Effect of Rho kinase inhibitor fasudil on the expression ET-1 and NO in rats with hypoxic pulmonary hypertension.

OBJECTIVE: This study aims to study the effect of Rho kinase inhibitor fasudil on the expression endothelin-1 (ET-1) and nitric oxide (NO) in rats with hypoxic pulmonary hypertension (HPH). METHODS: Twenty-four male SD rats were randomly divided into three groups: control group, model group (HPH group) and HPH+fasudil group. The rat HPH model was established by intermittent hypoxia (IH) at atmospheric pressure. Mean pulmonary artery pressure (mPAP), right ventricular hypertrophy index (RVHI), ET-1 and NO levels, and pulmonary vascular structural changes were observed in all groups. RESULTS: MPAP, RVHI and ET-1 levels were significantly higher in HPH group than in control group, while NO was significantly lower than in control group. In addition, mPAP, RVHI and ET-1 were significantly lower in the HPH+fasudil group than in the HPH group. In the HPH group, ET-1 level was significantly and positively correlated with mPAP and RVHI, NO was negatively correlated with mPAP and RVHI levels, and ET-1 level was significantly and negatively correlated with NO level. In the HPH group, pulmonary arteriolar walls were generally thickened, and lumen stenosis was obvious; while after fasudil treatment, pulmonary arteriolar wall thickening and stenosis degree were significantly reduced. CONCLUSION: Fasudil can significantly reduce ET-l level and increase NO level in HPH rats, suppressing the development of pulmonary arterial hypertension.

Actein induces apoptosis in leukemia cells through suppressing RhoA/ROCK1 signaling pathway.

Actein is a tetracyclic triterpenoid compound, extracted from the rhizome of Cimicifuga foetida, exhibiting anticancer activities as previously reported. However, the effects of actein on human leukemia have not been explored before. In this study, the role of actein in regulating apoptosis induction in human leukemia cells was investigated. Actein administration significantly enhanced apoptosis, especially in human leukemia cell line of U937 and the primary human leukemia cells. The promotion was accompanied by caspase-9, caspase-3 and poly(ADP-ribose) polymerase (PARP) cleavage, and cytochrome c (Cyto-c) release. Additionally, translocation of Bax into mitochondria was increased by actein, while anti-apoptotic signals of myeloid cell leukemia-1 (Mcl-1) and B cell CLL/lymphoma 2 (Bcl-2) were decreased, accompanied by reduced phosphorylated Bcl-2-associated death promoter (Bad). Furthermore, protein kinase B (AKT) activation was downregulated by actein treatment in U937 cells. RhoA, but not caspase-3, regulated Rho kinase 1 (ROCK1) expression induced by actein. Suppression of RhoA and ROCK1 reduced ROCK1 expression, caspase-9, caspase-3 and PARP cleavage. In contrast, AKT inactivity enhanced apoptosis levels, as well as caspase signaling pathway expression. The anticancer role of actein was potentiated by inactivating AKT. In vivo, U937-bearing tumor growth was suppressed by actein, which was related to ROCK1 suppression, AKT dephosphorylation and apoptosis induction. These results indicated that actein has a suppressive role in human leukemia progression through inactivating RhoA/ROCK1 and inducing caspases.

Bakkenolide A inhibits leukemia by regulation of HDAC3 and PI3K/Akt-related signaling pathways.

Leukemia has been the third type of cancer killing many people across the world. Bakkenolide A (Bak), extracted from Petasites tricholobus, has been suggested to against cancer and display protective effects on inflammatory cytokines formation. And increasing evidences suggest that histone deacetylase 3 (HDAC3) plays vital roles in cancer formation and persistence via cell death, apoptosis and inflammation. But the function of Bakkenolide A in regulating leukemia is not understood yet, particularly via HDAC3. Here, we found that HDAC3 is up-regulated in clinical samples of leukemia compared with adjacent normal tissues. Then the expression of HDAC3 was knocked down via RNA interference in K562 cells. And inhibition of HDAC3 expression is able to improve leukemia invasion, migration and proliferation. Further, we also found HDAC3 bound to IκBα, affecting subsequent inflammation response. Moreover, Bakkenolide A was found to inhibit inflammation, induce apoptosis and cell death in leukemia cells via PI3K-regulated signaling pathway, down-regulating IKKs expression and suppressing in proinflammatory cytokines of IL-1ß, IL-18 and TNF-α. Up-regulation of Caspase3/7 was observed in cells of HDAC3-knockdown and Bakkenolide A treatment, inducing leukemia cell apoptosis. Also, the expression of Akt and GSK were activated by HDAC3-knockdown and Bakkenolide A-treatment. Thus, these results indicated that Bakkenolide A-mediated HDAC3 sensitization in leukemia cells seem to be associated with activation of effector IKKs, Akt/GSK, and caspases through induction of the PI3K pathway, leading to inflammation, cell death, and apoptosis.

Effect of fasudil on hypoxic pulmonary hypertension and right ventricular hypertrophy in rats.

OBJECTIVE: To investigate whether right ventricular hypertrophy in hypoxic pulmonary hypertension (HPH) rats could be prevented by treatment with Rho kinase inhibitor fasudil. METHODS: The rat model of pulmonary hypertension was established by exposing rats to normobaric intermitent hypoxia [(10 ± 0.5)% O2]. Twenty-four Spraque-Dawley male rats were randomly divided into control group, hypoxic model group and hypoxia with fasudil groups (n=8 each). The mean pulmonary arterial pressure (mPAP), and right ventricle hypertrophy index (RVHI) were measured. Ultrastructure of the right ventricular myocardial cells was observed under transmission electron microscope (TEM). - RESULTS: The level of mPAP (31.38 ± 1.98) mmHg and RVHI (0.47 ± 0.03) were significantly higher in the hypoxic model group than (15.25 ± 0.91) mmHg and (0.25 ± 0.02) in control group respectively (P<0.01). Transmission electron microscope (TEM) revealed the model group right ventricular mitochondria increased significantly, swelling, cristae blurred, lost, heart muscle Siming dark band was not clear. The level of mPAP (16.63 ± 1.53) mmHg and RVHI (0.27 ± 0.02) were significantly lower in fasudil treatment group than in model group respectively (P<0.01). After the intervention of fasudil right ventricular myocardial injury was significantly reduced. CONCLUSIONS: Fasudil may partly prevent and reverse the development of pulmonary hypertension and right ventricular hypertrophy and myocardial cell injury.