Fasudil or genetic depletion of ROCK1 or ROCK2 induces anxiety-like behaviors

Twenty-nine protein kinase inhibitors have been used to treat human diseases. Out of these, two are Rho-associated protein kinase (ROCK) 1 and 2 inhibitors. The ROCKs heavily influence neuronal architecture and structural plasticity, and ROCKs are putative drug targets for various brain disorders. While the pan-ROCK inhibitor Fasudil has been clinically approved to treat hypertension, heart failure, glaucoma, spinal cord injury, and stroke, a barrier to progress on this therapeutic avenue is the lack of experimental comparisons between pharmacologic and genetic manipulation of ROCKs. Our study begins to address this question using parallel approaches to study behavior in mice that were treated with Fasudil or were heterozygous for ROCK1 or ROCK2. Adult mice treated with Fasudil for thirty days displayed reduced time spent in the open arms of the elevated plus maze, whereas activity in the open field was more analogous to mock-treated animals. Both male and female adult ROCK1+/- and ROCK2+/- mice exhibited reduced time spent in open arms of the elevated plus maze compared to littermate controls. However, ROCK1 or ROCK2 heterozygosity did not alter performance in the open field or Y-maze. These results indicate that chronic treatment with Fasudil induces anxiety-like behaviors that are likely the consequence of ROCK1 and/or ROCK2 inhibition. Our findings may have implications for several ongoing clinical trials using Fasudil or other ROCK-based therapeutics.

Rho kinase proteins regulate global miRNA expression in endothelial cells

BACKGROUND

Therapeutic targeting of Rho-Associated, Coiled-Coil Containing Protein Kinase (ROCK) signaling for tumor cells and tumor endothelium has shown efficacy in pre-clinical tumors models, and a better understanding of how proteins regulate tumor progression will strengthen our knowledge over disease etiology and treatment of patients with cancer. Recent reports have shown that ROCK activity is critical for the expression of a large number of mRNA transcripts across multiple cell types including endothelial cells.

MATERIALS AND METHODS

To examine the effects of ROCK proteins on microRNA (miRNA) expression in tumor-forming endothelial cells, we utilized microarrays to evaluate expression levels of 1088 miRNAs in vascular tumor-forming endothelial cells knocked-down for ROCK1 or ROCK2 or treated with a pharmacological inhibitor of ROCK activity.

RESULTS

Microarray analysis demonstrated that inhibiting ROCK activity altered global miRNA expression. We confirmed our findings using qPCR and identified cell-cycle progression, calcium transport, and neurogenesis/synaptogenesis as the most highly overrepresented predicted target gene networks for the identified miRNAs whose expression was altered by ROCK inhibition.

CONCLUSION

ROCK signaling induces large-scale changes in global miRNA expression and may lead to a better understanding of how these proteins affect aberrant vascular states.

RhoE participates in the stimulation of the inflammatory response induced by ethanol in astrocytes

Astroglial cells are involved in the neuropathogenesis of several inflammatory diseases of the brain, where the activation of inflammatory mediators and cytokines plays an important role. We have previously demonstrated that ethanol up-regulates inflammatory mediators in both brain and astroglial cells. Since Rho GTPases are involved in inflammatory responses of astrocytes where loss of stress fibers takes place and RhoE/Rnd3 disorganizes the actin cytoskeleton, the aim of the present study was to investigate the implication of this protein in the stimulation of inflammatory signaling induced by ethanol. Our findings show that RhoE expression induces a decrease in both RhoA and Rac. In addition, RhoE not only induces actin cytoskeleton disorganization but it also stimulates both the IRAK/ERK/NF-kappaB pathway and the COX-2 expression associated with the inflammatory response in these cells. Our results also show that ethanol exposure induces RhoE signaling in astrocytes. Preincubation of astrocytes with GF109203X, an inhibitor of PKCs, reduces the RhoE levels and abolishes the ethanol-induced activation of IRAK, NF-kappaB and the COX-2 expression. Furthermore, RhoE overexpression restores ethanol responses in astrocytes treated with the PKCs inhibitor. Altogether, our findings suggest that this small GTPase is involved in the stimulation of the inflammatory signaling induced by ethanol in astrocytes. These findings provide new insights into the molecular mechanism involved in the inflammatory responses in astrocytes.