Novel Insights into the Roles of Rho Kinase in Cancer

Rho-associated coiled-coil kinase (ROCK) is a major downstream effector of the small GTPase RhoA. The ROCK family, consisting of ROCK1 and ROCK2, plays a central role in the organization of the actin cytoskeleton, and is involved in a wide range of fundamental cellular functions such as contraction, adhesion, migration, proliferation, and apoptosis. Since the discovery of effective inhibitors such as fasudil and Y27632, the biological roles of ROCK have been extensively explored in numerous diseases, including cancer. Accumulating evidence supports the concept that ROCK plays important roles in tumor development and progression through regulating many key cellular functions associated with malignancy, including tumorigenicity, tumor growth, metastasis, angiogenesis, tumor cell apoptosis/survival and chemoresistance as well. This review focuses on the new advances of the most recent 5 years from the studies on the roles of ROCK in cancer development and progression; the discussion is mainly focused on the potential value of ROCK inhibitors in cancer therapy

Interferon-β-induced miR-155 inhibits osteoclast differentiation by targeting SOCS1 and MITF

AbstractIFN-β is induced via a c-fos dependent mechanism that is present downstream of the receptor activator of NF-κB ligand (RANKL)-RANK signal transduction cascade during osteoclast differentiation. Increased production of IFN-β in turn inhibits osteoclastogenesis. However, the mechanism by which IFN-β exerts its suppressive function remains unclear. In the present study, we found that miR-155, an IFN-β-induced miRNA, mediated the suppressive effect of IFN-β on osteoclast differentiation by targeting SOCS1 and MITF, two essential regulators of osteoclastogenesis. These findings have not only demonstrated that miR-155 inhibits osteoclast differentiation, but also provided a new therapeutic target for treatment of osteoclast-mediated diseases

Disruption of both ROCK1 and ROCK2 genes in cardiomyocytes promotes autophagy and reduces cardiac fibrosis during aging

In this study, we investigated the pathophysiological impact of Rho-associated coiled-coil–containing protein kinase (ROCK)1 and ROCK2 double deletion vs. single deletion on cardiac remodeling. Utilizing a cardiomyocyte-specific and tamoxifen-inducible MerCreMer recombinase (MCM), 3 mouse lines (MCM/ROCK1fl/fl/ROCK2fl/fl, MCM/ROCK1fl/fl, and MCM/ROCK2fl/fl) were generated. As early as 5 d after inducible deletion, the double ROCK knockout hearts exhibited reduced phosphorylation of myosin light chain (MLC) and focal adhesion kinase (FAK), supporting a role for ROCK activity in regulating the nonsarcomeric cytoskeleton. Moreover, the autophagy marker microtubule-associated proteins 1A-1B light chain 3B was increased in the double ROCK knockout, and these early molecular features persisted throughout aging. Mechanistically, the double ROCK knockout promoted age-associated or starvation-induced autophagy concomitant with reduced protein kinase B (AKT), mammalian target of rapamycin (mTOR), Unc-51–like kinase signaling, and cardiac fibrosis. In contrast, ROCK2 knockout hearts showed increased phosphorylated (p)-MLC and p-FAK levels, which were mostly attributable to a compensatory ROCK1 overactivation. Autophagy was inhibited at the baseline accompanying increased mTOR activity, leading to increased cardiac fibrosis in the ROCK2 knockout hearts. Finally, the loss of ROCK1 had no significant effect on p-MLC and p-FAK levels, mTOR signaling, or autophagy at baseline. In summary, deletions of ROCK isoforms in cardiomyocytes have different, even opposite, effects on endogenous ROCK activity and the MLC/FAK/AKT/mTOR signaling pathway, which is involved in autophagy and fibrosis of the heart

ROCK1 via LIM kinase regulates growth, maturation and actin based functions in mast cells

Understanding mast cell development is essential due to their critical role in regulating immunity and autoimmune diseases. Here, we show how Rho kinases (ROCK) regulate mast cell development and can function as therapeutic targets for treating allergic diseases. Rock1 deficiency results in delayed maturation of bone marrow derived mast cells (BMMCs) in response to IL-3 stimulation and reduced growth in response to stem cell factor (SCF) stimulation. Further, integrin-mediated adhesion and migration, and IgE-mediated degranulation are all impaired in Rock1-deficient BMMCs. To understand the mechanism behind altered mast cell development in Rock1-/- BMMCs, we analyzed the activation of ROCK and its downstream targets including LIM kinase (LIMK). We observed reduced activation of ROCK, LIMK, AKT and ERK1/2 in Rock1-deficient BMMCs in response to SCF stimulation. Further, loss of either Limk1 or Limk2 also demonstrated altered BMMC maturation and growth; combined deletion of both Limk1 and Limk2 resulted in further reduction in BMMC maturation and growth. In passive cutaneous anaphylaxis model, deficiency of Rock1 or treatment with ROCK inhibitor Fasudil protected mice against IgE-mediated challenge. Our results identify ROCK/LIMK pathway as a novel therapeutic target for treating allergic diseases involving mast cells

Viscosity and Thermal Conductivity of Stable Graphite Suspensions Near Percolation

Nanofluids have received much attention in part due to the range of properties possible with different combinations of nanoparticles and base fluids. In this work, we measure the viscosity of suspensions of graphite particles in ethylene glycol as a function of the volume fraction, shear rate, and temperature below and above the percolation threshold. We also measure and contrast the trends observed in the viscosity with increasing volume fraction to the thermal conductivity behavior of the same suspensions: above the percolation threshold, the slope that describes the rate of thermal conductivity enhancement with concentration reduces compared to below the percolation threshold, whereas that of the viscosity enhancement increases. While the thermal conductivity enhancement is independent of temperature, the viscosity changes show a strong dependence on temperature and exhibit different trends with respect to the temperature at different shear rates above the percolation threshold. Interpretation of the experimental observations is provided within the framework of Stokesian dynamics simulations of the suspension microstructure and suggests that although diffusive contributions are not important for the observed thermal conductivity enhancement, they are important for understanding the variations in the viscosity with changes of temperature and shear rate above the percolation threshold. The experimental results can be collapsed to a single master curve through calculation of a single dimensionless parameter (a Péclet number based on the rotary diffusivity of the graphite particles).United States. Air Force Office of Scientific Research (FA9550-11-1-0174)National Natural Science Foundation (China) (51036003

ROCK2 inhibition enhances the thermogenic program in white and brown fat tissue in mice

The RhoA/ROCK-mediated actin cytoskeleton dynamics have been implicated in adipogenesis. The two ROCK isoforms, ROCK1 and ROCK2, are highly homologous. The contribution of ROCK2 to adipogenesis in vivo has not been elucidated. The present study aimed at the in vivo and in vitro roles of ROCK2 in the regulation of adipogenesis and the development of obesity. We performed molecular, histological and metabolic analyses in ROCK2+/− and ROCK2+/KD mouse models, the latter harboring an allele with a kinase-dead (KD) mutation. Both ROCK2+/− and ROCK2+/KD mouse models showed a lean body mass phenotype during aging, associated with increased amounts of beige cells in subcutaneous white adipose tissue (sWAT) and increased thermogenic gene expression in all fat depots. ROCK2+/− mice on a high-fat diet showed increased energy expenditure accompanying by reduced obesity, and improved insulin sensitivity. In vitro differentiated ROCK2+/− stromal-vascular (SV) cells revealed increased beige adipogenesis associated with increased thermogenic gene expressions. Treatment with a selective ROCK2 inhibitor, KD025, to inhibit ROCK2 activity in differentiated SV cells reproduced the pro-beige phenotype of ROCK2+/− SV cells. In conclusion, ROCK2 activity-mediated actin cytoskeleton dynamics contribute to the inhibition of beige adipogenesis in WAT, and also promotes age-related and diet-induced fat mass gain and insulin resistance

LC–MS-based serum metabolomics analysis for the screening and monitoring of colorectal cancer

BackgroundColorectal Cancer (CRC) is a prevalent digestive system tumour with significant mortality and recurrence rates. Serum metabolomics, with its high sensitivity and high throughput, has shown potential as a tool to discover biomarkers for clinical screening and monitoring of the CRC patients.MethodsSerum metabolites of 61 sex and age-matched healthy controls and 62 CRC patients (before and after surgical intervention) were analyzed using a ultra-performance liquid chromatography-high resolution mass spectrometer (UPLC-MS). Statistical methods and pathway enrichment analysis were used to identify potential biomarkers and altered metabolic pathways.ResultsOur analysis revealed a clear distinction in the serum metabolic profile between CRC patients and healthy controls (HCs). Pathway analysis indicated a significant association with arginine biosynthesis, pyrimidine metabolism, pantothenate, and CoA biosynthesis. Univariate and multivariate statistical analysis showed that 9 metabolites had significant diagnostic value for CRC, among them, Guanosine with Area Under the Curve (AUC) values of 0.951 for the training group and0.998 for the validation group. Furthermore, analysis of four specific metabolites (N-Phenylacetylasparticacid, Tyrosyl-Gamma-glutamate, Tyr-Ser and Sphingosine) in serum samples of CRC patients before and after surgery indicated a return to healthy levels after an intervention.ConclusionOur results suggest that serum metabolomics may be a valuable tool for the screening and monitoring of CRC patients

Chemical Constituents and Digestion-Promoting Effect of Maojian Green Tea

In this study, the digestion-promoting function of an aqueous extract from Maojian green tea extract (MJ-GTE) was evaluated by small intestinal motility in mice as well as body mass, body mass gain, food intake, food utilization rate, gastric pepsin activity, and gastric pepsin excretion in rats. The chemical composition of MJ-GTE was then systematically analyzed using metabolomics based on ultra-high performance liquid chromatography-quadrupole electrostatic orbitrap mass spectrometry (UPLC-Q-Exactive/MS). The results of animal experiments showed that the intestinal propulsion ratio of ink in the high-dose MJ-GTE group (0.83 g/(kg·d)) was significantly increased compared with the model group (P < 0.05), and gastric pepsin excretion in the medium-dose MJ-GTE group (0.21 g/(kg·d)) was significantly increased compared with the negative control group (deionized water) (P < 0.05), which collectively indicated that MJ-GTE has a digestion-promoting effect. The metabolomics analysis identified 98 compounds, among which, flavones (apigenin and luteolin, 0.14–0.77 mg/g), flavanones (naringenin and eriodictyol, 0.49–1.49 mg/g), flavone-7-O-glycosides (0.57–9.07 mg/g), and flavanone-7-O-glycosides (4.49–38.98 mg/g) were the major components in MJ-GTE. This study will provide a theoretical basis for the promotion and development of Maojian green tea and related products in the future

Inhibition of A/Human/Hubei/3/2005 (H3N2) influenza virus infection by silver nanoparticles in vitro and in vivo

AbstractSilver nanoparticles (AgNPs) have attracted much attention as antimicrobial agents and have demonstrated efficient inhibitory activity against various viruses, including human immunodeficiency virus, hepatitis B virus, and Tacaribe virus. In this study, we investigated if AgNPs could have antiviral and preventive effects in A/Human/Hubei/3/2005 (H3N2) influenza virus infection. Madin-Darby canine kidney cells infected with AgNP-treated H3N2 influenza virus showed better viability (P,0.05 versus influenza virus control) and no obvious cytopathic effects compared with an influenza virus control group and a group treated with the solvent used for preparation of the AgNPs. Hemagglutination assay indicated that AgNPs could significantly inhibit growth of the influenza virus in Madin-Darby canine kidney cells (P,0.01 versus the influenza virus control). AgNPs significantly reduced cell apoptosis induced by H3N2 influenza virus at three different treatment pathways (P,0.05 versus influenza virus control). H3N2 influenza viruses treated with AgNPs were analyzed by transmission electron microscopy and found to interact with each other, resulting in destruction of morphologic viral structures in a time-dependent manner in a time range of 30 minutes to 2 hours. In addition, intranasal AgNP administration in mice significantly enhanced survival after infection with the H3N2 influenza virus. Mice treated with AgNPs showed lower lung viral titer levels and minor pathologic lesions in lung tissue, and had a marked survival benefit during secondary intranasal passage in vivo. These results provide evidence that AgNPs have beneficial effects in preventing H3N2 influenza virus infection both in vitro and in vivo, and demonstrate that AgNPs can be used as potential therapeutics for inhibiting outbreaks of influenza.<br /