Recent Advances in Carbon-Based Iron Catalysts for Organic Synthesis.

Carbon-based iron catalysts combining the advantages of iron and carbon material are efficient and sustainable catalysts for green organic synthesis. The present review summarizes the recent examples of carbon-based iron catalysts for organic reactions, including reduction, oxidation, tandem and other reactions. In addition, the introduction strategies of iron into carbon materials and the structure and activity relationship (SAR) between these catalysts and organic reactions are also highlighted. Moreover, the challenges and opportunities of organic synthesis over carbon-based iron catalysts have also been addressed. This review will stimulate more systematic and in-depth investigations on carbon-based iron catalysts for exploring sustainable organic chemistry.

Caspase-4/11 is critical for angiogenesis by repressing Notch1 signalling via inhibiting γ-secretase activity.

BACKGROUND AND PURPOSE: Notch1 activation mediated by γ-secretase is critical for angiogenesis. GeneCards database predicted that Caspase-4 (CASP4, with murine ortholog CASP11) interacts with presenilin-1, the catalytic core of γ-secretase. Therefore, we investigated the role of CASP4/11 in angiogenesis. EXPERIMENTAL APPROACH: In vivo, we studied the role of Casp11 in several angiogenesis mouse models using Casp11 wild-type and knockout mice. In vitro, we detected the effects of CASP4 on endothelial functions and Notch signalling by depleting or overexpressing CASP4 in human umbilical vein endothelial cells (HUVECs). The functional domain responsible for the binding of CASP4 and presenilin-1 was detected by mutagenesis and co-immunoprecipitation. KEY RESULTS: Casp11 deficiency impaired adult angiogenesis in ischaemic hindlimbs, melanoma xenografts and Matrigel plugs, but not the developmental angiogenesis of retina. Bone marrow transplantation revealed that the pro-angiogenic effect depended on CASP11 derived from non-haematopoietic cells. CASP4 expression was induced by inflammatory factors and CASP4 knockdown decreased cell viability, proliferation, migration and tube formation in HUVECs. Mechanistically, CASP4/11 deficiency increased Notch1 activation in vivo and in vitro, while CASP4 overexpression repressed Notch1 signalling in HUVECs. Moreover, CASP4 knockdown increased γ-secretase activity. The γ-Secretase inhibitor DAPT restored the effects of CASP4 siRNA on Notch1 activation and angiogenesis in HUVECs. Notably, the catalytic activity of CASP4/11 was dispensable. CASP4 directly interacted with presenilin-1 through the caspase recruitment domain (CARD). CONCLUSIONS AND IMPLICATIONS: These findings reveal a critical role of CASP4/11 in adult angiogenesis and make this molecule a promising therapeutic target for angiogenesis-related diseases in the future.

Reduced Notch1 Cleavage Promotes the Development of Pulmonary Hypertension.

Clinical trials of Dll4 (Delta-like 4) neutralizing antibodies (Dll4nAbs) in cancer patients are ongoing. Surprisingly, pulmonary hypertension (PH) occurs in 14% to 18% of patients treated with Dll4nAbs, but the mechanisms have not been studied. Here, PH progression was measured in mice treated with Dll4nAbs. We detected Notch signaling in lung tissues and analyzed pulmonary vascular permeability and inflammation. Notch target gene array was performed on adult human pulmonary microvascular endothelial cells (ECs) after inhibiting Notch cleavage. Similar mechanisms were studied in PH mouse models and pulmonary arterial hypertension patients. The rescue effects of constitutively activated Notch1 in vivo were also measured. We observed that Dll4nAbs induced PH in mice as indicated by significantly increased right ventricular systolic pressure, as well as pulmonary vascular and right ventricular remodeling. Mechanistically, Dll4nAbs inhibited Notch1 cleavage and subsequently impaired lung endothelial barrier function and increased immune cell infiltration in vessel walls. In vitro, Notch targeted genes' expression related to cell growth and inflammation was decreased in human pulmonary microvascular ECs after the Notch1 inactivation. In lungs of PH mouse models and pulmonary arterial hypertension patients, Notch1 cleavage was inhibited. Consistently, EC cell-cell junction was leaky, and immune cell infiltration increased in PH mouse models. Overexpression activated Notch1-attenuated progression of PH in mice. In conclusion, Dll4nAbs led to PH development in mice by impaired EC barrier function and increased immune cell infiltration through inhibition of Notch1 cleavage in lung ECs. Reduced Notch1 cleavage in lung ECs could be an underlying mechanism of PH pathogenesis.

A novel peptide inhibitor of Dll4-Notch1 signalling and its pro-angiogenic functions.

BACKGROUND AND PURPOSE: The Dll4-Notch1 signalling pathway plays an important role in sprouting angiogenesis, vascular remodelling and arterial or venous specificity. Genetic or pharmacological inhibition of Dll4-Notch1 signalling leads to excessive sprouting angiogenesis. However, transcriptional inhibitors of Dll4-Notch1 signalling have not been described. EXPERIMENTAL APPROACH: We designed a new peptide targeting Notch signalling, referred to as TAT-ANK, and assessed its effects on angiogenesis. In vitro, tube formation and fibrin gel bead assay were carried out, using human umbilical vein endothelial cells (HUVECs). In vivo, Matrigel plug angiogenesis assay, a developmental retinal model and tumour models in mice were used. The mechanisms underlying TAT-ANK activity were investigated by immunochemistry, western blotting, immunoprecipitation, RT-qPCR and luciferase reporter assays. KEY RESULTS: The amino acid residues 179-191 in the G-protein-coupled receptor-kinase-interacting protein-1 (GIT1-ankyrin domain) are crucial for GIT1 binding to the Notch transcription repressor, RBP-J. We designed the peptide TAT-ANK, based on residues 179-191 in GIT1. TAT-ANK significantly inhibited Dll4 expression and Notch 1 activation in HUVECs by competing with activated Notch1 to bind to RBP-J. The analyses of biological functions showed that TAT-ANK promoted angiogenesis in vitro and in vivo by inhibiting Dll4-Notch1 signalling. CONCLUSIONS AND IMPLICATIONS: We synthesized and investigated the biological actions of TAT-ANK peptide, a new inhibitor of Notch signalling. This peptide will be of significant interest to research on Dll4-Notch1 signalling and to clinicians carrying out clinical trials using Notch signalling inhibitors. Furthermore, our findings will have important conceptual and therapeutic implications for angiogenesis-related diseases.

Nanoparticles based on polymers modified with pH-sensitive molecular switch and low molecular weight heparin carrying Celastrol and ferrocene for breast cancer treatment.

Triple negative breast cancer (TNBC) metastasis is still one of the obstacles in clinical treatment, while highly-effective cancer drugs usually cannot be used for their hydrophobicity and comprehensive system toxicity. This study built a kind of pH-sensitive nanoparticles (PP/H NPs) constructed by poly (lactic-co-glycolic acid) modified with ß-cyclodextrin (PLGA-ß-CD), polyethyleneimine grafted with benzimidazole (PEI-BM) and low molecular weight heparin (LMWH) to delivery Celastrol (Cela) and ferrocene (Fc) for breast cancer therapy. PLGA-ß-CD and PEI-BM were synthesized by amidation reaction, the amphipathic polymer nanoparticles with 108.37 ± 1.02 nm were self-assembled in water. After PP/H NPs treatment, the half maximal inhibitory concentration (IC50) decreased by 91% compared with Cela, and ROS level was also elevated. PP/H NPs led to substantial tumor inhibiting rate (TIR, 65.86%), utilized LMWH to strengthen the anti-metastasis effect of PP/H NPs. PP/H NPs took advantage of exogenous chemotherapeutics and endogenous ROS to inhibit tumor growth, and combined with LMWH to hinder breast cancer metastasis.

Ellagic acid protects dopamine neurons from rotenone-induced neurotoxicity via activation of Nrf2 signalling.

Parkinson's disease (PD) is the second most prevalent central nervous system (CNS) degenerative disease. Oxidative stress is one of key contributors to PD. Nuclear factor erythroid-2-related factor 2 (Nrf2) is considered to be a master regulator of many genes involved in anti-oxidant stress to attenuate cell death. Therefore, activation of Nrf2 signalling provides an effective avenue to treat PD. Ellagic acid (EA), a natural polyphenolic contained in fruits and nuts, possesses amounts of pharmacological activities, such as anti-oxidant stress and anti-inflammation. Recent studies have confirmed EA could be used as a neuroprotective agent in neurodegenerative diseases. Here, mice subcutaneous injection of rotenone (ROT)-induced DA neuronal damage was performed to investigate EA-mediated neuroprotection. In addition, adult Nrf2 knockout mice and different cell cultures including MN9D-enciched, MN9D-BV-2 and MN9D-C6 cell co-cultures were applied to explore the underlying mechanisms. Results demonstrated EA conferred neuroprotection against ROT-induced DA neurotoxicity. Activation of Nrf2 signalling was involved in EA-mediated DA neuroprotection, as evidenced by the following observations. First, EA activated Nrf2 signalling in ROT-induced DA neuronal damage. Second, EA generated neuroprotection with the presence of astroglia and silence of Nrf2 in astroglia abolished EA-mediated neuroprotection. Third, EA failed to produce DA neuroprotection in Nrf2 knockout mice. In conclusion, this study identified EA protected against DA neuronal loss via an Nrf2-dependent manner.

miR-155 inhibits oxidized low-density lipoprotein-induced apoptosis in different cell models by targeting the p85α/AKT pathway.

The apoptosis of vascular endothelial cells (VECs), vascular smooth muscle cells (VSMCs), and macrophages directly causes the instability or rupture of atherosclerotic plaques. Accumulating evidence suggests that oxidized low-density lipoprotein (OxLDL) could induce apoptosis via endogenous or exogenous pathways. Interestingly, it has been reported that microRNA155 (miR-155) plays a pivotal role in the regulation of apoptosis. Here, we hypothesized that overexpression of miR-155 could inhibit OxLDL-induced apoptosis by targeting the p85α/AKT pathway. In this study, we established models of OxLDL-induced apoptosis in mouse VECs, VSMCs, and macrophages. Furthermore, we explored the effects of miR-155 expression on the apoptosis of different cells, and ultimately revealed whether miR-155 regulated apoptosis by targeting the p85α/AKT pathway. The results demonstrated that miR-155 inhibited p85α expression and attenuated VEC, VSMC, and macrophage apoptosis, at least in part by suppressing the expression of p85α-activated AKT to inhibit apoptosis. Our findings collectively suggested that miR-155 attenuated OxLDL-mediated apoptosis in different cells by targeting p85α, supporting its possible therapeutic role in atherosclerosis.

Inflammation-Related MicroRNAs Are Associated with Plaque Stability Calculated by IVUS in Coronary Heart Disease Patients.

OBJECTIVES: This study aimed to investigate the association between inflammation-related microRNAs (miR-21, 146a, 155) and the plaque stability in coronary artery disease patients. METHODS: The expression of miR-21, 146a, and 155 was measured by real-time PCR in 310 consecutive patients. The level of hs-CRP, IL-6, and IL-8 was measured by ELISA. The plaque stability of coronary stenotic lesions was evaluated with intravascular ultrasound (IVUS). RESULTS: (1) The levels of hs-CRP, IL-6, and IL-8 were significantly increased in the UAP and AMI groups compared with the CPS group (P < 0.01). (2) The expression of miR-21 and miR-146a in peripheral blood mononuclear cells (PBMCs) and plasma was significantly higher in CAD patients compared with non-CAD patients, whereas the miR-155 expression in PBMCs and plasma was significantly lower in patients with CAD. (3) The miR-21 expression in PBMCs was higher in UAP and AMI groups compared with CPS group. The miR-146a expression in PBMCs was higher in SAP, UAP, and AMI groups than in CPS group. Although the level of miR-155 in PBMCs was lower in SAP, UAP, and AMI groups than in CPS group. The expression patterns of miR-21, miR-146a, and miR-155 in plasma were consistent with those of PBMCs. (4) The expressions of miR-21 and miR-146a in PBMCs and plasma were significantly higher in the vulnerable plaque group than those in stable plaque group. While miR-155 in PBMCs and plasma was significantly lower in vulnerable plaque group compared with stable plaque group. (5) The levels of miR-21 and miR-146a in PBMCs and plasma were significantly higher in soft plaque group than in fibrous plaque group and calcified plaque group. However, miR-155 in PBMCs and plasma was significantly lower in soft plaque group. CONCLUSIONS: The expression of miR-21 and miR-146a are associated with the plaque stability in coronary stenotic lesions, whereas miR-155 expression is inversely associated with the plaque stability.

Preliminary safety assessment of oridonin in zebrafish.

Context: Oridonin, isolated from the leaves of Isodon rubescens (Hemsl.) H.Hara (Lamiaceae), has good antitumor activity. However, its safety in vivo is still unclear. Objective: To investigate the preliminary safety of oridonin in zebrafish. Materials and methods: Embryo, larvae and adult zebrafish (n = 40) were used. Low, medium and high oridonin concentrations (100, 200 and 400 mg/L for embryo; 150, 300 and 600 mg/L for larvae; 200, 400 and 800 mg/L for adult zebrafish) and blank samples were administered. At specific stages of zebrafish development, spontaneous movement, heartbeat, hatching rate, etc., were recorded to assess the developmental effects of oridonin. VEGFA, VEGFR2 and VEGFR3 gene expression were also examined. Results: Low-dose oridonin increased spontaneous movement and hatching rate with median effective doses (ED50) of 115.17 mg/L at 24 h post-fertilization (hpf) and 188.59 mg/L at 54 hpf, but these values decreased at high doses with half maximal inhibitory concentrations (IC50) of 209.11 and 607.84 mg/L. Oridonin decreased heartbeat with IC50 of 285.76 mg/L at 48 hpf, and induced malformation at 120 hpf with half maximal effective concentration (EC50) of 411.94 mg/L. Oridonin also decreased body length with IC50 of 324.78 mg/L at 144 hpf, and increased swimming speed with ED50 of 190.98 mg/L at 120 hpf. The effects of oridonin on zebrafish embryo development may be attributed to the downregulation of VEGFR3 gene expression. Discussions and conclusions: Oridonin showed adverse effects at early stages of zebrafish development. We will perform additional studies on mechanism of oridonin based on VEGFR3.

Dll4-Notch1 signaling but not VEGF-A is essential for hyperoxia induced vessel regression in retina.

It is well recognized that decreased vascular endothelial growth factor A (VEGF-A) mRNA plays an important role in retinal vessel regression induced by hyperoxia. However, this concept has been challenged by increasing new evidence. Furthermore, VEGF-A strongly enhances Dll4 expression and inhibition of Dll4-Notch signaling leads to excessive sprouting angiogenesis. Recently, it is shown that inactivation of Dll4-Notch1 signaling reduce hyperoxia induced vessel regression. It is unknown whether sprouting angiogenesis contributes to the protective effect or not and further investigations are needed. Moreover, the expression of Dll4 or Notch1 activation in the regressing plexus remains elucidated. To determine the role of VEGF-A and Dll4-Notch1 signaling in hyperoxia induced vascular regression in the retina, we used mice at postnatal day 5 (P5) - P7. Hyperoxia induced massive vascular regression in the central plexus but not in the angiogenic plexus and had no effect on sprouting angiogenesis. Immunostaining showed that VEGF-A was significantly repressed in the angiogenic front region after hyperoxia exposure but not detectable in the central area of both normoxia and hyperoxia treated retinas. In contrast, Notch ligand Delta-like 4 (Dll4) and Notch1 intracellular domain (N1-ICD) expression were inhibited in the regressing capillaries of central retina but comparable in the angiogenic plexus after high oxygen treatment. Moreover, administration of Dll4 neutralizing antibody or γ-Secretase inhibitor DAPT significantly aggravated vessel regression induced by short-time hyperoxia administration. Our data show that repressed Dll4-Notch1 signaling pathway but not downregulation of VEGF-A expression are responsible for hyperoxia induced pervasive vessel regression.

Chelerythrine Inhibits Human Hepatocellular Carcinoma Metastasis in Vitro.

Chelerythrine (CHE) is a type of benzophenanthridine alkaloid found in many herbs and is also the main alkaloid constituent of Toddalia asiatica (L.) LAM. It has been proven to have various activities including antitumor, antifungal, anti-inflammatory and anti-parasitic effects. We have previously demonstrated that CHE can inhibit proliferation and promote apoptosis in human hepatocellular carcinoma (HCC) cells. However, the effect of CHE on the metastasis of HCC and its related molecular mechanisms have yet to be validated. In this study, we investigated the effects of CHE on the migration and invasion of the HCC cell line Hep3B. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), wounding healing, transwell migration and invasion assays and cytoskeleton staining demonstrated that CHE could inhibit the migration and invasion of Hep3B cells in a dose-dependent manner with change of cell structure. RNA interference studies made a knockdown of matrix metalloproteinase (MMP)-2/9 respectively in Hep3B cells. And the results of wounding healing and transwell invasion assay with the treatment of small interfering RNA (siRNA) investigated that MMP-2/9 are positively associated with Hep3B cell metastasis. The results of enzyme-linked immunosorbent assay (ELISA), Western blotting and quantitative RT-PCR showed that CHE suppressed the expression of MMP-2/9 at both mRNA and protein levels. CHE also exhibited an inhibitory effect on the phosphorylation of Focal adhesion kinase (FAK), phosphatidylinositol 3-kinase (PI3K), Akt, mammalian target of rapamycin (mTOR), c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinases (ERK) and p38. In summary, on Hep3B cells, CHE could change the cell cytoskeletal structures through reducing the expression of p-FAK and inhibit the metastasis of Hep3B cells by downregulating the expression of MMP-2/9 mainly through PI3K/Akt/mTOR signaling pathway.

Phospholipase Cγ1 Mediates Intima Formation Through Akt-Notch1 Signaling Independent of the Phospholipase Activity.

BACKGROUND: Vascular smooth muscle cell proliferation, migration, and dedifferentiation are critical for vascular diseases. Recently, it was demonstrated that Notch receptors have opposing effects on intima formation after vessel injury. Therefore, it is important to investigate the specific regulatory pathways that activate the different Notch receptors. METHODS AND RESULTS: There was a time- and dose-dependent activation of Notch1 by angiotensin II and platelet-derived growth factor in vascular smooth muscle cells. When phospholipase Cγ1 (PLCγ1) expression was reduced by small interfering RNA, Notch1 activation and Hey2 expression (Notch target gene) induced by angiotensin II or platelet-derived growth factor were remarkably inhibited, while Notch2 degradation was not affected. Mechanistically, we observed an association of PLCγ1 and Akt, which increased after angiotensin II or platelet-derived growth factor stimulation. PLCγ1 knockdown significantly inhibited Akt activation. Importantly, PLCγ1 phospholipase site mutation (no phospholipase activity) did not affect Akt activation. Furthermore, PLCγ1 depletion inhibited platelet-derived growth factor-induced vascular smooth muscle cell proliferation, migration, and dedifferentiation, while it increased apoptosis. In vivo, PLCγ1 and control small interfering RNA were delivered periadventitially in pluronic gel and complete carotid artery ligation was performed. Morphometric analysis 21 days after ligation demonstrated that PLCγ1 small interfering RNA robustly attenuated intima area and intima/media ratio compared with the control group. CONCLUSIONS: PLCγ1-Akt-mediated Notch1 signaling is crucial for intima formation. This effect is attributable to PLCγ1-Akt interaction but not PLCγ1 phospholipase activity. Specific inhibition of the PLCγ1 and Akt interaction will be a promising therapeutic strategy for preventing vascular remodeling.

Translocase of Inner Membrane 50 Functions as a Novel Protective Regulator of Pathological Cardiac Hypertrophy.

BACKGROUND: Translocase of inner membrane 50 (TIM50) is a member of the translocase of inner membrane (TIM) complex in the mitochondria. Previous research has demonstrated the role of TIM50 in the regulation of oxidative stress and cardiac morphology. However, the role of TIM50 in pathological cardiac hypertrophy remains unknown. METHODS AND RESULTS: In the present study we found that the expression of TIM50 was downregulated in hypertrophic hearts. Using genetic loss-of-function animal models, we demonstrated that TIM50 deficiency increased heart and cardiomyocyte size with more severe cardiac fibrosis compared with wild-type littermates. Moreover, we generated cardiomyocyte-specific TIM50 transgenic mice in which the hypertrophic and fibrotic phenotypes were all alleviated. Next, we tested reactive oxygen species generation and the activities of the antioxidant enzymes superoxide dismutase and catalase, and also respiratory chain complexes I, II, and IV, finding that all the activities were regulated by TIM50. Meanwhile, expression of the ASK1-JNK/P38 axis was increased in TIM50-deficient mice, and TIM50 overexpression decreased the activity of the ASK1-JNK/P38 axis. Finally, we treated mice with the antioxidant N-acetyl cysteine to reduce oxidative stress. After N-acetyl cysteine treatment, the deteriorative hypertrophic and fibrotic phenotypes caused by TIM50 deficiency were all remarkably reversed. CONCLUSIONS: These data indicated that TIM50 could attenuate pathological cardiac hypertrophy primarily by reducing oxidative stress. TIM50 could be a promising target for the prevention and therapy of cardiac hypertrophy and heart failure.

Antiangiogenic effects of oridonin.

BACKGROUND: Oridonin, the major terpene found in Rabdosia rubescens (Henmsl.) Hara, is widely used as a dietary supplement and therapeutic drug. Oridonin has been proven to possess good anti-tumour activity, but little is known about its effect on angiogenesis. The aim of this study was to investigate the antiangiogenic effects of oridonin in vivo and in vitro and prove that oridonin anti-tumour activity is based on suppressing angiogenesis. METHODS: In vitro, the antiangiogenesis effect was studied by proliferation, apoptosis, migration, invasion, and tube formation experiments on human umbilical vascular endothelial cells (HUVECs). In vivo, using the Tg (fli1: GFP) zebrafish model, the embryonic vasculogenesis and postnatal regeneration were evaluated. The vascular endothelial growth factor (VEGF) signalling pathway gene expressions were assessed by reverse transcription-polymerase chain reaction (RT-PCR). Furthermore, the inhibition effects on tumour growth and metastasis were observed using a xenograft zebrafish tumour model and xenograft nude mouse tumour model. Angiogenesis was assayed by immunostaining with cluster of differentiation 31. Importantly, the proteins were identified as being differentially expressed in an in vivo model by two-dimensional electrophoresis-mass spectrometry (2D-MS) and western blot (WB). RESULTS: The results indicated that oridonin inhibited HUVEC proliferation, migration, invasion, and tube formation and induced cell apoptosis. Oridonin inhibited zebrafish angiogenesis during embryonic development and tail fin regeneration. RT-PCR showed that oridonin decreased the VEGFA, VEGFR2, and VEGFR3 expressions in zebrafish, while the TP53 expression increased. Moreover, oridonin had strong effects on tumour growth and metastasis in vivo. 2D-MS identified a total of 50 proteins differentially expressed (17 up-expressed, 28 down-expressed). Lastly, WB showed that Claudin 1, Claudin 4, and Claudin 7 were closely related to tumour growth and metastasis. CONCLUSION: This study demonstrated that oridonin could inhibit tumour growth and metastasis, which mainly based on oridonin antiangiogenic effects. Claudin 1, Claudin 4, and Claudin 7 were the main contributors to the mechanism.

Vaspin attenuates the progression of atherosclerosis by inhibiting ER stress-induced macrophage apoptosis in apoE­/­ mice.

Visceral adipose tissue-derived serine protease inhibitor (vaspin) is a novel adipokine with potential insulin-sensitizing properties, which was initially detected in the visceral adipose tissue of genetically obese rats. Previous studies have demonstrated that vaspin exerts a protective effect on arteries undergoing atherosclerosis in vitro, and it has been shown to exert anti-inflammatory and antimigratory effects on vascular smooth muscle cells. Vaspin promotes proliferation and inhibits apoptosis in endothelial cells, and decreases proliferation of the arterial intima under diabetic conditions. In addition, macrophage apoptosis is an important characteristic of atherosclerotic plaque development. In vivo experiments were performed by histological analysis, including Oil Red O, hematoxylin and eosin and Masson's trichrome staining. Mice were injected with lentivirus via the tail vein and tissues were obtained for histological analysis. Cell apoptosis was determined by flow cytometry of Annexin-V/propidium iodide dual staining and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling assay. Total proteins were extracted and protein expression levels were detected by western blot analysis. The present study aimed to investigate whether vaspin was able to protect against atherosclerotic development in vivo, and to explore the underlying mechanisms of the potential antiatherogenic effects. The results of the current study indicated that vaspin inhibited the progression of atherosclerotic plaques in apoE(­/­) mice by inhibiting endoplasmic reticulum stress-induced macrophage apoptosis.

MicroRNA-155 Promotes Atherosclerosis Inflammation via Targeting SOCS1.

AIMS: Accumulating evidence suggests that atherosclerotic progression depends on persistent and chronic inflammation in the arterial walls. MicroRNA-155 is reportedly involved in cardiovascular disease and has been implicated as a pro-inflammation regulator. Although some researchers have focused on microRNA-155 as an atherosclerosis regulator, the mechanisms by which microRNA-155 functions as a putative pro-atherosclerosis microRNA are largely unknown. This study aims to analyze microRNA-155's effects on atherosclerotic inflammation and to explore its mechanism. METHODS: MicroRNA-155's effects on atherosclerotic inflammation were observed along with the expression and activity levels of SOCS1, STAT3 and NF-κB though microRNA-155 inhibition or overexpression. RESULTS: Highly expressions of microRNA-155 in oxLDL-stimulated macrophages and atherosclerosis mice were inversely correlated with SOCS1 expression. Ectopic microRNA-155 overexpression significantly promoted inflammatory cytokine and chemokine production and atherosclerosis progression. We then observed microRNA-155's functional role in the atherosclerotic pathophysiological process in vivo and in vitro. The observation revealed that by enhancing STAT3 and NF-κB signaling and facilitating immune inflammation by targeting SOCS1, microRNA-155 plays a promotable role in atherosclerosis progression. CONCLUSIONS: microRNA-155 works as a promoter in the atherosclerotic procession. Its mechanism may include enhancing inflammatory response in atherosclerosis by increasing STAT3 and NF-κB signaling via targeting SOCS1.

In Vitro and In Vivo Antitumor Effects of n-Butanol Extracts of Pterocephalus hookeri on Hep3B Cancer Cell.

Pterocephalus hookeri is a widely applied Tibetan medicinal prescription for treatment of diseases such as flu, rheumatoid arthritis, and enteritis in China. It has been reported that Pterocephalus hookeri has anti-inflammatory and analgesic actions. However, the antitumor activity of Pterocephalus hookeri remains unknown. In the present study, we demonstrate that n-butanol extracts of Pterocephalus hookeri (YSC-ZDC) has a strong antitumor activity against hepatoma carcinoma cell in vitro and in vivo. YSC-ZDC inhibited proliferation of all cancer cell lines and significantly inhibited Hep3B cells proliferation in a dose- and time-dependant manner. Transmission electron microscopy, hoechst 33258 staining, and flow cytometry analysis revealed that YSC-ZDC induced apoptosis in Hep3B cells. YSC-ZDC treatment dramatically inhibited PDK1 and Akt phosphorylation in Hep3B cells. Moreover, YSC-ZDC increased Bax expression and inhibited Bcl-2 expression. In addition, YSC-ZDC inhibited growth hepatoma xenografts in vivo with no effect on body weight and spleen index. Consistent with results in vitro, YSC-ZDC increased Bax expression and inhibited Bcl-2 expression in tumor tissue. Taken together, this study shows YSC-ZDC with an antitumor activity both in vitro and in vivo. Its mechanism underlying is related to blocking of the Akt pathway and regulation of Bcl-2 family proteins expression.

microRNA-155 is inversely associated with severity of coronary stenotic lesions calculated by the Gensini score.

OBJECTIVES: This study aimed to investigate the association between microRNA-155 (miR-155) and the severity and extent of coronary stenotic lesions. PATIENTS AND METHODS: We measured the miR-155 expression by real-time PCR in 110 consecutive patients undergoing coronary angiography for suspected coronary artery disease. The severity and extent of coronary stenotic lesions were evaluated on the basis of coronary angiography findings by the Gensini score. RESULTS: The miR-155 expression was significantly lower in 56 patients with coronary heart disease than those in 54 controls (P<0.01). The level of miR-155 in peripheral blood mononuclear cells or plasma was lower in patients with unstable angina pectoris and acute myocardial infarction than in patients with chest pain syndrome, whereas no statistically significant differences were observed between patients with stable angina pectoris and chest pain syndrome. Spearman's correlation analysis showed that the expression of miR-155 in plasma correlated positively with the expression in peripheral blood mononuclear cells. The levels of miR-155 in the patients with diseased vessels of two and three or more were significantly lower than in those with diseased vessel of zero and one. The levels of miR-155 were not significantly different among groups with diseased vessels of zero and one. miR-155 were associated negatively with Gensini scores (r = -0.663, P<0.001). The miR-155 expression was correlated significantly to age (r = -0.227), hypertension (r = -0.440), total cholesterol (r = 0.239), high-density lipoprotein cholesterol (r = 0.280), low-density lipoprotein cholesterol (r = -0.315), tobacco use (r = -0.363), angiotensin-converting enzyme inhibitor (r = -0.250), statins (r = -0.368), and high-sensitivity C-reactive protein (r = -0.515). CONCLUSION: miR-155 expression is associated inversely with complicated proatherogenic metabolic risk factors, and the severity of coronary stenotic lesions calculated by Gensini scores.

miR-155 inhibits oxidized low-density lipoprotein-induced apoptosis of RAW264.7 cells.

Macrophage apoptosis is a prominent feature of advanced atherosclerotic plaques. Here, we examined the hypothesis that the apoptotic machinery is regulated by microRNA-155 (miR-155). Constitutive expression of miR-155 was detected in RAW264.7 cells, which was increased following stimulation with oxidized low-density lipoprotein (OxLDL) in a dose- and time-dependent manner. OxLDL-treated RAW264.7 cells showed a marked time- and dose-dependent increase in apoptosis, which was suppressed in the presence of mimics and increased with antagonists of miR-155. Bioinformatics analysis revealed Fas-associated death domain-containing protein (FADD) as a putative target of miR-155. Luciferase reporter assay and Western blot further disclosed that miR-155 inhibits FADD expression by directly targeting the 3'-UTR region. We propose that miR-155 attenuates the macrophage apoptosis, at least in part, through FADD regulation, since forced expression of FADD blocked the ability of miR-155 to inhibit apoptosis. Our results collectively suggest that miR-155 attenuates apoptosis of OxLDL-mediated RAW264.7 cells by targeting FADD, supporting a possible therapeutic role in atherosclerosis.

New isoprenylated flavonoids and cytotoxic constituents from Artocarpus tonkinensis.

Two new isoprenylated flavonoids, artotonins A and B (1 and 2), along with 13 known compounds (3-15), were isolated from the roots of Artocarpus tonkinensis A. Chev. ex Gagnep. The structures were elucidated by spectroscopic methods. Cyclocommunol (6), isocyclomulberrin (7), cudraflavone C (11), and morusin (13) exhibited cytotoxicity against hepatocellular carcinoma (SMMC-7721) and gastric carcinoma (BGC-823 and SGC-7901) cell lines.