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1.
Biochem Biophys Res Commun ; 649: 32-38, 2023 03 15.
Article in English | MEDLINE | ID: mdl-36739697

ABSTRACT

The small GTPase Rho and its effector Rho-kinase (ROCK) are activated in the diabetic kidney, and recent studies decade have demonstrated that ROCK signaling is an integral pathway in the progression of diabetic kidney disease. We previously identified the distinct role of ROCK1, an isoform of ROCK, in fatty acid metabolism in diabetic glomeruli. However, the effect of pharmacological intervention for ROCK1 is not clear. In the present study, we show that the inhibition of ROCK1 by Y-27632 and fasudil restores fatty acid oxidation in the glomeruli. Mechanistically, these compounds optimize fatty acid utilization and redox balance in mesangial cells via AMPK phosphorylation and the subsequent induction of PGC-1α. A further in vivo study showed that the inhibition of ROCK1 suppressed the downregulation of the fatty acid oxidation-related gene expression in glomeruli and mitochondrial fragmentation in the mesangial cells of db/db mice. These observations indicate that ROCK1 could be a promising therapeutic target for diabetic kidney disease through a mechanism that improves glomerular fatty acid metabolism.


Subject(s)
Diabetes Mellitus , Diabetic Nephropathies , Mice , Animals , Diabetic Nephropathies/drug therapy , Diabetic Nephropathies/metabolism , rho-Associated Kinases/metabolism , Kidney Glomerulus/metabolism , Kidney/metabolism , Signal Transduction , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Protein Kinase Inhibitors/metabolism , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/pharmacology , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/therapeutic use , Diabetes Mellitus/metabolism
2.
Endocr J ; 70(8): 771-776, 2023 Aug 28.
Article in English | MEDLINE | ID: mdl-37468263

ABSTRACT

Diabetic nephropathy is a public health problem worldwide. Our understanding of the molecular machinery, as well as the clinical therapies for diabetic nephropathy, has evolved dramatically in recent years. However, even with this progress, there are residual risks of kidney failure and cardiovascular events in patients with diabetes. Rho-associated, coiled-coil-containing protein kinase (ROCK) is activated in response to various pathologic stimuli in the context of diabetes. The contribution of ROCK has been investigated in vivo using gene deletion rodent models and specific inhibitors, which are providing key insights into the pathologic function of ROCK in diabetic nephropathy. ROCK has two isoforms, ROCK1 and ROCK2. Both isoforms are expressed in the kidney, including mesangial cells, podocytes, and endothelial cells. ROCK1 blunts AMP-activated protein kinase (AMPK), while ROCK2 negatively regulates peroxisome proliferator-activated receptor α (PPARα) to inhibit fatty acid oxidation, both of which lead to structural and functional impairment of glomeruli in diabetes. Of note, ROCK signaling is activated in the kidney of animal models and patients with diabetes. In addition, an observational study has shown that fasudil hydrochloride, an ATP-competitive selective ROCK inhibitor, significantly attenuated proteinuria among patients with diabetes. These findings highlight the promising prospects for the development of a ROCK-centered approach against the progression of diabetic nephropathy.


Subject(s)
Diabetes Mellitus , Diabetic Nephropathies , Animals , Diabetic Nephropathies/metabolism , rho-Associated Kinases/genetics , rho-Associated Kinases/metabolism , Endothelial Cells/metabolism , Kidney/metabolism , Signal Transduction , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Diabetes Mellitus/pathology
3.
Kidney Int ; 102(3): 536-545, 2022 09.
Article in English | MEDLINE | ID: mdl-35597365

ABSTRACT

Dysregulation of fatty acid utilization is increasingly recognized as a significant component of diabetic kidney disease. Rho-associated, coiled-coil-containing protein kinase (ROCK) is activated in the diabetic kidney, and studies over the past decade have illuminated ROCK signaling as an essential pathway in diabetic kidney disease. Here, we confirmed the distinct role of ROCK1, an isoform of ROCK, in fatty acid metabolism using glomerular mesangial cells and ROCK1 knockout mice. Mesangial cells with ROCK1 deletion were protected from mitochondrial dysfunction and redox imbalance driven by transforming growth factor ß, a cytokine upregulated in diabetic glomeruli. We found that high-fat diet-induced obese ROCK1 knockout mice exhibited reduced albuminuria and histological abnormalities along with the recovery of impaired fatty acid utilization and mitochondrial fragmentation. Mechanistically, we found that ROCK1 regulates the induction of critical mediators in fatty acid metabolism, including peroxisome proliferator-activated receptor gamma coactivator 1α, carnitine palmitoyltransferase 1, and widespread program-associated cellular metabolism. Thus, our findings highlight ROCK1 as an important regulator of energy homeostasis in mesangial cells in the overall pathogenesis of diabetic kidney disease.


Subject(s)
Diabetes Mellitus , Diabetic Nephropathies , rho-Associated Kinases , Animals , Diabetic Nephropathies/genetics , Diabetic Nephropathies/metabolism , Fatty Acids/metabolism , Lipid Metabolism , Mice , Mice, Knockout , Signal Transduction , rho-Associated Kinases/metabolism
4.
Nutr Metab Cardiovasc Dis ; 32(4): 1035-1044, 2022 04.
Article in English | MEDLINE | ID: mdl-35115208

ABSTRACT

BACKGROUND AND AIMS: To investigate the superiority of individualized dietary advice based on dietary assessment for patients with type 2 diabetes. METHODS AND RESULTS: A total of 136 Japanese adults with type 2 diabetes were randomized into either individualized or conventional dietary advice groups after dietary assessment using a self-administered brief-type diet history questionnaire. Both participants received three 30-min face-to-face dietary advice sessions by dietitians at 1, 3, and 5 months from study entry. The individualized group received dietary advice based on individual dietary intakes. The conventional group received dietary advice using generalized pamphlets. The primary outcome was the change in HbA1c over 6 months, and secondary outcomes were changes in weight, serum triglyceride, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and dietary intakes. In total, 126 participants were included in the analysis. After adjustment for age, sex, and baseline measurements, HbA1c significantly decreased larger in the individualized group [-1.1%, (95% CI: -1.3 to -0.8)] than the conventional group [-0.7% (95% CI: -1.0 to -0.4)] (P = 0.0495). The individualized group significantly decreased weight, serum triglyceride, and LDL-C, and significantly increased HDL-C, without a significant difference to the conventional group. In dietary changes, the individualized group decreased intakes of energy, confectioneries, meats, oil and fats, and sugar-sweetened beverages. The conventional group decreased alcohol intake and increased total fat and saturated fatty acid intakes. CONCLUSIONS: Individualized dietary advice among patients with type 2 diabetes was superior to conventional dietary advice in lowering HbA1c. TRIAL REGISTRATION: UMIN000037268 (https://www.umin.ac.jp/ctr/index.htm) in July 4, 2019.


Subject(s)
Diabetes Mellitus, Type 2 , Patient Education as Topic , Adult , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Counseling/methods , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/diet therapy , Glycated Hemoglobin/metabolism , Humans , Precision Medicine , Triglycerides/blood
5.
Histochem Cell Biol ; 153(2): 111-119, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31734714

ABSTRACT

Glycolaldehyde (GA) is a highly reactive hydroxyaldehyde and one of the glycolytic metabolites producing advanced glycation endproducts (AGEs), but its toxicity toward neurons and Schwann cells remains unclear. In the present study, we found that GA exhibited more potent toxicity than other AGE precursors (glyceraldehyde, glyoxal, methylglyoxal and 3-deoxyglucosone) against immortalized IFRS1 adult rat Schwann cells and ND7/23 neuroblastoma × neonatal rat dorsal root ganglion (DRG) neuron hybrid cells. GA affected adult rat DRG neurons and ND7/23 cells more severely than GA-derived AGEs, and exhibited concentration- and time-dependent toxicity toward ND7/23 cells (10 < 100 < 250 < 500 µM; 6 h < 24 h). Treatment with 500 µM GA significantly up-regulated the phosphorylation of c-jun N-terminal kinase (JNK) and p-38 mitogen-activated kinase (p-38 MAPK) in ND7/23 cells. Furthermore, GA-induced ND7/23 cell death was significantly inhibited due to co-treatment with 10 µM of the JNK inhibitor SP600125 or the p-38 MAPK inhibitor SB239063. These findings suggest the involvement of JNK and p-38 MAPK-signaling pathways in GA-induced neuronal cell death and that enhanced GA production under diabetic conditions might be involved in the pathogenesis of diabetic neuropathy.


Subject(s)
Acetaldehyde/analogs & derivatives , JNK Mitogen-Activated Protein Kinases/metabolism , Sensory Receptor Cells/drug effects , Signal Transduction/drug effects , p38 Mitogen-Activated Protein Kinases/metabolism , Acetaldehyde/pharmacology , Animals , Cell Death/drug effects , Cells, Cultured , Enzyme Activation/drug effects , Female , Rats , Rats, Wistar , Sensory Receptor Cells/metabolism
6.
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
7.
Int J Mol Sci ; 20(14)2019 Jul 10.
Article in English | MEDLINE | ID: mdl-31295940

ABSTRACT

Diabetic kidney disease (DKD) remains the leading cause of end-stage renal disease (ESRD) and is therefore a major burden on the healthcare system. Patients with DKD are highly susceptible to developing cardiovascular disease, which contributes to increased morbidity and mortality rates. While progress has been made to inhibit the acceleration of DKD, current standards of care reduce but do not eliminate the risk of DKD. There is growing appreciation for the role of inflammation in modulating the process of DKD. The focus of this review is on providing an overview of the current status of knowledge regarding the pathologic roles of inflammation in the development of DKD. Finally, we summarize recent therapeutic advances to prevent DKD, with a focus on the anti-inflammatory effects of newly developed agents.


Subject(s)
Diabetic Nephropathies/etiology , Disease Susceptibility , Inflammation/complications , Animals , Biomarkers , Diabetic Nephropathies/metabolism , Diabetic Nephropathies/prevention & control , Diabetic Nephropathies/therapy , Humans , Inflammation Mediators/metabolism , Signal Transduction
8.
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
9.
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
10.
Int J Mol Sci ; 18(5)2017 May 18.
Article in English | MEDLINE | ID: mdl-28524098

ABSTRACT

Diabetic nephropathy (DN) is a major cause of end-stage renal disease (ESRD) worldwide. Glycemic and blood pressure (BP) control are important but not sufficient to attenuate the incidence and progression of DN. Sodium-glucose cotransporter (SGLT) 2 inhibitors are a new class of glucose-lowering agent suggested to exert renoprotective effects in glucose lowering-dependent and independent fashions. Experimental studies have shown that SGLT2 inhibitors attenuate DN in animal models of both type 1 diabetes (T1D) and type 2 diabetes (T2D), indicating a potential renoprotective effect beyond glucose reduction. Renoprotection by SGLT2 inhibitors has been demonstrated in T2D patients with a high cardiovascular risk in randomized controlled trials (RCTs). These favorable effects of SGLT2 inhibitors are explained by several potential mechanisms, including the attenuation of glomerular hyperfiltration, inflammation and oxidative stress. In this review article, we discuss the renoprotective effects of SGLT2 inhibitors by integrating experimental findings with the available clinical data.


Subject(s)
Diabetic Nephropathies/drug therapy , Sodium-Glucose Transporter 2 Inhibitors , Sodium-Glucose Transporter 2/metabolism , Animals , Cardiovascular Diseases/drug therapy , Cardiovascular Diseases/metabolism , Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/drug therapy , Diabetic Nephropathies/metabolism , Humans , Phlorhizin/therapeutic use , Randomized Controlled Trials as Topic
11.
Int J Mol Sci ; 17(8)2016 Jul 29.
Article in English | MEDLINE | ID: mdl-27483245

ABSTRACT

An increase in the rates of morbidity and mortality associated with diabetic complications is a global concern. Glycemic control is important to prevent the development and progression of diabetic complications. Various classes of anti-diabetic agents are currently available, and their pleiotropic effects on diabetic complications have been investigated. Incretin-based therapies such as dipeptidyl peptidase (DPP)-4 inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1RA) are now widely used in the treatment of patients with type 2 diabetes. A series of experimental studies showed that incretin-based therapies have beneficial effects on diabetic complications, independent of their glucose-lowering abilities, which are mediated by anti-inflammatory and anti-oxidative stress properties. Based on these findings, clinical studies to assess the effects of DPP-4 inhibitors and GLP-1RA on diabetic microvascular and macrovascular complications have been performed. Several but not all studies have provided evidence to support the beneficial effects of incretin-based therapies on diabetic complications in patients with type 2 diabetes. We herein discuss the experimental and clinical evidence of incretin-based therapy for diabetic complications.


Subject(s)
Diabetes Complications/drug therapy , Dipeptidyl-Peptidase IV Inhibitors/therapeutic use , Glucagon-Like Peptide-1 Receptor/agonists , Hypoglycemic Agents/therapeutic use , Incretins/therapeutic use , Humans
12.
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
13.
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
14.
Commun Biol ; 7(1): 402, 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38565675

ABSTRACT

Focal segmental glomerulosclerosis (FSGS) shares podocyte damage as an essential pathological finding. Several mechanisms underlying podocyte injury have been proposed, but many important questions remain. Rho-associated, coiled-coil-containing protein kinase 2 (ROCK2) is a serine/threonine kinase responsible for a wide array of cellular functions. We found that ROCK2 is activated in podocytes of adriamycin (ADR)-induced FSGS mice and cultured podocytes stimulated with ADR. Conditional knockout mice in which the ROCK2 gene was selectively disrupted in podocytes (PR2KO) were resistant to albuminuria, glomerular sclerosis, and podocyte damage induced by ADR injection. In addition, pharmacological intervention for ROCK2 significantly ameliorated podocyte loss and kidney sclerosis in a murine model of FSGS by abrogating profibrotic factors. RNA sequencing of podocytes treated with a ROCK2 inhibitor proved that ROCK2 is a cyclic nucleotide signaling pathway regulator. Our study highlights the potential utility of ROCK2 inhibition as a therapeutic option for FSGS.


Subject(s)
Glomerulosclerosis, Focal Segmental , Podocytes , Animals , Mice , Doxorubicin/pharmacology , Glomerulosclerosis, Focal Segmental/genetics , Glomerulosclerosis, Focal Segmental/prevention & control , Mice, Knockout , Podocytes/metabolism , Protein Serine-Threonine Kinases/metabolism , Sclerosis/metabolism , Sclerosis/pathology
15.
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
16.
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
17.
Methods Mol Biol ; 2419: 475-479, 2022.
Article in English | MEDLINE | ID: mdl-35237982

ABSTRACT

Transendothelial leukocyte migration is an early event in the progression of vascular inflammation, the underlying molecular mechanism of atherosclerosis. Inflammatory mediators such as adhesion molecules and chemokines are essential in this process. Leukocyte migration into the vascular wall can be monitored by the detection of CD11b-positive immune cells in animal models of atherosclerosis. This chapter will describe an immunohistochemical technique used to evaluate leukocyte migration in vivo.


Subject(s)
Atherosclerosis , Animals , Cell Adhesion , Cell Adhesion Molecules , Cell Movement , Chemokines , Inflammation , Leukocytes
18.
Commun Biol ; 5(1): 341, 2022 04 08.
Article in English | MEDLINE | ID: mdl-35396346

ABSTRACT

Loss of podocytes is a common feature of diabetic renal injury and a key contributor to the development of albuminuria. We found that podocyte Rho associated coiled-coil containing protein kinase 2 (ROCK2) is activated in rodent models and patients with diabetes. Mice that lacked ROCK2 only in podocytes (PR2KO) were resistant to albuminuria, glomerular fibrosis, and podocyte loss in multiple animal models of diabetes (i.e., streptozotocin injection, db/db, and high-fat diet feeding). RNA-sequencing of ROCK2-null podocytes provided initial evidence suggesting ROCK2 as a regulator of cellular metabolism. In particular, ROCK2 serves as a suppressor of peroxisome proliferator-activated receptors α (PPARα), which rewires cellular programs to negatively control the transcription of genes involved in fatty acid oxidation and consequently induce podocyte apoptosis. These data establish ROCK2 as a nodal regulator of podocyte energy homeostasis and suggest this signaling pathway as a promising target for the treatment of diabetic podocytopathy.


Subject(s)
Diabetes Mellitus, Experimental , Diabetic Nephropathies , Podocytes , Albuminuria/metabolism , Animals , Diabetes Mellitus, Experimental/metabolism , Diabetic Nephropathies/genetics , Diabetic Nephropathies/metabolism , Humans , Mice , Podocytes/metabolism , Streptozocin/adverse effects , Streptozocin/metabolism , rho-Associated Kinases/genetics , rho-Associated Kinases/metabolism
19.
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
20.
Front Pharmacol ; 12: 738121, 2021.
Article in English | MEDLINE | ID: mdl-34557101

ABSTRACT

Rho-associated coiled-coil-containing protein kinase (ROCK) is a serine/threonine kinase with essential roles in cytoskeletal functions. Substantial evidence implicates ROCK as a critical regulator in the inception and progression of diabetic nephropathy through a mechanism involving mesangial fibrosis, podocyte apoptosis, and endothelial inflammation. Despite these experimental observations, human data is lacking. Here we show that the phosphorylated form of myosin phosphatase targeting subunit 1 (MYPT1), a ROCK substrate, was increased in both the glomerular and tubulointerstitial areas in patients with histologically confirmed diabetic nephropathy. We also conducted a retrospective pilot analysis of data from patients with diabetes to assess the renoprotective effects of fasudil, an ATP-competitive ROCK inhibitor licensed in Japan for the prevention of vasospasm following subarachnoid hemorrhage. Fifteen subjects (male, n = 8; female, n = 7; age 65.7 ± 14.7 years; body height, 161.1 ± 12.6 cm; body weight, 57.6 ± 13.7 kg; body mass index, 22.4 ± 3.7 kg/m2) were enrolled to evaluate blood pressure and the renal outcome after fasudil treatment. Of note, proteinuria was significantly reduced at the end of the fasudil treatment without affecting the blood pressure or estimated glomerular filtration rate. Taken together, these findings suggest that the administration of fasudil could be associated with a better renal outcome by inhibiting the ROCK activity in patients with diabetes.

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