Inhibitory Effect Of Simvastatin Research Articles

Simvastatin inhibits proliferation and promotes apoptosis of oral squamous cell carcinoma through KLF2 signal

ObjectivesThis study aimed to explore the role and specific mechanism of the cholesterol-lowering drug simvastatin in inhibiting oral squamous cell carcinoma (OSCC). MethodsThe proliferation, apoptosis, and migration levels of OSCC cells were detected by CCK8, quantitative real-time polymerase chain reaction, Western blot, colony formation, TdT-mediated dUTP Nick-End Labeling assay, and wound healing assay. The inhibitory effect of simvastatin in vivo was detected by a mouse xenograft tumor model. Immunohistochemistry and immunofluorescence staining were used to assess the KLF2 and β-catenin expressions in cells and tissues. ResultsKLF2 expression in OSCC cells and tissues was downregulated. The addition of KLF2 inducer, GGTI298, inhibited the proliferation and migration of OSCC cells. Simvastatin played a role in inhibiting the proliferation and promoting the apoptosis of OSCC cells. Moreover, it inhibited β-catenin expression and promoted KLF2 expression in OSCC cells. KLF2 siRNA reversed the effect of simvastatin on the proliferation and apoptosis of OSCC cells. ConclusionsKLF2, as a tumor suppressor gene, may be an important marker for diagnosing and treating OSCC. Simvastatin inhibits the progression of OSCC by regulating the KLF2 signal.

Inhibitory Effects of Simvastatin on IL-33-Induced MCP-1 via the Suppression of the JNK Pathway in Human Vascular Endothelial Cells.

An alarmin, interleukin (IL)-33 is a danger signal that causes inflammation, inducing chemotactic proteins such as monocyte chemoattractant protein (MCP)-1 in various cells. As statins have pleiotropic actions including anti-inflammatory properties, we investigated the effects of simvastatin on IL-33-induced MCP-1 expression in human umbilical vein endothelial cells (HUVECs). HUVECs were stimulated with IL-33 in the presence or absence of simvastatin. Gene expression and protein secretion of MCP-1, phosphorylation of mitogen-activated protein kinase (MAPK), nuclear translocation of phosphorylated c-Jun, and human monocyte migration were investigated. Immunocytochemical staining and Western immunoblot analysis revealed that IL-33 augmented MCP-1 protein expression in HUVECs. Real-time reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) showed that IL-33 significantly increased MCP-1 mRNA and protein secretion, which were suppressed by c-jun N-terminal kinase (JNK) inhibitor SP600125 and p38 MAPK inhibitor SB203580. Simvastatin inhibited IL-33-induced MCP-1 mRNA, protein secretion, phosphorylation of JNK and c-Jun. Additionally, the IL-33-induced nuclear translocation of phosphorylated c-Jun and THP-1 monocyte migration were also blocked by simvastatin. This study demonstrated that IL-33 induces MCP-1 expression via the JNK and p38 MAPK pathways in HUVECs, and that simvastatin inhibits MCP-1 production by selectively suppressing JNK. Simvastatin may inhibit the progression of IL-33-induced inflammation via suppressing JNK to prevent MCP-1 production.

Simvastatin Inhibits Endometrial Cancer Malignant Behaviors by Suppressing RAS/Mitogen-Activated Protein Kinase (MAPK) Pathway-Mediated Reactive Oxygen Species (ROS) and Ferroptosis.

This paper was designed to explore the function of simvastatin as a chemotherapeutic drug on the endometrial cancer (EC) cell proliferation, invasion, and ferroptosis. Firstly, a number of in vitro experiments were conducted to determine the impact of different treatments of simvastatin on the Ishikawa cell invasion, proliferation, and colony formation. The concentration of DCFH-DA-labeled reactive oxygen species (ROS) in cells was assessed by flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was performed to examine the intracellular contents of Fe2+, malondialdehyde (MDA), and glutathione (GSH). Additionally, Western blot was utilized to measure the expression level of RAS/mitogen-activated protein kinase (MAPK)-related proteins and ferroptosis-related proteins in cells. The results showed that simvastatin at 10 μM and 15 μM apparently suppressed the proliferation of Ishikawa cells, colony formation, and invasion ability of Ishikawa cells, and upregulated the level of MDA and ROS, but downregulated the level of GSH. Besides, 10 μM and 15 μM of simvastatin promoted cell ferroptosis (up-regulation of Fe2+ and TRF 1 protein level; down-regulation of SLC7A11 and FPN protein level) and lowered the RAS, p-MEK, and ERK protein level. Furthermore, experiments also revealed that the inhibitory effects of simvastatin on Ishikawa cell proliferation, colony formation, and invasion, as well as the promoting effects on oxidation and ferroptosis were reversed. All in all, simvastatin reduces the RAS/MAPK signaling pathway to inhibit Ishikawa cell proliferation, colony formation, and invasion, and promote cell oxidation and ferroptosis. This paper demonstrates the potential of simvastatin as a new anticancer drug for EC.

Simvastatin and ROCK Inhibitor Y-27632 Inhibit Myofibroblast Differentiation of Graves' Ophthalmopathy-Derived Orbital Fibroblasts via RhoA-Mediated ERK and p38 Signaling Pathways.

Transforming growth factor-β (TGF-β)-induced differentiation of orbital fibroblasts into myofibroblasts is an important pathogenesis of Graves’ ophthalmopathy (GO) and leads to orbital tissue fibrosis. In the present study, we explored the antifibrotic effects of simvastatin and ROCK inhibitor Y-27632 in primary cultured GO orbital fibroblasts and tried to explain the molecular mechanisms behind these effects. Both simvastatin and Y-27632 inhibited TGF-β-induced α-smooth muscle actin (α-SMA) expression, which serves as a marker of fibrosis. The inhibitory effect of simvastatin on TGF-β-induced RhoA, ROCK1, and α-SMA expression could be reversed by geranylgeranyl pyrophosphate, an intermediate in the biosynthesis of cholesterol. This suggested that the mechanism of simvastatin-mediated antifibrotic effects may involve RhoA/ROCK signaling. Furthermore, simvastatin and Y-27632 suppressed TGF-β-induced phosphorylation of ERK and p38. The TGF-β-mediated α-SMA expression was suppressed by pharmacological inhibitors of p38 and ERK. These results suggested that simvastatin inhibits TGF-β-induced myofibroblast differentiation via suppression of the RhoA/ROCK/ERK and p38 MAPK signaling pathways. Thus, our study provides evidence that simvastatin and ROCK inhibitors may be potential therapeutic drugs for the prevention and treatment of orbital fibrosis in GO.

A pharmacokinetic-pharmacodynamic model based on multi-organ-on-a-chip for drug-drug interaction studies.

In drug discovery, the emergence of unexpected toxicity is often a problem resulting from a poor understanding of the pharmacokinetics of drug–drug interactions (DDI). Organ-on-a-chip (OoC) has been proposed as an in vitro model to evaluate drug efficacy and toxicity in pharmacology, but it has not been applied to DDI studies yet. In this study, we aim to evaluate whether organ-on-a-chip technologies can be applied to DDI studies. To assess the usefulness of OoC for DDI studies, we proposed a multi-organ-on-a-chip (MOoC) with a liver part as the metabolic model and a cancer part as the drug target model, and a pharmacokinetic–pharmacodynamic (PK–PD) model describing the MOoC. An anticancer prodrug, CPT-11, was used to evaluate the drug efficacy of the metabolite in the liver part of the MOoC. To evaluate DDI using the MOoC, the inhibitory effect of simvastatin and ritonavir on the metabolism of CPT-11 was tested. The DDI estimation method was evaluated by comparing the results of the concomitant administration experiment using the MOoC and the results of simulation using the proposed PK–PD model with the estimated parameters. The results were similar, suggesting that the combination of the PK–PD model and the MOoC is a useful way to predict DDI. We conclude that OoC technologies could facilitate a better understanding of pharmacokinetic mechanisms with DDI.

Inhibitory effect of simvastatin in nasopharyngeal carcinoma cells.

Nasopharyngeal carcinoma (NPC) is one of the most common malignant head and neck cancers in southern China. Although the local and regional control of NPC has been considerably improved, patients with advanced disease still suffer from poor prognosis. Statins inhibit the mevalonate pathway and play antiproliferative and proapoptotic roles in a number of cancer cells. However, the effects and molecular mechanism of statins in NPC treatment remain unclear. In this study, the cell viability of NPC cell line, C666-1, after simvastatin exposure was determined using the alamarBlue Cell Viability Assay. Cell apoptosis in C666-1 treated with simvastatin was assessed by flow cytometry and TUNEL assay. The expression levels of cell cycle regulatory proteins were determined using western blotting. Simvastatin markedly decreased cell viability in a concentration-dependent manner, increased caspase 3 activity and induced apoptosis in C666-1 cells. Simvastatin induced Bim expression by regulating phosphorylation of transcriptional factor c-Jun. Simvastatin treatment induced cell cycle arrest in the G1 phase in C666-1 cells by inhibiting the expression of cyclin D1 and cyclin-dependent kinase 4, and enhancing p27 expression. Simvastatin treatment inhibited protein kinase B and extracellular signal regulated kinase 1/2 activation. In conclusion, the results of the present study reveal the possible molecular mechanism of simvastatin-induced anti-tumor effects in C666-1 and suggest that simvastatin is a potential chemotherapy agent in NPC treatment.

Statins Reduce Cellular Respiration and Induce De‐differentiation of Myofibroblasts

BackgroundFibroblast to myofibroblast trans‐differentiation with altered bioenergetics precedes cardiac fibrosis (CF). Promotion of de‐differentiation could mitigate CF‐related pathologies; however, no specific remedial therapeutics for CF is clearly defined. Therefore, we determined whether statins, a hypolipidemic class of drugs commonly prescribed in patients at risk of heart failure (HF), can alter cellular bioenergetics and de‐differentiate myofibroblasts.MethodsPrimary cultures of differentiated human ventricular fibroblasts (hVFs) were randomly subjected to in vitro statin treatment (n = 3–6). Differentiation status was determined by α‐smooth muscle actin (α‐SMA) expression while cellular respiration was measured by Seahorse Extracellular Flux Analyzer XF‐96, as oxygen consumption rate (OCR) at baseline and following application of each well with mitochondrial modulators: Oligomycin (1 μg/ml), FCCP (0.1 μM) and antimycin A (1 μg/ml), normalized to total protein. Data were analyzed by either unpaired t test or one‐Way Analysis of Variance.ResultsIn vitro treatment of already differentiated myofibroblasts for 72 hours with both lipophilic (atorvastatin, simvastatin) and hydrophilic (rosuvastatin) statins concentration – dependently reduced α‐SMA/α‐β‐tubulin expression, normalized to % maximal differentiation. The respective IC50 values were 729 ± 13 nM (atorvastatin), 3.6 ± 1 μM (rosuvastatin) and 185 ± 13 nM (simvastatin); n = 3 per concentration of each statin. Basal OCR was significantly decreased in the simvastatin‐treated hVFs vs the differentiated control hVFs (TGF) (0.144 ± 0.026 vs. 0.278 ± 0.104, p = 0.002). Simvastatin reduced the ATP‐linked (0.083 ± 0.018 vs. 0.160 ± 0.059, p = 0.01), the proton leak‐linked (0.017 ± 0.008 vs. 0.074 ± 0.041, p = 0.01) and the maximal (0.250 ± 0.031 vs. 0.501 ± 0.142, p<0.001) OCR, but did not significantly affect spare capacity or non‐mitochondrial OCR. The inhibitory effect of simvastatin on the mitochondrial OCR was reversed by geranylgeranyl pyrophosphate (GGPP, 20 μM ) which significantly increased the basal (0.193 ± 0.053, p = 0.020), the spare‐capacity (0.233 ± 0.091, p = 0.008), and the maximal (0.377 ± 0.131, p = 0.003) OCR, without any change in the non‐mitochondrial OCR. The simvastatin treatment of the differentiated hVFs in vitro reduced ECAR after addition of FCCP (0.066 ± 0.011 vs. 0.093 ± 0.010, p<0.001) and AA (0.056 ± 0.014 vs. 0.097 ± 0.008, p<0.001). GGPP reversed ECAR to a similar level as control differentiated hVFs (FCCP: 0.081 ± 0.015, p = 0.005; AA: 0.080 ± 0.014, p = 0.018). Both atorvastatin (100 nM, 300 nM) and rosuvastatin (300 nM, 1 μM) also increased the ADP/ATP ratio in these cells, confirming the pan‐statin effect of decreased bioenergetics during de‐differentiation. Therefore, statins altered hVF bioenergetics and de‐differentiated the myofibroblasts which involved GGPP‐sensitive mechanisms, reduced cellular respiration with potential activation of KATP channels, as GGPP supplementation or KATP‐channel inhibition by glibenclamide countered the de‐differentiation.ConclusionStatin induced de‐differentiation of myofibroblasts via GGPP‐sensitive signaling, lowered bioenergetics, and KATP channels.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Simvastatin, but not pravastatin, inhibits the proliferation of esophageal adenocarcinoma and squamous cell carcinoma cells: a cell-molecular study

Background and objectiveLong-term statin therapy has been shown to protect against several cancers, including esophageal cancer (EC). While the mechanisms underlying this effect are not clear. We investigated the effect of hydrophobic simvastatin and hydrophilic pravastatin on the proliferation of EC cells and sought to explore the underlying mechanisms.MethodsEsophageal adenocarcinoma OE-19 cells and esophageal squamous cell carcinoma Eca-109 cells were treated with different concentrations of simvastatin or pravastatin for 24 h and 48 h. Cell proliferation was assessed by Cell Counting Kit-8 assay. Malondialdehyde (MDA) levels were measured by thiobarbituric acid (TBA) assay. mRNA and protein expression of COX-2 were determined by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot, respectively; The expression of prostaglandin E2 (PGE2) was measured by ELISA.ResultsSimvastatin, but not pravastatin, significantly inhibited the proliferation of OE-19 and Eca-109 cells in a dose- and time-dependent manner, accompanying with the increasing of the MDA level. Moreover, simvastatin suppressed the expression of COX-2 and PGE2 in both OE-19 and Eca-109 cells in a dose-dependent manner.ConclusionsLipophilic simvastatin, but not hydrophilic pravastatin, had significant inhibitory effects on the proliferation of Eca-109 and OE-19 cells. The reduction of COX-2 and PGE2 by simvastatin suggested that the inhibitory effect of simvastatin on the proliferation of EC cells may be independent of its lipid-lowering effect. Simvastatin may be a promising agent for the prevention and treatment of EC.

Inhibitory Effects of Simvastatin on Oxidized Low-Density Lipoprotein-Induced Endoplasmic Reticulum Stress and Apoptosis in Vascular Endothelial Cells.

Background:Oxidized low-density lipoprotein (ox-LDL)-induced oxidative stress and endothelial apoptosis are essential for atherosclerosis. Our previous study has shown that ox-LDL-induced apoptosis is mediated by the protein kinase RNA-like endoplasmic reticulum kinase (PERK)/eukaryotic translation initiation factor 2α-subunit (eIF2α)/CCAAT/enhancer-binding protein homologous protein (CHOP) endoplasmic reticulum (ER) stress pathway in endothelial cells. Statins are cholesterol-lowering drugs that exert pleiotropic effects including suppression of oxidative stress. This study aimed to explore the roles of simvastatin on ox-LDL-induced ER stress and apoptosis in endothelial cells.Methods:Human umbilical vein endothelial cells (HUVECs) were treated with simvastatin (0.1, 0.5, or 2.5 μmol/L) or DEVD-CHO (selective inhibitor of caspase-3, 100 μmol/L) for 1 h before the addition of ox-LDL (100 μg/ml) and then incubated for 24 h, and untreated cells were used as a control group. Apoptosis, expression of PERK, phosphorylation of eIF2α, CHOP mRNA level, and caspase-3 activity were measured. Comparisons among multiple groups were performed with one-way analysis of variance (ANOVA) followed by post hoc pairwise comparisons using Tukey's tests. A value of P < 0.05 was considered statistically significant.Results:Exposure of HUVECs to ox-LDL resulted in a significant increase in apoptosis (31.9% vs. 4.9%, P < 0.05). Simvastatin (0.1, 0.5, and 2.5 μmol/L) led to a suppression of ox-LDL-induced apoptosis (28.0%, 24.7%, and 13.8%, F = 15.039, all P < 0.05, compared with control group). Ox-LDL significantly increased the expression of PERK (499.5%, P < 0.05) and phosphorylation of eIF2α (451.6%, P < 0.05), if both of which in the control groups were considered as 100%. Simvastatin treatment (0.1, 0.5, and 2.5 μmol/L) blunted ox-LDL-induced expression of PERK (407.8%, 339.1%, and 187.5%, F = 10.121, all P < 0.05, compared with control group) and phosphorylation of eIF2α (407.8%, 339.1%, 187.5%, F = 11.430, all P < 0.05, compared with control group). In contrast, DEVD-CHO treatment had no significant effect on ox-LDL-induced expression of PERK (486.4%) and phosphorylation of eIF2α (418.8%). Exposure of HUVECs to ox-LDL also markedly induced caspase-3 activity together with increased CHOP mRNA level; these effects were inhibited by simvastatin treatment.Conclusions:This study suggested that simvastatin could inhibit ox-LDL-induced ER stress and apoptosis in vascular endothelial cells.

Effects of simvastatin on the proliferation, invasion and radiosensitivity in Lewis lung cancer cell line

Objective: To investigate the effects of simvastatin on proliferation, invasion and radiosensitivity of mouse Lewis lung cancer cell line in vitro. Methods: The inhibitory effects of simvastatin on proliferation of Lewis lung cancer cells were detected by MTT assay. Matrigel invasion and migration assay was used to determine the invasion and motility ability of the Lewis cells. P38 activity was measured by p38 activity detection kit, and the expressions of p-p38, MKP-1, RhoA and MMP-2 were analyzed by Western blot. Lung cancer xenograft model was established in C57BL/6 mice. The mice were randomly divided into control group, simvastatin group, radiotherapy alone group and combined treatment group. The mice were killed 27 days after inoculation. The tumor mass, volume and lung metastatic nodules in the mice were compared. Results: The cell proliferation rates of 0 μmol/L, 10 μmol/L, 20 μmol/L and 30 μmol/L simvastatin groups were 100%, (87.0±9.0)%, (76.5±8.1)% and (67.0±7.3)%, respectively (P<0.05). Invasive cell numbers of the above groups were 298±30, 251±26, 207±20 and 132±19 per field, respectively (P<0.05). The intracellular p38 activities were 100%, (83.1±8.8)%, (70.2±8.2)% and (59.0±6.4)%, respectively. The relative expressions of p-p38 were 100%, (76.2±6.7)%, (56.4±5.4)% and (36.5±3.2)%, respectively. The expressions of RhoA were 100%, (80.1±5.3)%, (55.3±6.2)% and (38.6±4.8)%, respectively. The expressions of MMP-2 were 100%, (89.6±8.6)%, (51.9±4.7)% and (42.7±3.1)%, respectively, while the expressions of MKP-1 were 100%, (136.5±12.2)%, (168.8±15.3)% and (187.7±13.4)%, respectively (all P<0.05). Lung metastatic nodules and mass in the control, simvastatin, radiotherapy group and combined treatment groups were 6.24±1.09, 3.07±0.71 g, 5.09±1.16, 2.43±0.53 g, 3.12±0.68, 1.96±0.62 g and 2.65±0.38, 1.12±0.43 g, respectively (all P<0.05). The tumor inhibition rates were 39.0%, 48.1% and 26.5%, respectively, in the radiotherapy alone, combined treatment and simvastatin groups (all P<0.05). Conclusions: Simvastatin inhibits the proliferation of Lewis cell line by inhibiting the activity of p38 and expression of p-p38. Meanwhile, simvastatin reduces the invasion and motility of Lewis cell line through down-regulating the expression of RhoA and MMP-2. When combined with radiotherapy, simvastatin can inhibit tumor growth and metastasis, and improve the treatment efficacy of radiotherapy synergistically.

Chamber-specific differences in human cardiac fibroblast proliferation and responsiveness toward simvastatin.

Fibroblasts, the most abundant cells in the heart, contribute to cardiac fibrosis, the substrate for the development of arrythmogenesis, and therefore are potential targets for preventing arrhythmic cardiac remodeling. A chamber-specific difference in the responsiveness of fibroblasts from the atria and ventricles toward cytokine and growth factors has been described in animal models, but it is unclear whether similar differences exist in human cardiac fibroblasts (HCFs) and whether drugs affect their proliferation differentially. Using cardiac fibroblasts from humans, differences between atrial and ventricular fibroblasts in serum-induced proliferation, DNA synthesis, cell cycle progression, cyclin gene expression, and their inhibition by simvastatin were determined. The serum-induced proliferation rate of human atrial fibroblasts was more than threefold greater than ventricular fibroblasts with faster DNA synthesis and higher mRNA levels of cyclin genes. Simvastatin predominantly decreased the rate of proliferation of atrial fibroblasts, with inhibition of cell cycle progression and an increase in the G0/G1 phase in atrial fibroblasts with a higher sensitivity toward inhibition compared with ventricular fibroblasts. The DNA synthesis and mRNA levels of cyclin A, D, and E were significantly reduced by simvastatin in atrial but not in ventricular fibroblasts. The inhibitory effect of simvastatin on atrial fibroblasts was abrogated by mevalonic acid (500 μM) that bypasses 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibition. Chamber-specific differences exist in the human heart because atrial fibroblasts have a higher proliferative capacity and are more sensitive to simvastatin-mediated inhibition through HMG-CoA reductase pathway. This mechanism may be useful in selectively preventing excessive atrial fibrosis without inhibiting adaptive ventricular remodeling during cardiac injury.

Carboxylesterase 1-mediated drug-drug interactions between clopidogrel and simvastatin.

Patients with coronary artery disease often receive concurrent treatment with clopidogrel and a hydroxymethylglutaryl (HMG)-CoA reductase inhibitor medication. Accordingly, potential drug-drug interactions associated with the concomitant use of these agents present an area of concern. Both CYP enzymes and carboxylesterase 1 (CES1) are involved in the metabolism of clopidogrel, while CES1 is believed to be the enzyme responsible for the activation of simvastatin. Some in vitro studies have suggested that simvastatin could attenuate clopidogrel activation via inhibiting CYP3A activity. However, these findings have not found support in several recently published clinical investigations. The present study addresses these inconsistencies by exploring the potential role of CES1 in the metabolism of clopidogrel and simvastatin. Our in vitro human liver s9 fraction incubation study demonstrated that simvastatin significantly enhanced the formation of the intermediate metabolite 2-oxo-clopidogrel, and inhibited the CES1-mediated hydrolysis of clopidogrel, 2-oxo-clopidogrel, and the active metabolite. However, the production of the active metabolite remained unchanged. Conversely, clopidogrel was not found to influence the CES1 mediated hydrolysis (activation) of simvastatin. Moreover, we provided evidence that CES1 is not an efficient enzyme for catalyzing simvastatin activation. In summary, the inhibitory effect of simvastatin on the hydrolysis of clopidogrel and its principal metabolites may have offset the influence of simvastatin-mediated inhibition of CYP3A, and permitted the unaltered formation of the clopidogrel active metabolite. These data help explain the conflicting accounts in previous reports regarding clopidogrel and simvastatin interactions by taking into consideration CES1; they suggest that the interactions are unlikely to significantly influence clinical outcomes.

Abstract 329: Simvastatin Inhibits TGF-β1-induced Proliferation and Activation of Cardiac Fibroblasts Through Inhibition of SMAD Pathway

Background: HMG-CoA reductase inhibitors (statins) have been shown to reduce the incidence of atrial fibrillation (AF) and its progression but the underlying mechanisms are not fully elucidated. Since atrial fibrosis plays a major role in the development of the substrate for AF progression, we hypothesized that statins antagonize the effect of profibrotic cytokines, reducing their stimulatory effect on fibroblast proliferation, differentiation and activation. Methods: The effect of TGF-β1, a major profibrotic cytokine, on fibroblast proliferation and activation of myofibroblasts was assessed by expression of alpha smooth muscle actin (α-SMA) message (qPCR) and proteins (western and immunofluorocytochemistry) in the presence and absence of simvastatin (1-10μM). The inhibitory effect of simvastatin on SMAD 2/3 phosphorylation (western) and its nuclear translocation by TGF-β1 (5ng) was determined by immunofluorescence antibodies using fluorescent microscopy. Results: TGF-β1 treatment increased fibroblast proliferation (cell count) by 63% compared to control (p&lt;0.001) at 96 hours, which was inhibited by simvastatin by 61% (p&lt;0.001) (Fig a). Simvastatin also reduced TGF-β1-mediated myofibroblast differentiation (α-SMA positive) by 75% (p=0.02); (Fig b and c). TGF-β1 increased SMAD2/3 phosphorylation with increase in nuclear localization was inhibited by simvastatin. Conclusion: Simvastatin inhibits TGFβ-1-mediated cardiac fibroblast proliferation and myofibroblast differentiation by antagonizing SMAD phosphorylation and its translocation into the nucleus.

The inhibitory effect of simvastatin and aspirin on histamine responsiveness in human vascular endothelial cells

Statins and aspirin deliver well-established cardiovascular benefits resulting in their increased use as combined polypills to decrease risk of stroke and heart disease. However, the direct endothelial effect of combined statin/aspirin cotreatment remains unclear. Histamine is an inflammatory mediator that increases vascular permeability, and so we examined the effect of treating human umbilical vein endothelial cells (HUVECs) for 24 h with 1 μM simvastatin and 100 μM aspirin on histamine responsiveness. Subsequent histamine (1 μM) challenge increased intracellular calcium (Ca(2+)i) concentration, an effect that was significantly inhibited by combined simvastatin/aspirin pretreatment but not when then the compounds were given separately, even at 10-fold higher concentrations. In contrast, the Ca(2+)i mobilization response to ATP challenge (10 μM) was not inhibited by combined simvastatin/aspirin pretreatment. The H1 receptor antagonist pyrilamine significantly inhibited both histamine-induced Ca(2+)i mobilization and extracellular signal-regulated kinase (ERK) activation, whereas ranitidine (H2 receptor antagonist) was without effect. However, combined simvastatin/aspirin pretreatment failed to decrease H1 receptor protein expression ruling out receptor downregulation as the mechanism of action. Histamine-induced ERK activation was also inhibited by atorvastatin pretreatment, while simvastatin further inhibited histamine-induced vascular endothelial cadherin phosphorylation as well as altered HUVEC morphology and inhibited actin polymerization. Therefore, in addition to the known therapeutic benefits of statins and aspirin, here we provide initial cellular evidence that combined statin/aspirin treatment inhibits histamine responsiveness in HUVECs.

Simvastatin Inhibits Renal Cancer Cell Growth and Metastasis via AKT/mTOR, ERK and JAK2/STAT3 Pathway

Renal cell carcinoma (RCC) is the most lethal type of genitourinary cancer due to its occult onset and resistance to chemotherapy and radiation. Recently, accumulating evidence has suggested stains, inhibitors of 3-hydroxy-3-methyl glutaryl coenzyme A (HMG-CoA) reductase, were associated with the risk reduction of cancer. In the present study, we aimed to investigate the potential effects of simvastatin on RCC cells and the underlying mechanisms by which simvastatin exerted its actions. With cell viability, colony formation, and flow cytometric apoptosis assays, we found that simvastatin potently suppressed cell growth of A498 and 786-O cells in a time- and dose- dependent manner. Consistently, the xenograft model performed in nude mice exhibited reduced tumor growth with simvastatin treatment. In addition, the inhibitory effects of simvastatin on migration and invasion were also observed in vitro. Mechanically, we presented that simvastatin could suppress the proliferation and motility of RCC cells via inhibiting the phosphorylation of AKT, mTOR, and ERK in a time- and dose- dependent manner. Further investigation of the underlying mechanism revealed simvastatin could exert the anti-tumor effects by suppressing IL-6-induced phosphorylation of JAK2 and STAT3. In conclusion, these findings suggested that simvastatin-induced apoptosis and its anti-metastasis activity in RCC cells were accompanied by inhibition of AKT/mTOR, ERK, and JAK2/STAT3 pathways, which imply that simvastatin may be a potential therapeutic agent for the treatment of RCC patients.

Inhibitory effects of simvastatin on staphylococcus aureus lipoteichoic acid-induced inflammation in human alveolar macrophages

Staphylococcus aureus (S. aureus) is the most common bacterium in sepsis and pneumonia involving gram-positive bacteria. Lipoteichoic acid (LTA) is a cell wall component of gram-positive bacteria. It is a potent inducer of inflammatory mediators in human dendritic cells, human pulmonary epithelial cells, and murine macrophages. However, the effect of LTA on human alveolar macrophages (AMs) which are the major effector cells in host defense against respiratory tract infections has hardly been studied. Statins have anti-inflammatory, immunomodulatory, antioxidative, anticoagulant, and antibacterial activities. These effects may be contributed to reduce the markers of systemic inflammation. Emerging retrospective studies have demonstrated that statin use decreased the mortality of pneumonia. However, the precise mechanisms responsible for these effects are unclear. The purpose of this study is to define the role of S. aureus LTA in human AMs and the effects of simvastatin (SV) on LTA-stimulated human AMs. The results showed that LTA induced tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), IL-8 mRNA expression, and suppressed IL-10 mRNA expression in human AMs. Simultaneously, LTA induced human AMs apoptosis. These effects were parallel with the up-regulation of the expression of NF-κB-P65 protein in the LTA-stimulated human AMs. The above effects of LTA on human AMs were inhibited significantly by SV. These data indicate that S. aureus LTA induces potent pro-inflammatory and pro-apoptotic effects on human AMs and statins exert anti-inflammatory effects by mediating inhibition of NF-κB activation and cytokine mRNA expression in human AMs. These results may explain, in part, the mechanisms responsible for favorable effects of statins on pneumonia.

Involvement of geranylgeranylation of Rho and Rac GTPases in adipogenic and RANKL expression, which was inhibited by simvastatin

Simvastatin suppresses myoblast differentiation via inhibition of Rac GTPase, which is involved in the mevalonic acid pathway that produces cholesterol. Statins also inhibit adipogenic differentiation and receptor activator of NFκB ligand (RANKL) expression, possibly through the mevalonic acid pathway, although the involvement of that pathway and effector proteins in these cellular events has not been fully clarified. In the present study, we aimed to elucidate the mechanism of the effects of simvastatin on adipogenic differentiation and calcitriol-induced RANKL expression in bone marrow stromal ST2 cells. Adipogenesis and mRNA up-regulation of peroxisome proliferator-activated receptor γ and adipocyte fatty acid-binding protein were induced by troglitazone, and those events were efficiently inhibited by simvastatin. In addition, RANKL expression induced by calcitriol was abrogated by simvastatin in ST2 cells. The inhibitory effects of simvastatin were adequately compensated by the addition of either mevalonic acid or an intermediate of the mevalonic acid pathway, geranylgeranyl pyrophosphate, but not by another intermediate, farnesyl pyrophosphate. These findings suggest that protein geranylgeranylation is related to cellular differentiation in those two directions. Furthermore, inhibitor analysis demonstrated that Rac GTPase is involved in adipogenic differentiation, whereas Rho GTPase was found to be involved in RANKL expression. Taken together, the present findings suggest that geranylgeranylation of Rho family GTPase is involved in both adipogenesis and RANKL expression of stromal cells, while Rac GTPase is involved in adipogenesis and Rho GTPase in RANKL expression.

Enhancement of Autophagy by Simvastatin through Inhibition of Rac1-mTOR Signaling Pathway in Coronary Arterial Myocytes

Background/Aims: In addition to their action of lowering blood cholesterol levels, statins modulate biological characteristics and functions of arterial myocytes such as viability, proliferation, apoptosis, survival and contraction. The present study tested whether simvastatin, as a prototype statin, enhances autophagy in coronary arterial myocytes (CAMs) to thereby exert their beneficial effects in atherosclerosis. Methods and Results: Using flow cytometry, we demonstrated that simvastatin significantly increased the autophagsome formation in CAMs. Western blot analysis confirmed that simvastatin significantly increased protein expression of typical autophagy markers LC3B and Beclin1 in these CAMs. Confocal microscopy further demonstrated that simvastatin increased fusion of autophagosomes with lysosomes, which was blocked by autophagy inhibitor 3-methyladenine or silencing of Atg7 genes. Simvastatin reduced mammalian target of rapamycin (mTOR) activity, which was reversed by Rac1-GTPase overexpression and the mTOR agonist phosphatidic acid. Moreover, both Rac1-GTPase overexpression and activation of mTOR by phosphatidic acid drastically blocked simvastatin-induced autophagosome formation in CAMs. Interestingly, simvastatin increased protein expression of a contractile phenotype marker calponin in CAMs, which was blocked by autophagy inhibitor 3-methyladenine. Simvastatin markedly reduced proliferation of CAMs under both control and proatherogenic stimulation. However, this inhibitory effect of simvastatin on CAM proliferation was blocked by by autophagy inhibitor 3-methyladenine or silencing of Atg7 genes. Lastly, animal experiments demonstrated that simvastatin increased protein expression of LC3B and calponin in mouse coronary arteries. Conclusion: Our results indicate that simvastatin inhibits the Rac1-mTOR pathway and thereby increases autophagy in CAMs which may stabilize CAMs in the contractile phenotype to prevent proliferation and growth of these cells.

The Effects of Simvastatin or Interferon-α on Infectivity of Human Norovirus Using a Gnotobiotic Pig Model for the Study of Antivirals

The lack of an animal model for human norovirus (HuNoV) has hindered the development of therapeutic strategies. This study demonstrated that a commonly used cholesterol-lowering statin medication, simvastatin, which increases HuNoV replication in an in vitro replicon system, also enhances HuNoV infectivity in the gnotobiotic (Gn) pig model. In contrast, oral treatment with interferon (IFN)-α reduces HuNoV infectivity. Young piglets, all with A or H1 histo-blood group antigens on enterocytes, were treated orally with 8 mg/kg/day of simvastatin; 5 days later, the pigs were inoculated orally with a GII.4 HuNoV (HS194/2009/US strain) and then treated with simvastatin for 5 more days. Simvastatin induced significantly earlier onset and longer duration of HuNoV fecal shedding in treated pigs, frequently with higher fecal viral titers. Simvastatin impaired poly (I:C)-induced IFN-α expression in macrophages or dendritic cells, possibly due to lowered toll-like receptor (TLR) 3 expression; however, the mechanisms were not related to interferon regulatory factor 3 or nuclear factor kappa B signaling pathway. Thus, the enhanced, earlier infectivity of HuNoV in simvastatin-treated pigs coincided with the inhibitory effect of simvastatin on innate immunity. In contrast to the increased HuNoV shedding that simvastatin induced, viral shedding during the treatment period was reduced or curtailed in the HuNoV-inoculated pigs pre-treated/treated with human IFN-α. Our findings are the first to indicate that IFN-α has potential as antiviral therapy against HuNoV. Based on these intriguing and novel findings using the Gn pig model, we confirmed that HuNoV infectivity is altered by treatment with simvastatin or IFN-α. Collectively, these findings indicate that Gn pigs are a useful model to test immunomodulators or efficacy of antivirals against HuNoV.

Mo2009 Inhibitory Effect of Simvastatin on Colonic Fibrosis in Rats With Crohn's Disease

Introduction: Recent evidences suggest therapeutic value of mesenchymal stem cells (MSCs) as anti-inflammatory and immunomodulatory agent against several autoimmune diseases. Although promising, stem cell based therapies for IBD still requires experimental validation. In the present study we sought to determine whether exogenous administration of human umbilical cord derived cells with phenotype consistent with MSCs (UC-MSCs) can reduce acute colonic damage induced by Dextran Sulphate Sodium (DSS) in immunodeficient NOD.CB17-Prkdcscid/Jmice.Methods: UC-MSCs isolatedwere evaluated by assessing CD73, CD90, CD166, CD105, CD29, CD44, HLA-DR and c-kit expression, by adipocyte, osteocyte differentiation and proliferation potential by cell cycle analysis and wound assay. UC-MSCs were injected in NOD.CB17-Prkdcscid/J mice via tail vein at day 1 and 4. Disease Activity Index, daily body weight changes and colon length, and histological changes evaluated on day 7. Myeloperoxidase, catalase activities, chromosome aberration, sperm head anomaly and metalloproteinase (MMP) 2, 9 expressions were assessed in mice to verify attenuation of DSS induced damage by UC-MSCs. Alteration of ER stress related proteins like BIP, PERK, PDI, CHOP were studied by western blotting. Results: UC-MSC differentiated in osteocytes/ adipocytes, highly expressed CD90, CD73, CD166, CD105 andCD29 typical ofmesenchymal stem cells. UC-MSCs were successfully engrafted in the colon as evident from immunohistochemical staining against anti human nuclei antibody. UC-MSCs administration significantly attenuated bloody stool, weight loss, colon shortening and accelerated healing of damaged mucosa. Decrease in cytotoxicity and genotoxicity was evident from lower MPO level (78.2±9.7 vs 168.9±18.2 U/g, p 3 fold) which were reduced in UC-MSC group. Positive modulation in BIP, PERK, PDI proteins was noticed after MSC administration. Conclusions: NOD.CB17-Prkdcscid/J mice were susceptible to acute DSS colitis, suggesting that T, B and NK cells are not required for the disease. The engrafted UC-MSCs successfully accelerated healing of DSS-induced damaged tissue by promoting tissue repair process by reducing the protease burden through reduced MMP expression in inflammed colon and positively modulating histological score supporting the use of MSCs as a novel therapeutic strategy for colonic injuries. Future works in this direction would hopefully resolve the minutes of this inspiring cell therapy in alleviation of human sufferings involving IBDs.