Mechanosensitive cation channel Piezo1 contributes to ventilator-induced lung injury by activating RhoA/ROCK1 in rats.

BACKGROUND: Mechanical ventilation can induce or aggravate lung injury, which is termed ventilator-induced lung injury (VILI). Piezo1 is a key element of the mechanotransduction process and can transduce mechanical signals into biological signals by mediating Ca2+ influx, which in turn regulates cytoskeletal remodeling and stress alterations. We hypothesized that it plays an important role in the occurrence of VILI, and investigated the underlying mechanisms. METHODS: High tidal volume mechanical ventilation and high magnitude cyclic stretch were performed on Sprague-Dawley rats, and A549 and human pulmonary microvascular endothelial cells, respectively, to establish VILI models. Immunohistochemical staining, flow cytometry, histological examination, enzyme-linked immunosorbent assay, western blotting, quantitative real-time polymerase chain reaction and survival curves were used to assess the effect of Piezo1 on induction of lung injury, as well as the signaling pathways involved. RESULTS: We observed that Piezo1 expression increased in the lungs after high tidal volume mechanical ventilation and in cyclic stretch-treated cells. Mechanistically, we observed the enhanced expression of RhoA/ROCK1 in both cyclic stretch and Yoda1-treated cells, while the deficiency or inhibition of Piezo1 dramatically antagonized RhoA/ROCK1 expression. Furthermore, blockade of RhoA/ROCK1 signaling using an inhibitor did not affect Piezo1 expression. GSMTx4 was used to inhibit Piezo1, which alleviated VILI-induced pathologic changes, water content and protein leakage in the lungs, and the induction of systemic inflammatory mediators, and improved the 7-day mortality rate in the model rats. CONCLUSIONS: These findings indicate that Piezo1 affects the development and progression of VILI through promotion of RhoA/ROCK1 signaling.

Circ_PIP5K1A regulates cisplatin resistance and malignant progression in non-small cell lung cancer cells and xenograft murine model via depending on miR-493-5p/ROCK1 axis.

BACKGROUND: Chemoresistance limits the therapeutic effect of cisplatin (DDP) on non-small cell lung cancer (NSCLC). Circular RNAs (circRNAs) function as important regulators in chemoresistance. This study aimed to explore the regulation of circRNA Phosphatidylinositol-4-Phosphate 5-Kinase Type 1 Alpha (circ_PIP5K1A) in DDP resistance. METHODS: The expression analysis of circ_PIP5K1A, micoRNA-493-5p (miR-493-5p) and Rho Associated Coiled-Coil Containing Protein Kinase 1 (ROCK1) was conducted through reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Cell sensitivity was determined using 3-(4,5-dimethylthiazol-2-y1)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cell proliferation and cell viability were evaluated by colony formation assay and MTT assay, respectively. Cell cycle and apoptosis detection was performed via flow cytometry. Cell motility was examined by transwell migration or invasion assay. Dual-luciferase reporter assay was applied to confirm the target binding. ROCK1 protein level was assayed via Western blot. In vivo assay was carried out using xenograft model in mice. RESULTS: Circ_PIP5K1A level was abnormally increased in DDP-resistant NSCLC tissues and cells. Silencing circ_PIP5K1A reduced DDP resistance, proliferation, cell cycle progression and cell motility in DDP-resistant NSCLC cells. Circ_PIP5K1A directly interacted with miR-493-5p in NSCLC cells. The function of circ_PIP5K1A was dependent on the negative regulation of miR-493-5p. MiR-493-5p directly targeted ROCK1 and circ_PIP5K1A regulated the ROCK1 level via acting as a sponge of miR-493-5p. Overexpression of miR-493-5p inhibited chemoresistance and cancer progression by downregulating ROCK1 expression in DDP-resistant NSCLC cells. Circ_PIP5K1A regulated DDP sensitivity in vivo via the miR-493-5p/ROCK1 axis. CONCLUSION: These findings suggested that circ_PIP5K1A upregulated the ROCK1 expression to promote DDP resistance and cancer progression in NSCLC by sponging miR-493-5p.

Curcumin reinforces MSC-derived exosomes in attenuating osteoarthritis via modulating the miR-124/NF-kB and miR-143/ROCK1/TLR9 signalling pathways.

Curcumin treatment was reported to delay the progression of OA, but its underlying mechanism remains unclear. In this study, we aimed to investigate the molecular mechanism underlying the role of curcumin in OA treatment. Accordingly, by conducting MTT and flow cytometry assays, we found that the exosomes derived from curcumin-treated MSCs helped to maintain the viability while inhibiting the apoptosis of model OA cells. Additionally, quantitative real-time PCR and Western blot assays showed that the exosomes derived from curcumin-treated MSCs significantly restored the down-regulated miR-143 and miR-124 expression as well as up-regulated NF-kB and ROCK1 expression in OA cells. Mechanistically, curcumin treatment decreased the DNA methylation of miR-143 and miR-124 promoters. In addition, the 3' UTRs of NF-kB and ROCK1 were proven to contain the binding sites for miR-143 and miR-124, respectively. Therefore, the up-regulation of miR-143 and miR-124 in cellular and mouse OA models treated with exosomes remarkably restored the normal expression of NF-kB and ROCK1. Consequently, the progression of OA was attenuated by the exosomes. Our results clarified the molecular mechanism underlying the therapeutic role of MSC-derived exosomes in OA treatment.

RhoA/ROCK pathway mediates the effect of oestrogen on regulating epithelial-mesenchymal transition and proliferation in endometriosis.

Endometriosis is a benign gynaecological disease appearing with pelvic pain, rising dysmenorrhoea and infertility seriously impacting on 10% of reproductive-age females. This research attempts to demonstrate the function and molecular mechanism of RhoA/ROCK pathway on epithelial-mesenchymal transition (EMT) and proliferation in endometriosis. The expression of Rho family was abnormally changed in endometriotic lesions; in particular, RhoA and ROCK1/2 were significantly elevated. Overexpression of RhoA in human eutopic endometrial epithelial cells (eutopic EECs) enhanced the cell mobility, epithelial-mesenchymal transition (EMT) and proliferation, and RhoA knockdown exhibited the opposite function. Oestrogen up-regulated the RhoA activity and expression of RhoA and ROCK1/2. RhoA overexpression reinforced the effect of oestrogen on promoting EMT and proliferation, and RhoA knockdown impaired the effect of oestrogen. oestrogen receptor α (ERα) was involved with the regulation of oestrogen on EMT and proliferation and up-regulated RhoA activity and expression of RhoA and ROCK1/2. The function of ERα was modulated by the change in RhoA expression. Furthermore, phosphorylated ERK that was enhanced by oestrogen and ERα promoted the protein expression of RhoA/ROCK pathway. Endometriosis mouse model revealed that oestrogen enhanced the size and weight of endometriotic lesions. The expression of RhoA and phosphorylated ERK in mouse endometriotic lesions was significantly elevated by oestrogen. We conclude that abnormal activated RhoA/ROCK pathway in endometriosis is responsible for the function of oestrogen/ERα/ERK signalling, which promoted EMT and proliferation and resulted in the development of endometriosis.

miR-335-5p inhibits TGF-ß1-induced epithelial-mesenchymal transition in non-small cell lung cancer via ROCK1.

BACKGROUND: Significant evidence has shown that the miRNA pathway is an important component in the downstream signaling cascades of TGF-ß1 pathway. Our previous study has indicated that miR-335-5p expression was significantly down-regulated and acted as a vital player in the metastasis of non-small cell lung cancer (NSCLC), however the underlying mechanism remained unclear. METHODS: The differential expression level of miR-335-5p and ROCK1 were determined by qRT-PCR and IHC analysis in human tissue samples with or without lymph node metastasis. Transwell assay was conducted to determine cell ability of migration and invasion. SiRNA interference, microRNA transfection and western blot analysis were utilized to clarify the underlying regulatory mechanism. RESULTS: We showed that down-regulated expression of miR-335-5p and up-regulated expression of ROCK1 in NSCLC tissues were associated with lymph node metastasis. Over-expresion of miR-335-5p significantly inhibited TGF-ß1-mediated NSCLC migration and invasion. Furthermore, luciferase reporter assays proved that miR-335-5p can bind to 3'-UTR of ROCK1 directly. Moreover, we confirmed that siRNA-mediated silencing of ROCK1 significantly diminished TGF-ß1-mediated EMT and migratory and invasive capabilities of A549 and SPC-A1 cells. CONCLUSION: This is the first time to report that miR-335-5p regulates ROCK1 and impairs its functions, thereby playing a key role in TGF-ß1-induced EMT and cell migration and invasion in NSCLC.

TGF-ß Stimulates Expression of Chondroitin Polymerizing Factor in Nucleus Pulposus Cells Through the Smad3, RhoA/ROCK1, and MAPK Signaling Pathways.

The enzyme chondroitin polymerizing factor (ChPF) is primarily involved in extension of the chondroitin sulfate backbone required for the synthesis of sulfated glycosaminoglycan (sGAG). Transforming growth factor beta (TGF-ß) upregulates sGAG synthesis in nucleus pulposus cells; however, the mechanisms mediating this induction are incompletely understood. Our study demonstrated that ChPF expression was negatively correlated with the grade of degenerative intervertebral disc disease. Treatment of nucleus pulposus cells with TGF-ß induced ChPF expression and enhanced Smad2/3, RhoA/ROCK activation, and the JNK, p38, and ERK1/2 MAPK signaling pathways. Selective inhibitors of Smad2/3, RhoA or ROCK1/2, and knockdown of Smad3 and ROCK1 attenuated ChPF expression and sGAG synthesis induced by TGF-ß. In addition, we showed that RhoA/ROCK1 signaling upregulated ChPF via activation of the JNK pathway but not the p38 and ERK1/2 signaling pathways. Moreover, inhibitors of JNK, p38 and ERK1/2 activity also blocked ChPF expression and sGAG synthesis induced by TGF-ß in a Smad3-independent manner. Collectively, our data suggest that TGF-ß stimulated the expression of ChPF and sGAG synthesis in nucleus pulposus cells through Smad3, RhoA/ROCK1 and the three MAPK signaling pathways. J. Cell. Biochem. 119: 566-579, 2018. © 2017 Wiley Periodicals, Inc.

Long non-coding RNA NEAT1 promoted ovarian cancer cells' metastasis through regulation of miR-382-3p/ROCK1 axial.

Long non-coding RNA (lncRNA) are extensively involved in various malignant tumors, including ovarian cancer (OC). In the present study, we focused on the expression and function of nuclear enriched abundant transcript 1 (NEAT1) in OC cells' metastasis. We demonstrated that NEAT1 was upregulated in OC tissue specimens and cell lines. In addition, we revealed that depression of NEAT1 inhibited OC cells' metastasis and the expression of Rho associated coiled-coil containing protein kinase 1 (ROCK1), which is a metastasis-related gene. Using online predictive software and a series of luciferase assays, we demonstrated that both NEAT1 and ROCK1 were the targets of microRNA-382-3p (miR-382-3p) and share similar microRNA responding elements (MRE). Furthermore, we illustrated that NEAT1 and miR-382-3p inhibited each other in a reciprocal manner. Finally, through antisense experiments we demonstrated that NEAT1 promoted ROCK1-mediated metastasis by functioning as a ceRNA of miR-382-3p. In summary, the findings of this study revealed that NEAT1 promoted OC cells' metastasis through regulating the miR-382-3p/ROCK1 axial. The present study might provide a new target for treating OC.

The shift in GH3 cell shape and cell motility is dependent on MLCK and ROCK.

Cytoskeletal organization, actin-myosin contractility and the cell membrane together regulate cell morphology in response to the cell environment, wherein the extracellular matrix (ECM) is an indispensable component. Plasticity in cell shape enables cells to adapt their migration mode to their surroundings. GH3 endocrine cells respond to different ECM proteins, acquiring different morphologies: a rounded on collagen I-III (C I-III) and an elongated on collagen IV (C IV). However, the identities of the molecules that participate in these responses remain unknown. Considering that actin-myosin contractility is crucial to maintaining cell shape, we analyzed the participation of MLCK and ROCK in the acquisition of cell shape, the generation of cellular tension and the cell motility mode. We found that a rounded shape with high cortical tension depends on MLCK and ROCK, whereas in cells with an elongated shape, MLCK is the primary protein responsible for cell spreading. Further, in cells with a slow and directionally persistent motility, MLCK predominates, while rapid and erratic movement is ROCK-dependent. This behavior also correlates with GTPase activation. Cells on C I-III exhibited higher Rho-GTPase activity than cells on C IV and vice versa with Rac-GTPase activity, showing a plastic response of GH3 cells to their environment, leading to the generation of different cytoskeleton and membrane organizations and resulting in two movement strategies, rounded and fibroblastoid-like.

Systemic delivery of microRNA-101 potently inhibits hepatocellular carcinoma in vivo by repressing multiple targets.

Targeted therapy based on adjustment of microRNA (miRNA)s activity takes great promise due to the ability of these small RNAs to modulate cellular behavior. However, the efficacy of miR-101 replacement therapy to hepatocellular carcinoma (HCC) remains unclear. In the current study, we first observed that plasma levels of miR-101 were significantly lower in distant metastatic HCC patients than in HCCs without distant metastasis, and down-regulation of plasma miR-101 predicted a worse disease-free survival (DFS, P<0.05). In an animal model of HCC, we demonstrated that systemic delivery of lentivirus-mediated miR-101 abrogated HCC growth in the liver, intrahepatic metastasis and distant metastasis to the lung and to the mediastinum, resulting in a dramatic suppression of HCC development and metastasis in mice without toxicity and extending life expectancy. Furthermore, enforced overexpression of miR-101 in HCC cells not only decreased EZH2, COX2 and STMN1, but also directly down-regulated a novel target ROCK2, inhibited Rho/Rac GTPase activation, and blocked HCC cells epithelial-mesenchymal transition (EMT) and angiogenesis, inducing a strong abrogation of HCC tumorigenesis and aggressiveness both in vitro and in vivo. These results provide proof-of-concept support for systemic delivery of lentivirus-mediated miR-101 as a powerful anti-HCC therapeutic modality by repressing multiple molecular targets.

Expression of Rho Kinase and Its Mechanism in the Left Atrial Appendage in Patients with Atrial Fibrillation.

AIM: To study the expression of Rho kinase (Rho associated coil forming protein kinase-1, ROCK-1) and its substrate myosin phosphatase target subunit 1 (myosin phosphatase target subunit-1, MYPT-1), connexin 40 (Cx40) and connexin 43 (Cx43) in the left atrial appendage of patients with atrial fibrillation, and explore the role of ROCK signaling pathway in patients with atrial fibrillation and its underlying mechanism. Methods: 40 patients undergoing open heart surgery were divided into two groups; atrial fibrillation group (AF group) and sinus rhythm group (SR group). About 100 mg of left atrial appendage tissue was taken during surgery and quickly frozen in liquid nitrogen. Immunohistochemistry and western blot were performed to evaluate the expression and location of ROCK-1, MYPT-1, Cx40 and Cx43 in the left atrial appendage tissue. Results: The results indicated that the expression of ROCK-1, MYPT-1, and Cx40 in the left atrial appendage in patients with atrial fibrillation was significantly upregulated (P < .01), the difference in the two groups was statistically significant, and ROCK-1, Cx40, and MYPT-1 expression in the AF group were higher than those in sinus rhythm group; there was a weakly positive expression of Cx43 protein in the AF group and sinus rhythm group, the difference was not statistically significant, and ROCK-1 and MYPT-1 expression showed a significant positive correlation (r = 0.968, P < .05), MYPT 1 and Cx40 protein expression was also positively correlated (r = 0.983, P < .05). Evidence in the left atrial appendage tissue of patients with atrial fibrillation showed that some proteins in Rho/ROCK pathway were upregulated, and MYPT-1 and Cx40 protein expression in AF group were significantly higher than that of SR group, which was also positively correlated; Cx43 showed a weak positive expression in both the SR group and AF group, which indicates that Rho kinase may induce expression of Cx40 by phosphorylation of MYPT-1; Cx43 may not be involved, suggesting that Rho kinase signaling pathway may activate and play an important role in the pathogenesis of atrial fibrillation lesions.

Long non-coding RNA NEAT1 regulates the proliferation, migration and invasion of gastric cancer cells via targeting miR-335-5p/ROCK1 axis.

This study aimed to elucidate the roles of long non-coding RNA Nuclear Paraspeckle Assembly Transcript 1 (NEAT1) in gastric cancer. The expression of NEAT1 in gastric cancer tissues and cells was determined. NEAT1 was then overexpressed and suppressed in BGC-823 cells in vitro to further explore the effects of NEAT1 on cell proliferation, migration, and invasion. In addition, the regulatory relationship among NEAT1, miR-335-5p and Rho Associated Coiled-Coil Containing Protein Kinase 1 (ROCK1) was investigated. LncRNA NEAT1 was upregulated in gastric cancer tissues and cells. Upregulated NEAT1 significantly promoted the proliferation, migration and invasion of BGC-823 cells, while suppression of NEAT1 exhibited contrary results. In addition, lncRNA NEAT1 inhibited the expression of miR-335-5p, and miR-335-5p targeted ROCK1 in BGC-823 cells. miR-335-5p overexpression significantly inhibited cell proliferation, migration and invasion, which was counteracted by ROCK1 overexpression concurrently. Our findings indicate that upregulation of NEAT1 may promote proliferation, migration and invasion of gastric cancer cells via targeting miR-335-5p/ROCK1 axis. NEAT1-miR-335-5p-ROCK1 axis may be a potential therapeutic strategy for gastric cancer therapy.

ROCK1/p53/NOXA signaling mediates cardiomyocyte apoptosis in response to high glucose in vitro and vivo.

Gestational diabetes mellitus is a risk factor for congenital heart defects; however, the molecular basis of the congenital heart anomalies remains obscure. Previous reports showed a positive correlation between abnormal cardiomyocyte apoptosis and ventricular wall thinness, one type of congenital heart anomaly. This work explored the expression pattern and molecular mechanism of the Rho-associated coiled-coil containing protein kinase 1 (ROCK1) gene in cardiomyocyte apoptosis and genesis of ventricular wall thinness. In this report, we found a marked increase in the number of apoptotic cardiomyocytes in response to high glucose (HG) treatment. Moreover, up-regulation of ROCK1 expression observed in diabetic offspring compared with controls was potentially associated with cardiomyocyte apoptosis and the ventricular wall thinness. Further investigation showed that p53 and NOXA protein levels increased during ROCK1-meidated apoptosis in response to HG. In response to HG, whereby ROCK1 phosphorylated p53 at Ser15 to up-regulate its protein level. Furthermore, we found that p53 mediated the expression of NOXA during HG-induced apoptosis, and histone acetyltransferase p300 participated in this process. These findings reveal a novel regulatory mechanism of ROCK1/p53/NOXA signaling in modulating cardiomyocyte apoptosis in vitro and maternal diabetes-induced congenital heart defects in vivo.

RhoA/ROCK pathway inhibition by fasudil suppresses the vasculogenic mimicry of U2OS osteosarcoma cells in vitro.

GTPase RhoA and its downstream Rho-associated coiled-coil-containing protein kinases (ROCKs) are frequently overexpressed in human cancers. Inhibition of the RhoA/ROCK pathway blocks angiogenesis mediated by the vascular endothelial growth factor, which led us to investigate the role of this pathway in vasculogenic mimicry (VM) - a process by which aggressive cancer cells form vessel-like structures that provide adequate blood supply for tumor growth. We showed that the expression of RhoA and its effector kinases ROCK1/2 was much higher in human osteosarcoma (OS) tissues and the human OS cell line U2OS than in nontumorous tissues and cell line hFOB 1.19 using western blot analysis and real-time PCR. Inhibition of the RhoA/ROCK signaling pathway by the pharmacological inhibitor fasudil reduced vascular-like channels of U2OS cells in Matrigel. Furthermore, we used rhodamine-phalloidin immunofluorescence, wound healing assay, and transwell migration assay to examine the effect of fasudil on tumor cell plasticity and motility, both of which play key roles in VM formation. Finally, we explored the underlying mechanisms of fasudil-induced VM destruction. In this context, we showed that the RhoA/ROCK signaling pathway is a novel regulator in VM of U2OS OS cells and suggest that fasudil in conjunction with established treatments may present a novel therapeutic strategy for OS.

Tissue-selective expression of a conditionally-active ROCK2-estrogen receptor fusion protein.

The serine/threonine kinases ROCK1 and ROCK2 are central mediators of actomyosin contractile force generation that act downstream of the RhoA small GTP-binding protein. As a result, they have key roles in regulating cell morphology and proliferation, and have been implicated in numerous pathological conditions and diseases including hypertension and cancer. Here we describe the generation of a gene-targeted mouse line that enables CRE-inducible expression of a conditionally-active fusion between the ROCK2 kinase domain and the hormone-binding domain of a mutated estrogen receptor (ROCK2:ER). This two-stage system of regulation allows for tissue-selective expression of the ROCK2:ER fusion protein, which then requires administration of estrogen analogues such as tamoxifen or 4-hydroxytamoxifen to elicit kinase activity. This conditional gain-of-function system was validated in multiple tissues by crossing with mice expressing CRE recombinase under the transcriptional control of cytokeratin14 (K14), murine mammary tumor virus (MMTV) or cytochrome P450 Cyp1A1 (Ah) promoters, driving appropriate expression in the epidermis, mammary or intestinal epithelia respectively. Given the interest in ROCK signaling in normal physiology and disease, this mouse line will facilitate research into the consequences of ROCK activation that could be used to complement conditional knockout models. Birth Defects Research (Part A) 106:636-646, 2016. © 2016 Wiley Periodicals, Inc.

MiR-145 suppresses cell proliferation and motility by inhibiting ROCK1 in hepatocellular carcinoma.

MicroRNAs (miRNAs) play key roles in cancer development and progression. In the present study, we investigated the role of miR-145 in the progression of hepatocellular carcinoma (HCC). Ten HCC cell lines and samples from 96 patients with HCC were analyzed for the expression of miR-145 by quantitative real-time polymerase chain reaction (qRT-PCR). Overexpression of miR-145 was established by transfecting mimics into HepG2 and QGY-7703 cells. Cell proliferation and cell migration were assessed by cell viability assay and transwell assay. Western blot was to verify ROCK1 as a novel target gene of miR-145. Our results showed that miR-145 was frequently downregulated in HCC tumors and cell lines. Overexpression of miR-145 in HCC cell lines significantly inhibited cell proliferation, migration, and invasion in vitro. ROCK1 was identified as a target of miR-145, and ectopic expression of miR-145 downregulated ROCK1. Together, these findings indicate that miR-145 acts as a tumor suppressor and its downregulation in tumor tissues may contribute to the progression and metastasis of HCC through a mechanism involving ROCK1, suggesting miR-145 as a potential new diagnostic and therapeutic target for the treatment of HCC.

RhoA/rock signaling mediates peroxynitrite-induced functional impairment of Rat coronary vessels.

BACKGROUND: Diabetes-induced vascular dysfunction may arise from reduced nitric oxide (NO) availability, following interaction with superoxide to form peroxynitrite. Peroxynitrite can induce formation of 3-nitrotyrosine-modified proteins. RhoA/ROCK signaling is also involved in diabetes-induced vascular dysfunction. The study aimed to investigate possible links between Rho/ROCK signaling, hyperglycemia, and peroxynitrite in small coronary arteries. METHODS: Rat small coronary arteries were exposed to normal (NG; 5.5 mM) or high (HG; 23 mM) D-glucose. Vascular ring constriction to 3 mM 4-aminopyridine and dilation to 1 µM forskolin were measured. Protein expression (immunohistochemistry and western blot), mRNA expression (real-time PCR), and protein activity (luminescence-based G-LISA and kinase activity spectroscopy assays) of RhoA, ROCK1, and ROCK2 were determined. RESULTS: Vascular ring constriction and dilation were smaller in the HG group than in the NG group (P < 0.05); inhibition of RhoA or ROCK partially reversed the effects of HG. Peroxynitrite impaired vascular ring constriction/dilation; this was partially reversed by inhibition of RhoA or ROCK. Protein and mRNA expressions of RhoA, ROCK1, and ROCK2 were higher under HG than NG (P < 0.05). This HG-induced upregulation was attenuated by inhibition of RhoA or ROCK (P < 0.05). HG increased RhoA, ROCK1, and ROCK2 activity (P < 0.05). Peroxynitrite also enhanced RhoA, ROCK1, and ROCK2 activity; these actions were partially inhibited by 100 µM urate (peroxynitrite scavenger). Exogenous peroxynitrite had no effect on the expression of the voltage-dependent K+ channels 1.2 and 1.5. CONCLUSIONS: Peroxynitrite-induced coronary vascular dysfunction may be mediated, at least in part, through increased expressions and activities of RhoA, ROCK1, and ROCK2.

ROCK insufficiency attenuates ozone-induced airway hyperresponsiveness in mice.

Ozone causes airway hyperresponsiveness (AHR) and pulmonary inflammation. Rho kinase (ROCK) is a key regulator of smooth muscle cell contraction and inflammatory cell migration. To determine the contribution of the two ROCK isoforms ROCK1 and ROCK2 to ozone-induced AHR, we exposed wild-type, ROCK1(+/-), and ROCK2(+/-) mice to air or ozone (2 ppm for 3 h) and evaluated mice 24 h later. ROCK1 or ROCK2 haploinsufficiency did not affect airway responsiveness in air-exposed mice but significantly reduced ozone-induced AHR, with a greater reduction in ROCK2(+/-) mice despite increased bronchoalveolar lavage (BAL) inflammatory cells in ROCK2(+/-) mice. Compared with wild-type mice, ozone-induced increases in BAL hyaluronan, a matrix protein implicated in ozone-induced AHR, were lower in ROCK1(+/-) but not ROCK2(+/-) mice. Ozone-induced increases in other inflammatory moieties reported to contribute to ozone-induced AHR (IL-17A, osteopontin, TNFα) were not different in wild-type vs. ROCK1(+/-) or ROCK2(+/-) mice. We also observed a dose-dependent reduction in ozone-induced AHR after treatment with the ROCK1/ROCK2 inhibitor fasudil, even though fasudil was administered after induction of inflammation. Ozone increased pulmonary expression of ROCK2 but not ROCK1 or RhoA. A ROCK2 inhibitor, SR3677, reduced contractile forces in primary human airway smooth muscle cells, confirming a role for ROCK2 in airway smooth muscle contraction. Our results demonstrate that ozone-induced AHR requires ROCK. Whereas ROCK1-dependent changes in hyaluronan may contribute to ROCK1's role in O3-induced AHR, the role of ROCK2 is downstream of inflammation, likely at the level of airway smooth muscle contraction.

AAV-mediated expression of BAG1 and ROCK2-shRNA promote neuronal survival and axonal sprouting in a rat model of rubrospinal tract injury.

A lesion to the rat rubrospinal tract is a model for traumatic spinal cord lesions and results in atrophy of the red nucleus neurons, axonal dieback, and locomotor deficits. In this study, we used adeno-associated virus (AAV)-mediated over-expression of BAG1 and ROCK2-shRNA in the red nucleus to trace [by co-expression of enhanced green fluorescent protein (EGFP)] and treat the rubrospinal tract after unilateral dorsal hemisection. We investigated the effects of targeted gene therapy on neuronal survival, axonal sprouting of the rubrospinal tract, and motor recovery 12 weeks after unilateral dorsal hemisection at Th8 in rats. In addition to the evaluation of BAG1 and ROCK2 as therapeutic targets in spinal cord injury, we aimed to demonstrate the feasibility and the limits of an AAV-mediated protein over-expression versus AAV.shRNA-mediated down-regulation in this traumatic CNS lesion model. Our results demonstrate that BAG1 and ROCK2-shRNA both promote neuronal survival of red nucleus neurons and enhance axonal sprouting proximal to the lesion.

MiR-335 acts as a potential tumor suppressor miRNA via downregulating ROCK1 expression in hepatocellular carcinoma.

Increasing evidence has suggested that dysregulation of microRNAs (miRNAs) could contribute to tumor progression. Previous miRNA microarray analysis illustrated that miR-335 is downregulated in various cancers; however, the role of miR-335 on hepatocellular carcinoma (HCC) has not been well elucidated. In this study, we investigated the biological functions and molecular mechanisms of miR-335 in human HCC in vitro, discussing whether it could be a therapeutic biomarker of HCC in the future. Four HCC cell lines and samples from 62 patients with HCC were analyzed for the expression of miR-335 by quantitative RT-PCR. Overexpression of miR-335 was established by transfecting mimics into HepG2 and HuH7 cells. Cell proliferation and cell migration were assessed by cell viability assay and transwell assay. Luciferase reporter assay and Western blot were to verify ROCK1 as a novel target gene of miR-335. We observed that miR-335 was downregulated in human HCC tissues and in all four HCC cell lines. The MTT assay revealed that overexpression of miR-335 subsequently inhibited cell growth. Furthermore, the transwell assay also showed significant cell migration inhibition in miR-335 transfectant. The expression of ROCK1 was decreased evidently after overexpression of miR-335, indicating that ROCK1 is a target gene for miR-335. Our data revealed that miR-335 could inhibit the proliferation and migration invasion of HCC cells via regulating ROCK1, suggesting that miR-335 could be a therapeutic biomarker of HCC in the future.

Fasudil prevents calcium oxalate crystal deposit and renal fibrogenesis in glyoxylate-induced nephrolithic mice.

Nephrolithiasis is a common kidney disease and one of the major causes of chronic renal insufficiency. We develop and utilize a glyoxylate induced mouse model of kidney calcium oxalate crystal deposition for studying the pharmacological effects of fasudil, a Rho associated protein kinase (ROCK) specific inhibitor, on the kidney injury and fibrosis caused by calcium oxalate crystallization and deposition. Glyoxylate was administrated intraperitoneally to C57BL/6J mice for five consecutive days to establish a mouse model of kidney calcium oxalate crystal formation and deposition. The results showed that the protein expression levels of E-cad and Pan-ck were lower, and the protein expression levels of α-SMA and Vim were higher, in the kidney tissue of the glyoxylate induced model mice compared with the control mice. The changes in protein expression were weakened when the animals were pretreated with fasudil before glyoxylate administration. Expression of ROCK, PAI-1, and p-Smad proteins in the kidney tissue increased in response to glyoxylate treatment, and the increase was eased when the animals were pretreated with fasudil. Expression of Smad2 and Smad3 in the kidney tissue remained unchanged after glyoxylate administration. Cell apoptosis and proliferation in the kidney cortex and medulla were enhanced in response to the glyoxylate induced calcium oxalate crystal formation and deposition, and fasudil pre-treatment was able to attenuate the enhancement. The results suggest that Fasudil reduces the glyoxylate induced kidney calcium crystal formation and deposition and slows down the kidney fibrogenesis caused by calcium crystal deposition. The possible mechanism may be related the regulatory effects on Rho/ROCK signal transduction and epithelial-mesenchymal transition (EMT).