Rho-associated, coiled-coil-containing protein kinase 2 regulates expression of mineralocorticoid receptor to mediate sodium reabsorption in mice.

The mineralocorticoid receptor (MR) is a member of the nuclear receptor family that was initially identified to regulate blood pressure through its ability to modulate kidney sodium handling in response to aldosterone. MR can be regulated by signals other than aldosterone; however, the detailed mechanisms remain to be elucidated. We found that MR is controlled in a Rho-associated coiled-coil-containing protein kinase 2 (ROCK2)-dependent manner. Mice with a specific deletion of ROCK2 in the kidney tubules showed decreased MR expression levels and increased urinary excretion of sodium. Mechanistically, signal transducer and activator of transcription 3 (STAT3) is a key molecule that mediates MR expression in these mice. This study highlights an important role of tubular ROCK2 in electrolyte homeostasis.

Deletion of podocyte Rho-associated, coiled-coil-containing protein kinase 2 protects mice from focal segmental glomerulosclerosis.

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.

Deciphering Rho-associated, coiled-coil-containing protein kinase in diabetic nephropathy: small steps towards a giant leap.

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.

Rho-kinase inhibitor restores glomerular fatty acid metabolism in diabetic kidney disease.

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.

Rho-associated, coiled-coil-containing protein kinase 1 regulates development of diabetic kidney disease via modulation of fatty acid metabolism.

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.

ROCK2-induced metabolic rewiring in diabetic podocytopathy.

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.

Monitoring Leukocyte Migration During Atherosclerosis In Vivo.

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.

Effects of individualized dietary advice compared with conventional dietary advice for adults with type 2 diabetes: A randomized controlled trial.

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.

Renal ROCK Activation and Its Pharmacological Inhibition in Patients With Diabetes.

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.

Correction: The thromboprotective effect of traditional Chinese medicine Tongji 2 granules is dependent on anti-inflammatory activity by suppression of NF-κB pathways.

[This corrects the article DOI: 10.1371/journal.pone.0241607.].

Myeloid Krüppel-like factor 2 is a critical regulator of metabolic inflammation.

Substantial evidence implicates crosstalk between metabolic tissues and the immune system in the inception and progression of obesity. However, molecular regulators that orchestrate metaflammation both centrally and peripherally remains incompletely understood. Here, we identify myeloid Krüppel-like factor 2 (KLF2) as an essential regulator of obesity and its sequelae. In mice and humans, consumption of a fatty diet downregulates myeloid KLF2 levels. Under basal conditions, myeloid-specific KLF2 knockout mice (K2KO) exhibit increased feeding and weight gain. High-fat diet (HFD) feeding further exacerbates the K2KO metabolic disease phenotype. Mechanistically, loss of myeloid KLF2 increases metaflammation in peripheral and central tissues. A combination of pair-feeding, bone marrow-transplant, and microglial ablation implicate central and peripheral contributions to K2KO-induced metabolic dysfunction observed. Finally, overexpression of myeloid KLF2 protects mice from HFD-induced obesity and insulin resistance. Together, these data establish myeloid KLF2 as a nodal regulator of central and peripheral metabolic inflammation in homeostasis and disease.

The thromboprotective effect of traditional Chinese medicine Tongji 2 granules is dependent on anti-inflammatory activity by suppression of NF-κB pathways.

Inflammation is a vital physiological response of the immune system meant to protect against the invasion of pathogens. However, accumulating evidence describes an intimate link between inflammation and thrombosis and cellular elements of the immune system of the immune system such as neutrophils and monocytes/macrophages are emerging as key players in the generation of a prothrombotic milieu suggesting that anti-inflammatory therapy may have a role in the management of thrombosis that is driven by inflammation. Tongji 2 (TJ2) is a traditional Chinese medication manufactured as granules by Tongji hospital of Tongji University (Shanghai, China) with known anti-inflammatory properties. In this study, we examine the effects of TJ2 on inflammation and thrombosis. Our study shows that TJ2 modulates NF-κB activation and thus generates a prominent anti-inflammatory effect. Further, we use mouse models of thrombosis to demonstrate that TJ2 has a beneficial effect in both arterial and venous thrombosis that occurs in the absence of alterations in platelet activation or coagulation.

ROCK Inhibition May Stop Diabetic Kidney Disease.

Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease and is strongly associated with cardiovascular mortality. Given the pandemic of obesity and diabetes, the elucidation of the molecular underpinnings of DKD and establishment of effective therapy are urgently required. Studies over the past decade have identified the activated renin-angiotensin system (RAS) and hemodynamic changes as important therapeutic targets. However, given the residual risk observed in patients treated with RAS inhibitors and/or sodium glucose co-transporter 2 inhibitors, the involvement of other molecular machinery is likely, and the elucidation of such pathways represents fertile ground for the development of novel strategies. Rho-kinase (ROCK) is a serine/threonine kinase that is under the control of small GTPase protein Rho. Many fundamental cellular processes, including migration, proliferation, and survival are orchestrated by ROCK through a mechanism involving cytoskeletal reorganization. From a pathological standpoint, several analyses provide compelling evidence supporting the hypothesis that ROCK is an important regulator of DKD that is highly pertinent to cardiovascular disease. In cell-based studies, ROCK is activated in response to a diverse array of external stimuli associated with diabetes, and renal ROCK activity is elevated in the context of type 1 and 2 diabetes. Experimental studies have demonstrated the efficacy of pharmacological or genetic inhibition of ROCK in the prevention of diabetes-related histological and functional abnormalities in the kidney. Through a bird's eye view of ROCK in renal biology, the present review provides a conceptual framework that may be widely applicable to the pathological processes of multiple organs and illustrate novel therapeutic promise in diabetology.

The Physiology, Pathology, and Therapeutic Interventions for ROCK Isoforms in Diabetic Kidney Disease.

Rho-associated coiled-coil-containing protein kinase (ROCK) is a serine/threonine kinase that was originally identified as RhoA interacting protein. A diverse array of cellular functions, including migration, proliferation, and phenotypic modulation, are orchestrated by ROCK through a mechanism involving cytoskeletal rearrangement. Mammalian cells express two ROCK isoforms: ROCK1 (Rho-kinase ß/ROKß) and ROCK2 (Rho-kinase α/ROKα). While both isoforms have structural similarities and are widely expressed across multiple tissues, investigations in gene knockout animals and cell-based studies have revealed distinct functions of ROCK1 and ROCK2. With respect to the kidney, inhibiting ROCK activity has proven effective for the preventing diabetic kidney disease (DKD) in both type 1 and type 2 diabetic rodent models. However, despite significant progress in the understanding of the renal ROCK biology over the past decade, the pathogenic roles of the ROCK isoforms is only beginning to be elucidated. Recent studies have demonstrated the involvement of renal ROCK1 in mitochondrial dynamics and cellular transdifferentiation, whereas ROCK2 activation leads to inflammation, fibrosis, and cell death in the diabetic kidney. This review provides a conceptual framework for dissecting the molecular underpinnings of ROCK-driven renal injury, focusing on the differences between ROCK1 and ROCK2.

Endothelial Dysfunction in Diabetes.

Diabetes is a worldwide health issue closely associated with cardiovascular events. Given the pandemic of obesity, the identification of the basic underpinnings of vascular disease is strongly needed. Emerging evidence has suggested that endothelial dysfunction is a critical step in the progression of atherosclerosis. However, how diabetes affects the endothelium is poorly understood. Experimental and clinical studies have illuminated the tight link between insulin resistance and endothelial dysfunction. In addition, macrophage polarization from M2 towards M1 contributes to the process of endothelial damage. The possibility that novel classes of anti-hyperglycemic agents exert beneficial effects on the endothelial function and macrophage polarization has been raised. In this review, we discuss the current status of knowledge regarding the pathological significance of insulin signaling in endothelium. Finally, we summarize recent therapeutic strategies against endothelial dysfunction with an emphasis on macrophage polarity.

Targeting Redox Imbalance as an Approach for Diabetic Kidney Disease.

Diabetic kidney disease (DKD) is a worldwide public health problem. It is the leading cause of end-stage renal disease and is associated with increased mortality from cardiovascular complications. The tight interactions between redox imbalance and the development of DKD are becoming increasingly evident. Numerous cascades, including the polyol and hexosamine pathways have been implicated in the oxidative stress of diabetes patients. However, the precise molecular mechanism by which oxidative stress affects the progression of DKD remains to be elucidated. Given the limited therapeutic options for DKD, it is essential to understand how oxidants and antioxidants are controlled in diabetes and how oxidative stress impacts the progression of renal damage. This review aims to provide an overview of the current status of knowledge regarding the pathological roles of oxidative stress in DKD. Finally, we summarize recent therapeutic approaches to preventing DKD with a focus on the anti-oxidative effects of newly developed anti-hyperglycemic agents.

Glycolaldehyde induces sensory neuron death through activation of the c-Jun N-terminal kinase and p-38 MAP kinase pathways.

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.

ROCK2 regulates TGF-ß-induced expression of CTGF and profibrotic genes via NF-κB and cytoskeleton dynamics in mesangial cells.

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.

Unraveling the Role of Inflammation in the Pathogenesis of Diabetic Kidney Disease.

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.

ROCK2 Regulates Monocyte Migration and Cell to Cell Adhesion in Vascular Endothelial Cells.

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.