Tetramethylpyrazine induces G0/G1 cell cycle arrest and stimulates mitochondrial-mediated and caspase-dependent apoptosis through modulating ERK/p53 signaling in hepatic stellate cells in vitro. Apoptosis. 2013;18:135-149. [PMID: 23247439 DOI: 10.1007/s10495-012-0791-5]

Structural characterization of an inulin neoseries-type fructan from Ophiopogonis Radix and the therapeutic effect on liver fibrosis in vivo

Ophiopogonis Radix is a well-known Traditional Chinese Medicine and functional food that is rich in polysaccharides and has fructan as a characteristic component. In this study, an inulin neoseries-type fructan designated as OJP-W2 was obtained and characterized from Ophiopogonis Radix, and its potential therapeutic effect on liver fibrosis in vivo were investigated. Structural studies revealed that OJP-W2 had a molecular weight of 5.76 kDa and was composed of glucose and fructose with a molar ratio of 1.00:30.87. Further analysis revealed OJP-W2 has a predominantly lineal (1-2)-linked β-D-fructosyl units linked to the glucose moiety of the sucrose molecule with (2-6)-linked β-D-fructosyl side chains. Pharmacological studies revealed that OJP-W2 exerted a marked hepatoprotective effect against liver fibrosis, the mechanism of action was involved in regulating collagen deposition (α-SMA, COL1A1 and liver Hyp contents) and TGF-β/Smads signaling pathway, alleviating liver inflammation (IL-1β, IL-6, CCL5 and F4/80) and MAPK signaling pathway, and inhibiting hepatic apoptosis (Bax, Bcl-2, ATF4 and Caspase 3). These data provide evidence for expanding Ophiopogonis Radix-acquired fructan types and advancing our understanding of the specific role of inulin neoseries-type fructan in liver fibrosis therapy.

Improved Tumor Infiltration and Immunomodulation for Tumor Therapy: A Pathway Based on Tetrahedral Framework Nucleic Acids Coupled Bacterial Nanocells

Growing evidence indicates that the tumor microenvironment (TME) can be combined with other therapeutic modalities, including cytotoxic chemotherapy and targeted therapies, to produce unanticipated results in oncology treatment. Here, we proposed a novel bacterial nanomaterial capable of targeting peritumoral biofilm and modulating TME. It was based on tetrahedral framework nucleic acids (T) that were chemically attached to aptamer AS1411 and 5-fluorouracil (AT5). Additionally, the oral pathogenic bacterium Streptococcus mutans (S.m) was employed as a biocarrier for synergetic biofilm targeting and immunomodulation. In this article, the effect of AT5-coupled S.m-derived nanocells (S.m-AT5) was investigated in vitro and in vivo. Due to bacteria aggregation in the tumor-specific biofilm, these nanocells released greater medication concentrations. Furthermore, they exerted an immunomodulatory effect by stimulating the maturation of dendritic cells (DCs) and regulation of T cells. This chemo-immunostimulation combination has a powerful antitumor impact. It may also be an advanced approach for boosting the survival rate of cancer patients.

Diazinon toxicity in hepatic and spleen mononuclear cells is associated to early induction of oxidative stress

Diazinon is an organophosphorus pesticide, which may have potential toxic effects on the liver and immune system; however, the underlying mechanisms remain mostly unidentified. This work is aimed at evaluating the oxidative stress and cell cycle alterations elicited by low-dose diazinon in a rat liver cell line (BRL-3A) and spleen mononuclear cells (SMC) from Wistar rats. Diazinon (10-50 μM) caused early reactive oxygen species (ROS) generation (from 4 h) as well as increased O₂^•- level (from 0.5 h), which led to subsequent lipid peroxidation at 24 h, in BRL-3A cells. In SMC, diazinon (20 μM) produced similar increases in ROS levels, at 4 and 24 h, with the highest O₂^•- level being found at 4 h. Low-dose diazinon induced G1-phase arrest and cell death in hepatic cells and SMC. Therefore, diazinon could affect the liver and the immunological system through the premature oxidative stress induction.Abbreviations: O₂^•-: superoxide anion radical; ROS: reactive oxygen species; SMC: spleen mononuclear cells; TBARS: thiobarbituric acid reactive substances.

Tetramethylpyrazine: A review on its mechanisms and functions

Ligusticum chuanxiong Hort (known as Chuanxiong in China, CX) is one of the most widely used and long-standing medicinal herbs in China. Tetramethylpyrazine (TMP) is an alkaloid and one of the active components of CX. Over the past few decades, TMP has been proven to possess several pharmacological properties. It has been used to treat a variety of diseases with excellent therapeutic effects. Here, the pharmacological characteristics and molecular mechanism of TMP in recent years are reviewed, with an emphasis on the signal-regulation mechanism of TMP. This review shows that TMP has many physiological functions, including anti-oxidant, anti-inflammatory, and anti-apoptosis properties; autophagy regulation; vasodilation; angiogenesis regulation; mitochondrial damage suppression; endothelial protection; reduction of proliferation and migration of vascular smooth muscle cells; and neuroprotection. At present, TMP is used in treating cardiovascular, nervous, and digestive system conditions, cancer, and other conditions and has achieved good curative effects. The therapeutic mechanism of TMP involves multiple targets, multiple pathways, and bidirectional regulation. TMP is, thus, a promising drug with great research potential.

The mechanism research on the anti-liver fibrosis of emodin based on network pharmacology

AIMS

This study was designated to illustrate the underlying mechanisms of emodin anti-liver fibrosis via network pharmacology and experiment.

METHODS

The TSMCP and Genecards database were applied to screen the relevant targets of emodin or liver fibrosis. The essential target was selected by using Cytoscape to analyze the topological network of potential targets. Furthermore, we constructed a preliminary molecule docking study to explore the binding site by Surflex-Dock suite SYBYL X 2.0. The DAVID database was selected for gene functional annotations and KEGG enrichment analysis. Moreover, we demonstrated the ameliorating effect of emodin on carbon tetrachloride (CCl4 )-induced liver injury in mice. We also verified the network predictions in vitro via various techniques.

RESULTS

The collected results showed that 35 targets were related to emodin, and 6,198 targets were associated with liver fibrosis. The Venn analysis revealed that 17 intersection targets were correlated with emodin anti-liver fibrosis. The topological network analysis suggested that the p53 was the remarkable crucial target. Besides, the molecule docking results showed that emodin could directly interact with p53 by binding the active site residues ASN345, GLN331, and TYR347. Finally, KEGG pathway enrichment results indicated that essential genes were mainly enriched in mitogen-activated protein kinase (MAPK) signaling pathways. Moreover, our study confirmed that emodin alleviated CCl4 -induced liver injury in mice, inducing hepatic stellate cells (HSCs) apoptosis via regulating the p53/ERK/p38 axis.

CONCLUSIONS

This study partially verified the network pharmacological prediction of emodin inducing HSCs cell apoptosis through the p53/ERK/p38 axis.

Biofabrication of ecofriendly copper oxide nanoparticles using Ocimum americanum aqueous leaf extract: analysis of in vitro antibacterial, anticancer, and photocatalytic activities

Nanotechnology tends to be a swiftly growing field of research that actively influences and inhibits the growth of bacteria/cancer. Noble metal nanoparticles (NPs) such as silver, copper, and gold have been used to damage bacterial and cancer growth over recent years; however, the toxicity of higher NPs concentrations remains a major issue. The copper oxide nanoparticles (CuONPs) were therefore fabricated using a simple green chemistry approach. Biofabricated CuONPs were characterized using UV-visible, FE-SEM with EDS, HR-TEM, FT-IR, XRD, Raman spectroscopy, and XPS analysis. Formations of CuONPs have been observed by UV-visible absorbance peak at 360.74 nm. The surface morphology of the CuONPs showed the spherical structure and size (~ 68 nm). The EDS spectrum of CuONPs has proved to be the key signals of copper (Cu) and oxygen (O) components. FT-IR analysis, to validate the important functional biomolecules (O-H, C=C, C-H, C-O) are responsible for reduction and stabilization of CuONPs. The monoclinic end-centered crystalline structures of CuONPs were confirmed with XRD planes. The electrochemical oxygen states of the CuONPs have been studied using spectroscopy of the Raman and X-ray photoelectron. After successful preparation, CuONPs examined their antibacterial, anticancer, and photocatalytic activities. Green-fabricated CuONPs were promising antibacterial candidate against human pathogenic gram-negative bacteria Escherichia coli, Vibrio cholerae, Salmonella typhimurium, Klebsiella pneumoniae, Aeromonas hydrophila, and Pseudomonas aeruginosa. CuONPs were demonstrated the excellent anticancer activity against A549 human lung adenocarcinoma cell line. Furthermore, CuONPs exhibited photocatalytic degradation of azo dyes such as eosin yellow (EY), rhodamine 123 (Rh 123), and methylene blue (MB). Biofabricated CuONPs may therefore be an important biomedical research for the aid of bacterial/cancer diseases and photocatalytic degradation of azo dyes.

Carbamazepine at environmentally relevant concentrations caused DNA damage and apoptosis in the liver of Chinese rare minnows (Gobiocypris rarus) by the Ras/Raf/ERK/p53 signaling pathway

To assess genetoxicity and the underlying mechanisms of carbamazepine (CBZ) toxicity in fish, adult Chinese rare minnows (Gobiocypris rarus) were exposed to 1, 10, and 100 μg/L CBZ for 28 d. Comet assays indicated that hepatic DNA damage was significantly increased in groups of minnows exposed to CBZ at all concentrations in a dose-dependent manner compared to those of the control groups (p < 0.05). Liver levels of 8-hydroxydeoxyguanosine (8-OHdG) were significantly increased at 10 and 100 μg/L CBZ (p < 0.05). TUNEL assays indicated that the average apoptotic rates of the livers of female and male minnows were significantly increased following exposure to CBZ at all concentrations for 28 d (p < 0.05). Significant increases in caspase 3 and 9 activities after CBZ exposure at all concentrations and caspase 8 at 10 and 100 μg/L CBZ exposure reflected the presence of mitochondrial apoptosis (p < 0.05). The mRNA levels of gadd45a, mdm2, casp3 and casp9 in female and male minnows exposed to CBZ at all concentrations were significantly increased compared with those in the control groups (p < 0.05). Significant increases in the levels of p21 in female minnows exposed to 1 and 100 μg/L CBZ, p53 in female minnows at all CBZ treatments and bcl2 in male minnows exposed to 1 and 100 μg/L CBZ were observed, indicating p53 pathway activation. The inhibition of ras levels in females and males exposed to CBZ at all concentrations and increased levels of raf1 in males exposed to CBZ at all concentrations indicated Ras/Raf1/MAPK (ERK) activation. Therefore, the present study demonstrates that CBZ at environmentally relevant levels induces DNA damage and apoptosis in Chinese rare minnows by the Ras/Raf/ERK/p53 signaling pathway.

Effects of Myricitrin and Relevant Molecular Mechanisms

In humans, oxidative stress is thought to be involved in the development of Parkinson's disease, Alzheimer's disease, atherosclerosis, heart failure, myocardial infarction and depression. Myricitrin, a botanical flavone, is abundantly distributed in the root bark of Myrica cerifera, Myrica esculenta, Ampelopsis grossedentata, Nymphaea lotus, Chrysobalanus icaco, and other plants. Considering the abundance of its natural sources, myricitrin is relatively easy to extract and purify. Myricitrin reportedly possesses effective anti-oxidative, anti-inflammatory, and anti-nociceptive activities, and can protect a variety of cells from in vitro and in vivo injuries. Therefore, our current review summarizes the research progress of myricitrin in cardiovascular diseases, nerve injury and anti-inflammatory, and provides new ideas for the development of myricitrin.

A comprehensive review of natural products to fight liver fibrosis: Alkaloids, terpenoids, glycosides, coumarins and other compounds

The discovery of drugs to treat liver fibrosis has long been a challenge over the past decades due to its complicated pathogenesis. As a primary approach for drug development, natural products account for 30% of clinical drugs used for disease treatment. Therefore, natural products are increasingly important for their medicinal value in liver fibrosis therapy. In this part of the review, special focus is placed on the effect and mechanism of natural compounds, including alkaloids, terpenoids, glycosides, coumarins and others. A total of 36 kinds of natural compounds demonstrate significant antifibrotic effects in various liver fibrosis models in vivo and in hepatic stellate cells (HSCs) in vitro. Revealing the mechanism will provide further basis for clinical conversion, as well as accelerate drug discovery. The mechanism was further summarized with the finding of network regulation by several natural products, such as oxymatrine, paeoniflorin, ginsenoside Rg1 and taurine. Moreover, there are still improvements needed in investigating clinical efficacy, determining mechanisms, and combining applications, as well as semisynthesis and modification. Therefore, natural products area promising resource for agents that protect against liver fibrosis.

Malvidin induces hepatic stellate cell apoptosis via the endoplasmic reticulum stress pathway and mitochondrial pathway

Blueberries have great beneficial effects due to high level of anthocyanins, especially malvidin. Hepatic stellate cells (HSCs) can be activated and increase excessive extracellular matrix (ECM) components, which play a central role in liver fibrogenesis. Therefore, activated HSC's apoptosis can be induced to recover liver fibrosis. Malvidin's effects on apoptosis in rat activated hepatic stellate T6 cells (HSC-T6) in vitro were investigated here. High concentration of malvidin was found to significantly induce apoptosis, activate caspase-3, increase malondialdehyde, upregulate Bax, but downregulate Bcl-2. Moreover, malvidin upregulated the protein levels of some endoplasmic reticulum stress (ERS)-typical markers, including caspase-12, glucose-regulated protein 78 (GRP78), and CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP), suggesting that malvidin induced HSC apoptosis by the ERS apoptosis pathway as well as the mitochondrial-dependent pathway. These findings indicated that blueberry anthocyanins, especially malvidin, could induce activated hepatic stellate cell apoptosis and might act as one kind of functional food ingredient or a novel nutraceutical beneficial for liver health.

ROS-dependent inhibition of the PI3K/Akt/mTOR signaling is required for Oroxylin A to exert anti-inflammatory activity in liver fibrosis

More and more evidence showed that autophagy is an inflammation-related defense mechanism against a variety of diseases including liver fibrosis. However, the essential mechanisms remain poorly understood. In this study, we sought to elucidate the impact of Oroxylin A on autophagy and further to identify the potential mechanism of its anti-inflammatory activity. We found that Oroxylin A played a critical role in controlling inflammation in murine liver fibrosis. Moreover, Oroxylin A could inhibit the secretion of pro-inflammatory cytokines in activated hepatic stellate cell (HSCs). We previously reported that Oroxylin A can induce autophagy to alleviate the pathological changes of liver fibrosis and the activation of HSC. Here we further revealed that the inhibition of the PI3K/Akt/mTOR signaling was required for Oroxylin A to induce autophagy activation, which may be the underlying mechanism of the anti-inflammatory activity of Oroxylin A. Interestingly, mTOR overexpression completely impaired the Oroxylin A-mediated autophagy activation, and in turn, damaged the anti-inflammatory activity. Importantly, Oroxylin A inhibited PI3K/Akt/mTOR signaling by scavenging reactive oxygen species (ROS). ROS accumulation by buthionine sulfoximine (BSO) could abrogate the Oroxylin A-mediated ROS elimination, the inhibition of PI3K/Akt/mTOR signaling, and anti-inflammatory activities. Overall, our results provided reliable evidence for the molecular mechanism of Oroxylin A-mediated anti-fibrosis activity, and also identified a new target for drug therapy of liver fibrosis.

Conjugation of Ginsenoside with Dietary Amino Acids: A Promising Strategy To Suppress Cell Proliferation and Induce Apoptosis in Activated Hepatic Stellate Cells

Ginseng has been widely used as a functional food in the world because of its well-defined health benefits. Previous studies have confirmed that AD-1, a new ginsenoside derived from ginseng, can ameliorate thioacetamide-induced liver injury and fibrosis in mice. Simultaneously, amino acid supplementation is getting more attention as an important adjuvant therapy in the improvement of hepatopathy. The aim of this study was to conjugate AD-1 with several selected amino acids and investigate the cytotoxicity of the obtained conjugates in activated t-HSC/Cl-6 cells and normal human liver cells (LO2). Structure-activity relationships of conjugates and underlying mechanisms of the effect are also explored. The results indicated that conjugate 7c remarkably inhibited cell proliferation in activated t-HSC/Cl-6 cells (IC₅₀ = 3.8 ± 0.4 μM) and appeared to be nontoxic to LO2. Besides, conjugate 7c had a relatively good plasma stability. Further study demonstrated that inducing S-phase arrest and activation of mitochondrial-mediated apoptosis were included in the mechanisms underlying the efficiency of conjugate 7c. These findings provided further insight into designing functional foods (ginsenoside and amino acid) for the application in prevention or improvement of liver fibrosis.

Tetramethylpyrazine guards against cisplatin-induced nephrotoxicity in rats through inhibiting HMGB1/TLR4/NF-κB and activating Nrf2 and PPAR-γ signaling pathways

Cisplatin-induced acute renal injury is the most common and serious side effect, sometimes requiring discontinuation of the treatment. Thus, the development of new protective strategies is essential. The present study aimed to investigate the potential nephroprotective effect of tetramethylpyrazine (TMP) against acute renal damage induced by cisplatin in rats. Rats were administered 50 and 100 mg/kg TMP intraperitoneally before cisplatin (7 mg/kg). Acute nephrotoxicity was evident in cisplatin-treated rats where relative kidney weight, BUN and serum creatinine were markedly elevated. Cisplatin administration resulted in enhanced oxidative stress, evidenced by depleted GSH level as well as catalase and superoxide dismutase activities. Also, lipid peroxidation was boosted in comparison to the control. This was associated with inhibition of Nrf2 defense pathway. Moreover, cisplatin increased the expression of pro-inflammatory mediators in the kidney tissues. Cisplatin-induced apoptosis was depicted by elevated Bax mRNA expression and caspase-3 activity, as well as decreased Bcl2 mRNA expression. In addition, high mobility group box 1/toll-like receptor 4/nuclear factor-kappa B (HMGB1/TLR4/NF-κB) signaling pathway was significantly upregulated, while peroxisome proliferator-activated receptor-gamma (PPAR-γ) expression was significantly diminished in cisplatin-treated rats. Cisplatin-induced nephrotoxicity, oxidative stress, inflammation, apoptosis and the effect on Nrf2 defense pathway and HMGB1/TLR4/NF-κB as well as PPAR-γ expression were markedly ameliorated by TMP administration. Given the major nephrotoxicity of cisplatin cancer chemotherapy, TMP might be a potential candidate for neoadjuvant chemotherapy due to its antioxidant, anti-inflammatory and anti-apoptotic effects, in addition to its effect on Nrf2, HMGB1/TLR4/NF-κB signaling pathway and PPAR-γ expression.

Betulinic acid attenuates liver fibrosis by inducing autophagy via the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway

The present study was designed to investigate the effects of betulinic acid on human hepatic stellate cells in vitro and C57BL/6 mice in vivo, as well as the signaling pathways involved. In this study, we explored the effects of betulinic acid on expression of alpha smooth muscle actin and autophagy-related proteins. Betulinic acid reduced pathological damage associated with liver fibrosis, as well as serum platelet-derived growth factor and serum hydroxyproline levels. Furthermore, betulinic acid downregulated the expression of alpha smooth muscle actin and type I collagen in mouse liver and upregulated the expression of microtubule-associated protein light chain 3B and autophagy-related gene 7 at the gene and protein levels. LC3II expression was increased and alpha smooth muscle actin expression was decreased in betulinic acid-treated hepatic stellate cells. Interventions with bafilomycin A1 and mCherry-GFP-LC3 adenoviruses promoted the formation of autophagosomes in hepatic stellate cells and the development of autophagic flow. Our study found that mitogen-activated protein kinase/extracellular signal-regulated kinase may be involved in the effects of betulinic acid on liver fibrosis. The present study suggests that betulinic acid has anti-hepatic fibrosis activity by inducing autophagy and could serve as a promising new agent for treating hepatic fibrosis.

Homoisoflavanone-1 isolated from Polygonatum odoratum arrests the cell cycle and induces apoptosis in A549 cells

Homoisoflavanone-1 is a natural compound that may be extracted from the Chinese medicinal herb Polygonatum odoratum, which has pronounced antioxidant activities. The present study reports that homoisoflavanone-1 significantly inhibited tumor cell growth and induced apoptosis in A549 non-small cell lung cancer (NSCLC) cells in a dose-dependent manner. Homoisoflavanone-1 arrested the cell cycle at the G2/M stage, which was associated with an increase in the accumulation of phosphorylated (p-)p38, p38, p53, and p-cyclin dependent kinase (Cdc)2 proteins, as well as a decrease in Cdc2 expression. In addition, treatment with homoisoflavanone-1 increased the levels of active caspase-3 and decreased Poly ADP-ribose polymerase, which was accompanied by a reduction in the B-cell lymphoma-2/Bak ratio and consequently, apoptosis. Furthermore, homoisoflavanone-1 increased the expression of endoplasmic reticulum (ER) stress-related proteins, including PERK, ATF4 and GADD34 in a dose-dependent manner. In conclusion, homoisoflavanone-1 induced apoptosis in A549 cells by regulating the mitochondria-caspase-dependent and ER stress pathways and resulted in G2/M arrest by activating the p38/p53 signaling pathway. These findings suggest that homoisoflavanone-1 extracted from Polygonatum odoratum may function as a cancer-suppressing agent and has potential as a novel therapeutic method against NSCLC.

Neuroprotective Effect of Tetrahedral DNA Nanostructures in a Cell Model of Alzheimer's Disease

Accumulating evidence supports the abnormal deposition of amyloid β-peptide (Aβ) as the main cause of Alzheimer's disease (AD). Therefore, fighting against the formation, deposition, and toxicity of Aβ is a basic strategy for the treatment of AD. In the process of in vitro nerve cell culture, screening out drugs that can antagonize a series of toxic reactions caused by β-amyloid deposition has become an effective method for the follow-up treatment of AD. Our previous studies showed that tetrahedral DNA nanostructures (TDNs) had good biocompatibility and had some positive effects on the biological behavior of cells. In this study, the main aim of our work was to explore the effects and potential mechanism of TDNs in protecting neuronal PC12 cells from the toxicity of Aβ. Our study demonstrated that TDNs can protect and rescue PC12 cell death through Aβ25-35-induced PC12 cell apoptosis. Further studies showed that TDNs significantly improved the apoptosis by affecting the abnormal cell cycle, restoring abnormal nuclear morphology and caspase activity. Western blot analysis showed that TDNs could prevent the damage caused by Aβ deposition by activating the ERK1/2 pathway and thus be a potential therapeutic agent with a neuroprotective effect in Alzheimer's disease. Our finding provides a potential application of TDNs in the prevention and treatment of AD.

Overexpression of the Ubiquilin-4 (UBQLN4) is Associated with Cell Cycle Arrest and Apoptosis in Human Normal Gastric Epithelial Cell Lines GES-1 Cells by Activation of the ERK Signaling Pathway

BACKGROUND Ubiquilin-4 (UBQLN4) is a component of the ubiquitin-proteasome system and regulates the degradation of many proteins implicated in pathological conditions. The aim of this study was to determine the role of UBQLN4 in regulating the proliferation and survival of the normal gastric epithelial cell line GES-1. MATERIAL AND METHODS We constructed GES-1 lines stably overexpressing UBQLN4 by lentiviral infection. Cell proliferation, apoptosis, and the cell cycle were analyzed using the MTT assay and flow cytometric assays. Phosphorylation of ERK, JNK, p38, and expression of cyclin D1 were detected by western blot analysis. RESULTS Overexpression of UBQLN4 significantly reduced proliferation and induced G2/M phase arrest and apoptosis in GES-1 cells. Moreover, upregulation of UBQLN4 increased the expression of cyclin D1 and phosphorylated ERK, but not JNK or p38. CONCLUSIONS These data suggest that UBQLN4 may induce cell cycle arrest and apoptosis via activation of the ERK pathway and upregulation of cyclin D1 in GES-1 cells.

Autophagy inhibition attenuates the induction of anti-inflammatory effect of catalpol in liver fibrosis

Autophagy has been regarded as an inflammation-associated defensive mechanism against chronic liver disease, which has been highlighted as a novel therapeutic target for the treatment of liver fibrosis. We herein aimed to study the effects of catalpol on liver fibrosis in vivo and in vitro, and to elucidate the role of autophagy in catalpol-induced anti-inflammation. Catalpol protected the liver against CCl₄-induced injury, as evidenced by mitigated hepatic steatosis, necrosis, and fibrotic septa. Catalpol decreased the serum levels of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase and bilirubin as well as the liver/body weight ratio. Masson and sirius red staining along with hydroxyproline detection showed that catalpol decreased collagen deposition significantly compared to that of the model group. Catalpol inhibited CCl₄-induced liver fibrosis, manifested as decreased expressions of α-SMA, fibronectin and α1(I)-procollagen at both transcriptional and translational levels. Inflammatory factors, such as IL-1β, TNF-α, IL-18, IL-6 and COX-2, were significantly elevated in rats receiving CCl₄ and down-regulated by catalpol in a dose-dependent manner in vivo. Western blot and immunofluorescence assay revealed that catalpol activated the autophagy of rats with CCl₄-caused liver fibrosis, as indicated by up-regulation of LC3-II and beclin1 and down-regulation of P62. The results of in vitro experiments were consistent. Interestingly, inhibition or depletion of autophagy by LY294002 or Atg5 siRNA significantly attenuated catalpol-induced anti-inflammatory effects on activated hepatic stellate cells in vitro. In conclusion, catalpol relieved liver fibrosis mainly by inhibiting inflammation, and autophagy inhibition attenuated the catalpol-induced anti-inflammatory effect on liver fibrosis.

Ligand Activation of PPARγ by Ligustrazine Suppresses Pericyte Functions of Hepatic Stellate Cells via SMRT-Mediated Transrepression of HIF-1α

Rationale: Hepatic stellate cells (HSCs) are liver-specific pericytes regulating vascular remodeling during hepatic fibrosis. Here, we investigated how ligustrazine affects HSC pericyte functions.

Methods: Rat HSC-T6 and human HSC-LX2 cells were cultured, and multiple molecular experiments including real-time PCR, Western blot, flow cytometry, immunofluorescence, electrophoretic mobility shift assay and co-immunoprecipitation were used to elucidate the underlying mechanisms. Molecular simulation and site-directed mutagenesis were performed to uncover the target molecule of ligustrazine. Rats were intoxicated with CCl₄ for evaluating ligustrazine's effects in vivo.

Results: Ligustrazine inhibited angiogenic cytokine production, migration, adhesion and contraction in HSCs, and activated PPARγ. Selective PPARγ inhibitor GW9662 potently abrogated ligustrazine suppression of HSC pericyte functions. Additionally, HIF-1α inhibitor PX-478 repressed HSC pericyte functions, and ligustrazine inhibited the transcription of HIF-1α, which was diminished by GW9662. Moreover, ligustrazine downregulation of HIF-1α was rescued by knockdown of SMRT, and ligustrazine increased PPARγ physical interaction with SMRT, which was abolished by GW9662. These findings collectively indicated that activation of PPARγ by ligustrazine led to transrepression of HIF-1α via a SMRT-dependent mechanism. Furthermore, molecular docking evidence revealed that ligustrazine bound to PPARγ in a unique double-molecule manner via hydrogen bonding with the residues Ser289 and Ser342. Site-directed mutation of Ser289 and/or Ser342 resulted in the loss of ligustrazine transrepression of HIF-1α in HSCs, indicating that interactions with both the residues were indispensable for ligustrazine effects. Finally, ligustrazine improved hepatic injury, angiogenesis and vascular remodeling in CCl₄-induced liver fibrosis in rats.

Conclusions: We discovered a novel ligand activation pattern for PPARγ transrepression of the target gene with therapeutic implications in HSC pericyte biology and liver fibrosis.

A novel agent exerts antitumor activity in breast cancer cells by targeting mitochondrial complex II

The mitochondrial respiratory chain, including mitochondrial complex II, has emerged as a potential target for cancer therapy. In the present study, a novel conjugate of danshensu (DSS) and tetramethylpyrazine (TMP), DT-010, was synthesized. Our results showed that DT-010 is more potent than its parental compounds separately or in combination, in inhibiting the proliferation of MCF-7 and MDA-MB-231 cells by inducing cytotoxicity and promoting cell cycle arrest. It also inhibited the growth of 4T1 breast cancer cells in vivo. DT-010 suppressed the fundamental parameters of mitochondrial function in MCF-7 cells, including basal respiration, ATP turnover, maximal respiration. Treatment with DT-010 in MCF-7 and MDA-MB-231 cells resulted in the loss of mitochondrial membrane potential and decreased ATP production. DT-010 also promoted ROS generation, while treatment with ROS scavenger, NAC (N-acetyl-L-cysteine), reversed DT-010-induced cytotoxicity. Further study showed that DT-010 suppressed succinate-induced mitochondrial respiration and impaired mitochondrial complex II enzyme activity indicating that DT-010 may inhibit mitochondrial complex II. Overall, our results suggested that the antitumor activity of DT-010 is associated with inhibition of mitochondrial complex II, which triggers ROS generation and mitochondrial dysfunction in breast cancer cells.

Antihepatocellular Carcinoma Potential of Tetramethylpyrazine Induces Cell Cycle Modulation and Mitochondrial-Dependent Apoptosis: Regulation of p53 Signaling Pathway in HepG2 Cells In Vitro

Tetramethylpyrazine (TMP) was originally isolated from a traditional Chinese herbal medicine, Ligusticum chuanxiong In the present study, TMP exhibits potent antitumor activities in vitro. However, the molecular mechanisms remain to be defined. Hence, this study aims to investigate the antiproliferative and apoptotic effects of TMP on HepG2 and elucidate the underlying mechanisms. Analyses using Cell Counting Kit-8 and real-time cell analyzer indicated that TMP significantly inhibited HepG2 cell proliferation. We also observed that TMP induced cell cycle arrest at the G0/G1 checkpoint and apoptosis, using flow cytometry and high-content screening. Furthermore, our results predicted that TMP could directly decrease mitochondrial membrane potential (Δψm), increase the release of cytochrome c, and increase caspase activation, indicating that mitochondrial pathway apoptosis could be the mechanism for TMP within HepG2 cells. Moreover, TMP altered expression of p53 and the Bcl-2/Bax protein ratio, which revealed that TMP induced cell cycle arrest and caspase-dependent mitochondrial apoptosis in HepG2 cells in vitro. These studies provided mechanistic insights into the antitumor properties of TMP, which may be explored as a potential option for treatment of hepatocellular carcinoma.

Evaluation of the antioxidant property and effects in Caenorhabditis elegans of Xiangxi flavor vinegar, a Hunan local traditional vinegar

Xiangxi flavor vinegar (XV) is one of Hunan Province's traditional fermented vinegars. It is produced from herb, rice, and spring water with spontaneous liquid-state fermentation techniques. In this study, we investigated the antioxidant property of XV by analyzing its antioxidant compounds, its free radical scavenging property in vitro and in vivo, and its effects on antioxidant enzyme activity and apoptosis in Caenorhabditis elegans. The results showed that XV is rich in antioxidants. In particular, ligustrazine reached 6.431 μg/ml. The in vitro 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH^•), hydroxyl radical (^•OH), and superoxide anion radical (O₂^•-) scavenging rates of XV were 95.85%, 97.22%, and 63.33%, respectively. The reactive oxygen species (ROS) content in XV-treated C. elegans decreased significantly (P<0.01) compared to the control group. Glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) activities were remarkably increased (P<0.01) in C. elegans after XV treatment. In addition, XV could upregulate CED-9 protein expression and downregulate CED-3 protein expression in C. elegans. These results prove that XV is rich in antioxidants and scavenges radicals in vitro efficiently. XV inhibits apoptosis in C. elegans probably by scavenging ROS and increasing the activities of its antioxidant enzymes.

Effect of tetramethylpyrazine combined with cisplatin on VEGF, KLF4 and ADAMTS1 in Lewis lung cancer mice

OBJECTIVE

To further explore the function of combine use of tetramethylpyrazine (TMP) and cisplatin (DDP) in lung carcinoma.

METHODS

We used the combination drug to treat Lewis lung cancer mice, investigated the expression level of vascular endothelial growth factor (VEGF), Kruppel-like factor 4 (KLF4) and A disintegrin and metalloproteinase with thrombospondin motifs 1 (ADAMTS1) and to further explore the inhibitory effects and potential mechanism of TMP combined with DDP on tumor angiogenesis.

RESULTS

The tumor growth was suppressed in TMP group, DDP group and TMP combined with DDP group. Furthermore, the weights and volume of tumor, the expression level of VEGF, KLF4 and ADAMTS1 were found significantly changed between experiment group and control group. These findings suggest that TMP with DDP had additional or synergistic effects to inhibit the tumor growth effectively, might be achieved through reducing the expression of angiogenesis promoting factor VEGF and increasing expression of angiogenesis inhibitors KLF4 and ADAMTS1.

CONCLUSION

KLF4 and ADAMTS1 may be synergically involved in the angiogenesis in mouse Lewis lung cancer through the different signal ways.

Effect of tetramethylpyrazine (TMP) on Ca2+ signal transduction and cell viability in a model of renal tubular cells

Tetramethylpyrazine (TMP) is a compound purified from herb. Its effect on Ca²⁺ concentrations ([Ca²⁺ ]_i ) in renal cells is unclear. This study examined whether TMP altered Ca²⁺ signaling in Madin-Darby canine kidney (MDCK) cells. TMP at 100-800 μM induced [Ca²⁺ ]_i rises, which were reduced by Ca²⁺ removal. TMP induced Mn²⁺ influx implicating Ca²⁺ entry. TMP-induced Ca²⁺ entry was inhibited by 30% by modulators of protein kinase C (PKC) and store-operated Ca²⁺ channels. Treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor 2,5-di-tert-butylhydroquinone (BHQ) inhibited 93% of TMP-evoked [Ca²⁺ ]_i rises. Treatment with TMP abolished BHQ-evoked [Ca²⁺ ]_i rises. Inhibition of phospholipase C (PLC) abolished TMP-induced responses. TMP at 200-1000 μM decreased viability, which was not reversed by pretreatment with the Ca²⁺  chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester. Together, in MDCK cells, TMP induced [Ca²⁺ ]_i rises by evoking PLC-dependent Ca²⁺ release from endoplasmic reticulum and Ca²⁺ entry via PKC-sensitive store-operated Ca²⁺ entry. TMP also caused Ca²⁺ -independent cell death.

The aflatoxin B1 -fumonisin B1 toxicity in BRL-3A hepatocytes is associated to induction of cytochrome P450 activity and arachidonic acid metabolism

Human oral exposure to aflatoxin B₁ (AFB₁ ) and fumonisin B₁ (FB₁ ) is associated with increased hepatocellular carcinoma. Although evidence suggested interactive AFB₁ -FB₁ hepatotoxicity, the underlying mechanisms remain mostly unidentified. This work was aimed at evaluating the possible AFB₁ -FB₁ interplay to induce genetic and cell cycle toxicities in BRL-3A rat hepatocytes, reactive oxygen species (ROS) involvement, and the AFB₁ metabolizing pathways cytochrome P450 (CYP) and arachidonic acid (ArAc) metabolism as ROS contributors. Flow cytometry of stained BRL-3A hepatocytes was used to study the cell cycle (propidium iodide), ROS intracellular production (DCFH-DA, HE, DAF-2 DA), and phospholipase A activity (staining with bis-BODIPY FL C11-PC). The CYP1A activity was assessed by the 7-ethoxyresorufin-O-deethylase (EROD) assay. Despite a 48-h exposure to FB₁ (30 μM) not being genotoxic, the AFB₁ (20 μM)-induced micronucleus frequency was overcome by the AFB₁ -FB₁ mixture (MIX), presumably showing toxin interaction. The mycotoxins blocked G1/S-phase, but only MIX caused cell death. Overall, the oxidative stress led these alterations as the pretreatment with N-acetyl-l-cysteine reduced such toxic effects. While AFB₁ had a major input to the MIX pro-oxidant activity, with CYP and ArAc metabolism being ROS contributors, these pathways were not involved in the FB₁ -elicited weak oxidative stress. The MIX-induced micronucleus frequency in N-acetyl-l-cysteine pretreated cells was greater than that caused by AFB₁ without antioxidants, suggesting enhanced AFB₁ direct genotoxicity probably owing to the higher CYP activity and ArAc metabolism found in MIX. The metabolic pathways modulation by AFB₁ -FB₁ mixtures could raise its hepatocarcinogenic properties.

Tetramethylpyrazine blocks TFAM degradation and up-regulates mitochondrial DNA copy number by interacting with TFAM

The natural small molecule compound: 2,3,5,6-tetramethylpyrazine (TMP), is a major component of the Chinese medicine Chuanxiong, which has wide clinical applications in dilating blood vessels, inhibiting platelet aggregation and treating thrombosis. Recent work suggests that TMP is also an antitumour agent. Despite its chemotherapeutic potential, the mechanism(s) underlying TMP action are unknown. Herein, we demonstrate that TMP binds to mitochondrial transcription factor A (TFAM) and blocks its degradation by the mitochondrial Lon protease. TFAM is a key regulator of mtDNA replication, transcription and transmission. Our previous work showed that when TFAM is not bound to DNA, it is rapidly degraded by the ATP-dependent Lon protease, which is essential for mitochondrial proteostasis. In cultured cells, TMP specifically blocks Lon-mediated degradation of TFAM, leading to TFAM accumulation and subsequent up-regulation of mtDNA content in cells with substantially low levels of mtDNA. In vitro protease assays show that TMP does not directly inhibit mitochondrial Lon, rather interacts with TFAM and blocks degradation. Pull-down assays show that biotinylated TMP interacts with TFAM. These findings suggest a novel mechanism whereby TMP stabilizes TFAM and confers resistance to Lon-mediated degradation, thereby promoting mtDNA up-regulation in cells with low mtDNA content.

Influence of long-term, high-dose dexamethasone administration on proliferation and apoptosis in porcine hepatocytes

The aim of this study was to examine the influence of long-term, high-dose dexamethasone administration on the liver, with particular emphasis on hepatocyte proliferation and apoptosis, using a swine model. The study included 48 large, female Polish breed pigs aged 3months (weighing ca. 30kg) divided into groups I (control; n=24) and II (dexamethasone; n=24) that receiving intra-muscular injections of monosodium phosphate dexamethasone for 29days. The pigs were euthanized on days subsequent to the experiment. Immediately after the euthanasia, the pig livers were sampled, fixed, and processed routinely for histopathology, histochemistry, and immunohistochemistry (for proliferating cell nuclear antigen, Bcl-2, and caspase-3). Apoptosis was visualized by terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL). Dexamethasone administration gradually caused hepatocyte glycogen degeneration and finally lipid degeneration, accompanied by sinusoid and central vein dilatation and nuclear chromatin condensation. The proliferating cell nuclear antigen index, mean number of argyrophilic nucleolar organizer regions and proliferation index of argyrophilic nucleolar organizer regions were lower, while Bcl-2 expression was higher in group II compared with group I. The results from this study suggest that safe high-dose dexamethasone administration time is difficult to establish. Long-term, high-dose dexamethasone administration can cause pronounced morphological changes in hepatocytes by diminishing their transcriptional and proliferation activity but also protects them from apoptosis by potentially affecting Bcl-2 expression.

Catalpol protects glucose-deprived rat embryonic cardiac cells by inducing mitophagy and modulating estrogen receptor

Catalpol, a bioactive component from Rehmannia glutinosa (Di Huang), has been widely used to protect cardiomyocytes against myocardial ischemia. The aim of the present study was to investigate the anti-apoptotic and anti-oxidative effects of Catalpol on glucose-starved H9c2 cells for cardio-protection and to elucidate the underlying mechanisms. Here, we showed that Catalpol protected the glucose-starved H9c2 cells through reducing apoptosis and attenuating oxidative damage. Moreover, the increases of autophagic lysosomes, LC3, autophagic flux and autophagic vacuole were observed in Catalpol-treated cells using flow cytometer and fluorescence microscope. Western blotting analyses showed that the autophagy-related proteins (LC3, Beclin1 and ULK) were markedly increased in Catalpol-treated cells, suggesting that Catalpol up-regulated autophagy in glucose starved H9c2 cells. Mechanistic investigations revealed that the autophagy inhibitor 3-MA markedly abrogated Catalpol's anti-apoptotic and anti-oxidative effects and prevented Catalpol-induced mitophagy. Furthermore, the estrogen receptor inhibitor tamoxifen significantly abolished Catalpol up-regulation of mitophagic related proteins (LC3, Beclin 1, p62, ATG5). Collectively, these data revealed that Catalpol inhibited apoptosis and oxidative stress in glucose-deprived H9c2 cell through promoting cell mitophagy and modulating estrogen receptor, supporting the notion that Catalpol could be a novel drug candidate against myocardial ischemia for the treatment of cardiovascular diseases.

Canonical hedgehog signalling regulates hepatic stellate cell-mediated angiogenesis in liver fibrosis

BACKGROUND AND PURPOSE

Hepatic stellate cells (HSCs) are liver-specific pericytes regulating angiogenesis during liver fibrosis. We aimed to elucidate the mechanisms by which hedgehog signalling regulated HSC angiogenic properties and to validate the therapeutic implications.

EXPERIMENTAL APPROACH

Rats and mice were treated with carbon tetrachloride for in vivo evaluation of hepatic angiogenesis and fibrotic injury. Diversified molecular approaches including real-time PCR, Western blot, luciferase reporter assay, chromatin immunoprecipitation, electrophoretic mobility shift assay and co-immunoprecipitation were used to investigate the underlying mechanisms in vitro.

KEY RESULTS

Angiogenesis was concomitant with up-regulation of Smoothened (SMO) and hypoxia inducible factor-1α (HIF-1α) in rat fibrotic liver. The SMO inhibitor cyclopamine and Gli1 inhibitor GANT-58 reduced expression of VEGF and angiopoietin 1 in HSCs and suppressed HSC tubulogenesis capacity. HIF-1α inhibitor PX-478 suppressed HSC angiogenic behaviour, and inhibition of hedgehog decreased HIF-1α expression. Furthermore, heat shock protein 90 (HSP90) was characterized as a direct target gene of canonical hedgehog signalling in HSCs. HSP90 inhibitor 17-AAG reduced HSP90 binding to HIF-1α, down-regulated HIF-1α protein abundance and decreased HIF-1α binding to DNA. 17-AAG also abolished 1-stearoyl-2-arachidonoyl-sn-glycerol (SAG) (a SMO agonist)-enhanced HSC angiogenic properties. Finally, the natural compound ligustrazine was found to inhibit canonical hedgehog signalling leading to suppressed angiogenic properties of HSCs in vitro and ameliorated liver fibrosis and sinusoidal angiogenesis in mice.

CONCLUSION AND IMPLICATIONS

We have provided evidence that the canonical hedgehog pathway controlled HSC-mediated liver angiogenesis. Selective inhibition of HSC hedgehog signalling could be a promising therapeutic approach for hepatic fibrosis.

ROS-JNK1/2-dependent activation of autophagy is required for the induction of anti-inflammatory effect of dihydroartemisinin in liver fibrosis

Accumulating evidence identifies autophagy as an inflammation-related defensive mechanism against diseases including liver fibrosis. Therefore, autophagy may represent a new pharmacologic target for drug development to treat liver fibrosis. In this study, we sought to investigate the effect of dihydroartemisinin (DHA) on autophagy, and to further examine the molecular mechanisms of DHA-induced anti-inflammatory effects. We found that DHA appeared to play an essential role in controlling excessive inflammation. DHA suppressed inflammation in rat liver fibrosis model and inhibited the expression of proinflammatory cytokines in activated hepatic stellate cells (HSCs). Interestingly, DHA increased the autophagosome generation and autophagic flux in activated HSCs, which is underlying mechanism for the anti-inflammatory activity of DHA. Autophagy depletion impaired the induction of anti-inflammatory effect of DHA, while autophagy induction showed a synergistic effect with DHA. Importantly, our study also identified a crucial role for reactive oxygen species (ROS) in the facilitation of DHA-induced autophagy. Antioxidants, such as glutathione and N-acetyl cysteine, significantly abrogated ROS production, and in turn, prevented DHA-induced autophagosome generation and autophagic flux. Besides, we found that c-Jun N-terminal kinase1/2 (JNK1/2) was a downstream signaling molecule of ROS that mediated the induction of autophagy by DHA. Down-regulation of JNK1/2 activity, using selective JNK1/2 inhibitor (SP600125) or siJNK1/2, led to an inhibition of DHA-induced autophagy. Overall, these results provide novel implications to reveal the molecular mechanism of DHA-induced anti-inflammatory effects, by which points to the possibility of using DHA based proautophagic drugs for the treatment of inflammatory diseases.

Ligustrazine-Oleanolic Acid Glycine Derivative, G-TOA, Selectively Inhibited the Proliferation and Induced Apoptosis of Activated HSC-T6 Cells

Hepatic fibrosis is a naturally occurring wound-healing reaction, with an imbalance of extracellular matrix (ECM) during tissue repair response, which can further deteriorate to hepatocellular carcinoma without timely treatment. Inhibiting activated hepatic stellate cell (HSC) proliferation and inducing apoptosis are the main methods for the treatment of liver fibrosis. In our previous study, we found that the TOA-glycine derivative (G-TOA) had exhibited more significant inhibitory activity against HepG2 cells and better hydrophilicity than TOA, ligustrazine (TMP), and oleanolic acid (OA). However, inhibiting activated HSC proliferation and inducing apoptosis by G-TOA had not been reported. In this paper, the selective cytotoxicity of G-TOA was evaluated on HSC-T6 cells and L02 cells, and apoptosis mechanisms were explored. It was found that G-TOA could selectively inhibit the proliferation of activated HSC-T6 cells, induce morphological changes, early apoptosis, and mitochondrial membrane potential depolarization, increase intracellular free calcium levels, downregulate the expression of NF-κB/p65 and COX-2 protein, and decrease the ratio of Bcl-2/Bax, thereby inducing HSC-T6 cell apoptosis. Thence, G-TOA might be a potential antifibrosis agent for the therapy of hepatic fibrosis, provided that it exerts anti-fibrosis effects on activated HSC-T6 cells.

Effects of recombinant human adenovirus-p53 on the regression of hepatic fibrosis

Hepatic fibrosis is a scarring process that may progress to hepatic cirrhosis and even hepatic carcinoma if left untreated. Hepatic stellate cells (HSCs) play essential roles in the development of hepatic fibrosis. The tumor suppressor protein p53 is a transcription factor that is involved in cell proliferation, cell cycle regulation, apoptosis and DNA repair. Recombinant human adenovirus-p53 (Ad-p53) has been demonstrated to act as a promising antitumor gene therapy in various types of cancer. However, there is limited infomration regarding the therapeutic effect of Ad-p53 on the regression of hepatic fibrosis. In order to examine the underlying molecular mechanism responsible for the effects of Ad-p53 on HSCs, a rat model of hepatic fibrosis was established and HSC-T₆ cells were cultured under different conditions. The expression of p53, transforming growth factor (TGF-β1) and α-smooth muscle actin (α-SMA), which is a marker of activated HSCs, was detected by immunohistochemical assays and RT-qPCR. In vitro, five different concentrations (1×10⁶, 5×10⁶, 1×10⁷, 2×10⁷ and 5×10⁷ PFU/ml) of Ad-p53 were selected for use in the MTT assay to analyze the proliferation of HSCs at 0, 24, 48 and 72 h. Flow cytometric analysis was applied to determine the effect of three different concentrations of Ad-p53 (5×10⁶, 1×10⁷ and 2×10⁷ PFU/ml) on the cell cycle and the apoptosis of HSC-T₆ cells at 24 and 48 h. The results of immunohistochemical studies and RT-qPCR showed that Ad-p53 upregulated the expression of p53, and downregulated the expression of TGF-β1 and α-SMA. The MTT assay revealed that when treated with various doses of Ad-p53, the proliferation of HSCs was inhibited within a certain range of concentrations and time periods. Analysis of flow cytometric data showed that Ad-p53 arrested the cell cycle in G1 phase and significantly induced apoptosis. Taken together, these findings suggest that Ad-p53 promotes apoptosis and inhibits the proliferation of HSCs in a time- and dose-dependent manner by modulating the expression of p53, TGF-β1 and α-SMA.

Inhibiting miR-21 attenuates experimental hepatic fibrosis by suppressing both the ERK1 pathway in HSC and hepatocyte EMT

MicroRNA-21 (miR-21) has emerged as a critical regulatory molecule and an important serum marker in hepatic fibrogenesis. The aim of the present study was to investigate the role of inhibiting miR-21 on hepatic fibrosis treatment. Serum miR-21 levels in 60 healthy individuals and 180 patients with different stages of liver cirrhosis were examined, miR-21 levels in normal or cirrhotic human liver tissues (n=10 each) were also detected. An adenoviral vector (Ad-TuD-21) carrying the sponging ToughDecoy (TuD)-RNA sequence against miR-21 was constructed to reduce miR-21 expression efficiently in vitro and in vivo Histological and immunohistological examinations were performed to evaluate the inhibitory effects and mechanism of Ad-TuD-21 delivery into carbon tetrachloride (CCl4) induced hepatic fibrosis rats by targeting extracellular signal-regulated kinase 1 (ERK1) signalling in hepatic stellate cells (HSC) and hepatocyte epithelial-mesenchymal transition (EMT). Our results revealed that enhanced miR-21 levels in cirrhotic patients were related to the severity and activity of liver cirrhosis. Ad-TuD-21 administered to liver fibrosis rats could remarkably suppress profibrotic gene expression, cause histological improvements in liver and attenuate hepatic fibrosis significantly. More importantly, after Ad-TuD-21 treatment, inhibition of both the ERK1 signalling pathway in HSC and hepatocyte EMT was confirmed, which paralleled the enhancement of miR-21 target genes-sprouty2 (SPRY2) and hepatocyte nuclear factor 4α (HNF4α)-expression in vivo These data demonstrated that miR-21 is a key regulator to promote hepatic fibrogenesis, and sponging miR-21 expression may present a novel potentially therapeutic option for hepatic fibrosis.

ALEX1 Regulates Proliferation and Apoptosis in Breast Cancer Cells

BACKGROUND

Arm protein lost in epithelial cancers, on chromosome X (ALEX) is a novel subgroup within the armadillo (ARM) family, which has one or two ARM repeat domains as opposed to more than six-thirteen repeats in the classical Armadillo family members.

MATERIALS AND METHODS

In the study, we explore the biological functions of ALEX1 in breast cancer cells. Overexpression of ALEX1 and silencing of ALEX1 were performed with SK-BR3 and MCF-7 cell lines. Cell proliferation and colony formation assays, along with flow cytometry, were carried out to evaluate the roles of ALEX1.

RESULTS

ALEX1 overexpression in SK-BR3 breast cancer cells inhibited proliferation and induced apoptosis. Furthermore, depletion of ALEX1 in MCF-7 breast cancer cells increased proliferation and inhibited apoptosis. Additional analyses demonstrated that the overexpression of ALEX1 activated the intrinsic apoptosis cascades through up-regulating the expression of Bax, cytosol cytochrome c, active caspase-9 and active caspase-3 and down-regulating the levels of Bcl-2 and mitochondria cytochrome c. Simultaneouly, silencing of ALEX1 inhibited intrinsic apoptosis cascades through down-regulating the expression of Bax, cytosol cytochrome c, active caspase-9, and active caspase-3 and up-regulating the level of Bcl-2 and mitochondria cytochrome c.

CONCLUSIONS

Our data suggest that ALEX1 as a crucial tumor suppressor gene has been involved in cell proliferation and apoptosis in breast cancer, which may serve as a novel candidate therapeutic target.

Flavones inhibit breast cancer proliferation through the Akt/FOXO3a signaling pathway

BACKGROUND

Flavones found in plants display various biological activities, including anti-allergic, anti-viral, anti-inflammatory, anti-oxidation, and anti-tumor effects. In this study, we investigated the anti-tumor effects of flavone, apigenin and luteolin on human breast cancer cells.

METHODS

The anti-cancer activity of flavone, apigenin and luteolin was investigated using the MTS assay. Apoptosis was analyzed by Hoechst 33342 staining, flow cytometry and western blot. Cell migration was determined using the culture inserts and xCELLigence real-time cell analyzer instrument equipped with a CIM-plate 16. Real-time quantitative PCR and western blot were used to determine the signaling pathway elicited by flavone, apigenin and luteolin.

RESULTS

Flavone, apigenin and luteolin showed potent inhibitory effects on the proliferation of Hs578T, MDA-MB-231 and MCF-7 breast cancer cells in a concentration and time-dependent manner. The ability of flavone, apigenin and luteolin to inhibit the growth of breast cancer cells through apoptosis was confirmed by Hoechst33342 staining and the induction of sub-G1 phase of the cell cycle. Flavone, apigenin and luteolin induced forkhead box O3 (FOXO3a) expression by inhibiting Phosphoinositide 3-kinase (PI3K) and protein kinase B (PKB)/Akt. This subsequently elevated the expression of FOXO3a target genes, including the Cyclin-dependent kinase inhibitors p21Cip1 (p21) and p27kip1 (p27), which increased the levels of activated poly(ADP) polymerase (PARP) and cytochrome c.

CONCLUSION

Taken together, these data demonstrated that flavone, apigenin and luteolin induced cell cycle arrest and apoptosis in breast cancer cells through inhibiting PI3K/Akt activation and increasing FOXO3a activation, which suggest that flavone, apigenin and luteolin will be the potential leads for the preventing and treating of breast cancer.

Overexpression of MCPH1 inhibits uncontrolled cell growth by promoting cell apoptosis and arresting the cell cycle in S and G2/M phase in lung cancer cells

Microcephalin (MCPH1/BRIT1) is a large nuclear protein that is involved in the early cellular response to DNA damage, the expression of which is reduced in a variety of types of human tumors. A recent study by our group demonstrated that MCPH1 expression is markedly decreased in lung cancer. However, it remains unclear whether inducing the expression of MCPH1 may ameliorate lung cancer, and, if so, which mechanisms underlie this process. The results of the present study demonstrated that MCPH1 expression was downregulated in lung cancer tissues compared with that in normal lung tissues. Furthermore, MCPH1 overexpression in A549 non-small cell lung carcinoma cells, successfully inhibited cell proliferation via arrest of the cell cycle in the S and G2/M phases. In addition, MCPH1 overexpression promoted cell apoptosis, in association with a significant increase in the quantities of Bax and active caspase-3, as well as a decrease in the level of Bcl-2. In conclusion the present results indicated that MCPH1 is involved in the regulation of apoptosis and entry into mitosis, suggesting that MCPH1 may function as a tumor suppressor and that it may be important in the pathogenesis of lung cancer.

The Ras/Raf/Erk Pathway Mediates the Subarachnoid Hemorrhage-Induced Apoptosis of Hippocampal Neurons Through Phosphorylation of p53

Apoptosis plays a crucial role in the pathogenesis of early brain injury (EBI) following subarachnoid hemorrhage (SAH). However, the exact molecular mechanisms underlying neuronal apoptosis in EBI after SAH have not been fully elucidated. The present study showed that EBI induced significantly neuronal apoptosis activation of Ras/Raf/Erk signals in hippocampus after SAH. Intracisternal administration of PD98059, an inhibitor of Erk1/2, decreased the hippocampal neuronal apoptosis and alleviated the cognitive deficits induced by SAH. Interestingly, an increase in phosphorylation of p53 was paralleled with p-Erk, and PD98059 also blocked the level of p-p53. In primary cultures, oxyhemoglobin (OxyHb) treatment significantly increased p-Erk, p-p53, and apoptosis, which was used to mimic the pathological injury of SAH. Both p53 small interfering RNA (siRNA) and PD98059 reduced the OxyHb-induced apoptosis. Moreover, PD98059 significantly decreased the levels of p-Erk and p-p53; however, p53 siRNA had little effect on the level of p-Erk. Taken together, our study implicates that the Ras/Raf/Erk signals contribute to neuronal death through the phosphorylation of p53 in hippocampus after SAH and also suggests Erk/p53 as a potential target for clinical drug treatment of SAH.

Tetramethylpyrazine Inhibits Activation of Hepatic Stellate Cells through Hedgehog Signaling Pathways In Vitro

Background and Aim. Tetramethylpyrazine (TMP), a major alkaloid isolated from Ligusticum chuanxiong, has been reported in hepatic fibrosis models. However, the action mechanism remains unclear. In the present study, effects of tetramethylpyrazine (TMP) against hepatic stellate cell (HSC) activation as well as the possible mechanisms were evaluated. Methods. Western blot assay was used to detect TMP effects on protein expression of Smo, Patched, Hhip, and Gli and to investigate the effects of TMP on Cyclin D1, Cyclin E1, CDK2, Bcl-2, Bax, and caspase expression with cyclopamine supplementation. Results. Our results showed that TMP significantly inhibits the expression of Cyclin D1, Cyclin E1, and Cyclin-dependent kinase CDK2 and changes the HSC cycle by inhibiting the proliferation of HSC. Moreover, TMP has also been shown to decrease the expression of Bcl-2 and increase the expression of Bax in HSC-T6 cells. Furthermore, TMP can inhibit the expression of connective tissue growth factor (CTGF), and the inhibitory effect was intensified after the application of joint treatment with TMP and cyclopamine. Conclusion. TMP may be an effective Hh signaling pathway inhibitor for hepatic fibrosis treatment.

Iso-suillin isolated from Suillus luteus, induces G1 phase arrest and apoptosis in human hepatoma SMMC-7721 cells

Iso-suillin, a natural product isolated from Suillus luteus, has been shown to inhibit the growth of some cancer cell lines. However, the molecular mechanisms of action of this compound are poorly understood. The purpose of this study was to investigate how iso-suillin inhibits proliferation and induces apoptosis in a human hepatoma cell line (SMMC-7721). We demonstrated the effects of iso-suillin on cell proliferation and apoptosis in SMMC-7721 cells, with no apparent toxicity in normal human lymphocytes, using colony formation assays and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analysis. Western blotting was used to examine the expression of G1 phase-regulated and apoptosis-associated protein levels in iso-suillin treated SMMC-7721 cells. The results indicated that iso-suillin significantly decreased viability, induced G1 phase arrest and triggered apoptosis in SMMC-7721cells. Taken together, these results suggest the potential of iso-suillin as a candidate for liver cancer treatment.