapy , Glioma/diagnostic imaging , Glioma/therapy , Microbubbles , Polysaccharides , Sonication/methods , Animals , Cell Line, Tumor , Cell Membrane/diagnostic imaging , Contrast Media , Female , Humans , Rats , Rats, Inbred F344 , Ultrasonic Therapy/methods , Ultrasonography , Xenograft Model Antitumor Assays
18.
Intern Med ; 42(9): 850-5, 2003 Sep.
Article in English | MEDLINE | ID: mdl-14518675

ABSTRACT

A 57-year-old woman was admitted to our hospital because of severe dyspnea due to pulmonary hemorrhage and rapidly progressive renal failure. The patient was positive for perinuclear pattern anti-neutrophil cytoplasmic antibody (p-ANCA) and was manifested with gastrointestinal bleeding and brain hemorrhage. Thus, she was diagnosed as having microscopic polyangiitis (MPA). Laboratory examination demonstrated severe thrombocytopenia, increased prothrombin time and a high concentration of fibrin degradation products. In addition, the elevated plasma levels of D-dimer, thrombin-antithrombin complex and plasmin-plasmin inhibitor complex led us to make a diagnosis of disseminated intravascular coagulation (DIC). Complication of DIC was considered to have caused further deterioration in bleeding tendency due to MPA in the present case. The patient was treated with plasma exchange, hemodialysis, administration of corticosteroid including pulse therapy and cyclophosphamide. Continuous infusion of gabexate mesilate proved effective for improvement of systemic bleeding tendency. However, she finally died of severe infectious diseases. In conclusion, it is suggested that ANCA-associated vasculitis could be accompanied by DIC and gabexate mesilate may be a useful therapeutic agent for these disorders.


Subject(s)
Antibodies, Antineutrophil Cytoplasmic/immunology , Disseminated Intravascular Coagulation/immunology , Hemorrhage/immunology , Vasculitis/immunology , Anticoagulants/therapeutic use , Disseminated Intravascular Coagulation/drug therapy , Disseminated Intravascular Coagulation/etiology , Fatal Outcome , Female , Gabexate/therapeutic use , Hemorrhage/etiology , Humans , Middle Aged , Vasculitis/complications
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