AHR is a tunable knob that controls HTLV-1 latency-reactivation switching.

Establishing latent infection but retaining the capability to reactivate in certain circumstance is an ingenious tactic for retroviruses to persist in vivo while evading host immune surveillance. Many evidences indicate that Human T-cell leukemia virus type 1 (HTLV-1) is not completely silent in vivo. However, signals that trigger HTLV-1 latency-reactivation switching remain poorly understood. Here, we show that aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, plays a critical role in HTLV-1 plus-strand expression. Importantly, HTLV-1 reactivation could be tunably manipulated by modulating the level of AHR ligands. Mechanistically, activated AHR binds to HTLV-1 LTR dioxin response element (DRE) site (CACGCATAT) and drives plus-strand transcription. On the other hand, persistent activation of nuclear factor kappa B (NF-κB) pathway constitutes one key prerequisite for AHR overexpression in HTLV-1 infected T-cells, setting the stage for the advent of AHR signaling. Our findings suggest that HTLV-1 might achieve its reactivation in vivo when encountering environmental, dietary, microbial and metabolic cues that induce sufficient AHR signaling.

Anti-HBV Activities of Polysaccharides from Thais clavigera (Küster) by In Vitro and In Vivo Study.

Hepatitis B virus (HBV) infection remains a major global health problem. It is therefore imperative to develop drugs for anti-hepatitis B with high-efficiency and low toxicity. Attracted by the observations and evidence that the symptoms of some patients from the Southern Fujian, China, suffering from hepatitis B were alleviated after daily eating an edible marine mollusk, Thais clavigera (Küster 1860) (TCK). Water-soluble polysaccharide from TCK (TCKP1) was isolated and characterized. The anti-HBV activity of TCKP1 and its regulatory pathway were investigated on both HepG2.2.15 cell line and HBV transgenic mice. The data obtained from in vitro studies showed that TCKP1 significantly enhanced the production of IFN-α, and reduced the level of HBV antigens and HBV DNA in the supernatants of HepG2.2.15 cells in a dose-dependent manner with low cytotoxicity. The result of the study on the HBV transgenic mice further revealed that TCKP1 significantly decreased the level of transaminases, HBsAg, HBeAg, and HBV DNA in the serum, as well as HBsAg, HBeAg, HBV DNA, and HBV RNA in the liver of HBV transgenic (HBV-Tg) mice. Furthermore, TCKP1 exhibited equivalent inhibitory effect with the positive control tenofovir alafenamide (TAF) on the markers above except for HBV DNA even in low dosage in a mouse model. However, the TCKP1 high-dose group displayed stronger inhibition of transaminases and liver HBsAg, HBeAg, and HBV RNA when compared with those of TAF. Meanwhile, inflammation of the liver was, by pathological observation, relieved in a dose-dependent manner after being treated with TCKP1. In addition, elevated levels of interleukin-12 (IL-12) and interferon γ (IFN-γ), and reduced level of interleukin-4 (IL-4) in the serum were observed, indicating that the anti-HBV effect of TCKP1 was achieved by potentiating immunocyte function and regulating the balance of Th1/Th2 cytokines.

Novel Ferrocene Derivatives Induce G0/G1 Cell Cycle Arrest and Apoptosis through the Mitochondrial Pathway in Human Hepatocellular Carcinoma.

In this study, detailed information on hepatocellular carcinoma (HCC) cells (HepG-2, SMMC-7721, and HuH-7) and normal human liver cell L02 treated by ferrocene derivatives (compounds 1, 2 and 3) is provided. The cell viability assay showed that compound 1 presented the most potent and selective anti-HCC activity. Further mechanism study indicated that the proliferation inhibition effect of compound 1 was associated with the cycle arrest at the G0/G1 phase and downregulation of cyclin D1/CDK4. Moreover, compound 1 could induce apoptosis in HCC cells by loss of mitochondrial membrane potential (ΔΨm), accumulation of reactive oxygen species (ROS), decrease in Bcl-2, increase in BAX and Bad, translocation of Cytochrome c, activation of Caspase-9, -3, and cleavage of PARP. These results indicated that compound 1 would be a promising candidate against HCC through G0/G1 cell cycle arrest-related proliferation inhibition and mitochondrial pathway-dependent apoptosis.

Antioxidant, Hypolipidemic and Hepatic Protective Activities of Polysaccharides from Phascolosoma esculenta.

The aims of this study were to investigate the antioxidant, hypolipidemic and hepatic protective effects of Phascolosoma esculenta polysaccharides (PEP). PEP was prepared from Phascolosoma esculenta by enzyme hydrolysis and its characterization was analyzed. The antioxidant activities of PEP were evaluated by the assays of scavenging 1,1-Diphenyl-2-picrylhydrazyl (DPPH), superoxide anion, hydroxyl radicals and chelating ferrous ion in vitro. It showed that PEP could scavenge radicals effectively and had favorable antioxidant activities. In the meantime, the hypolipidemic effect of PEP was investigated in vivo by using mice model fed with high-fat diet with or without PEP treatment. Compared with the hyperlipidemic mice without treatment, the serum levels of total cholesterol (TC) (30.1-35.7%, p < 0.01), triglyceride (TG) (24.5-50.8%, p < 0.01 or p < 0.05), low-density lipoprotein cholesterol (LDL-C) (49.6-56.8%, p < 0.01) and liver levels of TC (21.0-28.4%, p < 0.01), TG (23.8-37.0%, p < 0.01) decreased significantly, whereas serum high-density lipoprotein cholesterol (HDL-C) (47.7-59.9%, p < 0.01 or p < 0.05) increased significantly after treatment with different dosage of PEP (0.2, 0.4 and 0.8 g per kg body weight, respectively). In addition, superoxide dismutase (SOD) (10.2-22.2% and 18.8-26.9%, p < 0.05), glutathione peroxidase (GSH-Px) (11.9-15.4% and 26.6-30.4%, p < 0.05) activities in serum and liver enhanced markedly while aspartate aminotransferase (AST) (18.7-29.6% and 42.4-58.0%, p < 0.05), alanine transaminase (ALT) (42.7-46.0% and 31.2-42.2%, p < 0.05) activities, as well as the levels of malondialdehyde (MDA) (15.9-24.4% and 15.0-16.8%, p < 0.01 or p < 0.05) in serum and liver reduced markedly. Moreover, the histopathological observation of livers indicated that PEP could attenuate liver cell injury. The animal experimental results demonstrated that PEP exerted hypolipidemic and hepatoprotective roles in hyperlipidemic mice. In summary, our results above suggest that PEP might be a potential natural antioxidant and utilized as a therapeutic candidate for hyperlipidemia.

Activation of Notch1 signaling by HTLV-1 Tax promotes proliferation of adult T-cell leukemia cells.

Human T-cell leukemia virus 1 (HTLV-1), an oncogenic retrovirus, and Notch1 signaling, implicated in tumor formation and progression, are both associated with the development of adult T-cell leukemia (ATL). Here we explored the possibility of a mechanistic link between the two. We observed that the expression of Notch intracellular domain (NICD) was elevated in HTLV-1 infected cell lines. Knocking down of Notch1 in ATL cells repressed cellular proliferation and tumor formation both in vitro and in vivo. As a mechanism for these actions, we found that Tax activated Notch1 signaling by prolonging the half-life of NICD. We then showed that Tax, NICD, and RBP-jκ formed a ternary complex, that Tax enhanced the association of NICD with RBP-jκ, and that Tax, NICD, and RBP-jκ were bound to RBP-jκ-responsive elements. Hence, our results suggest that HTLV-1 promotes cellular proliferation and tumor formation of ATL cells by modulating Notch signaling via a posttranslational mechanism that involves interactions between Tax, NICD, and RBP-jκ.

Association of N6-methyladenosine with viruses and related diseases.

BACKGROUND: N6-methyladenosine (m6A) modification is the most prevalent internal modification of eukaryotic mRNA modulating gene expression. m6A modification is a dynamic reversible process regulated by three protein groups: methyltransferases (writers), demethylases (erasers), and m6A-binding proteins (readers). m6A modification is involved in all phases of RNA metabolism, including RNA folding, stability, splicing, nuclear exporting, translational modulation and degradation. MAIN BODY: In recent years, numerous studies have reported that abnormal m6A modification causes aberrant expression of important viral genes. Herein, we review the role of m6A in viral lifecycle and its contribution to the pathogenesis of human diseases. Particularly, we focus on the viruses associated with human diseases such as HIV-1, IAV, HBV, HCV, EBV and many others. CONCLUSIONS: A better understanding of m6A-virus relationship would provide new insights into the viral replication process and pathogenesis of human diseases caused by viruses. In addition, exploration of the role of m6A in disease-causing viruses will reveal novel approaches for the treatment of such diseases.

Efficient Extraction of Anti-Inflammatory Active Ingredients from Schefflera octophylla Leaves Using Ionic Liquid-Based Ultrasonic-Assisted Extraction Coupled with HPLC.

Schefflera octophylla (Lour.) Harms, a kind of traditional Chinese medicine (TCM), is commonly used for anti-inflammatory, analgesic, rheumatism, fever, and hemostasis therapy. In our previous studies, two major triterpenoids were isolated and identified from leaves of S. octophylla, and evaluated for their inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide production in RAW264.7 cells; both of them displayed significant anti-inflammatory activities at their noncytotoxic concentrations. Therefore, it is very useful to establish an efficient and green extraction method to isolated the two major triterpenoids from leaves of S. octophylla. In this paper, ionic liquid based ultrasonic-assisted extraction (ILUAE) was successfully applied to extract the two major triterpenoids from leaves of S. octophylla. Four single factors (ionic liquids (ILs) concentration, solid-liquid ratio, centrifugal speed, mesh number), with a greater impact on extraction rate, were selected from a variety of influencing factors, and the optimal conditions were obtained by Box-Behnken response surface methodology (RSM). Under optimal conditions, the total extraction yield and extraction rate of two triterpenoids were 288.03 mg/g and 28.80%, respectively, which was 6.80% higher than that of 70% Ethanol (220 mg/g and 22%, respectively).

Coagulant Effects and Mechanism of Schefflera heptaphylla (L.) Frodin.

Schefflera heptaphylla (L.) Frodin, are commonly used in anti-inflammatory, analgesic, traumatic bleeding and hemostasisas. In this paper, the coagulation effect of the ethanol extract (Set), ethyl acetate phase (Sea) and n-butanol phase (Sbu) was evaluated by prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen content (FIB) assays in vitro. Then, Three main lupanine triterpenes (compounds A-C) were isolated and identified from Sea and Sbu by a bioassay-guided method and their structure were identified as 3α-Hydroxy-lup-20(29)-ene-23, 28-dioic acid, betulinic acid 3-O-sulfate and 3α-Hydroxy-lup-20(29)-ene-23, 28-dioic acid 28-O-(α-l-rhamnopyranosyl(1→4)-O-ß-d-glucopyranosyl(1→6))-ß-d-glucopyranoside) by spectroscopic data analysis. Among of them, compound B was confirmed to have significant coagulant effect in vitro. Furthermore, the pro-coagulation mechanism of S. heptaphylla extracts and compound B were investigated by measuring whole blood viscosity (WBV), plasma viscosity (PV), erythrocyte sedimentetion rate (ESR), pack cell volume (PCV), APTT, PT, TT, and FIB in vivo. Meanwhile, the levels of thromboxane B2 (TXB2), 6-keto prostaglandin F1α (6-keto-PGF1α), endothelial nitric oxide synthase (eNOS) and (endothelin-1) ET-1 were detected. The bleeding time (BT) was tested by tail bleeding method, which proved the traumatic bleeding and hemostasis activities of S. heptaphylla. The pharmacology experiments showed that the Set, Sea, Sbu and compound B has significant pro-coagulation effect. In addition, compound B might be the main constituent of pro-coagulation in S. heptaphylla These results could support the fact that S. heptaphylla could be used traditionally to cure traumatic bleeding, and the pro-coagulation effects were associated with the regulation of vascular endothelium active substance and hemorheology parameters.

IL-8 Secreted from M2 Macrophages Promoted Prostate Tumorigenesis via STAT3/MALAT1 Pathway.

Prostate cancer (PCa) is a major health problem in males. Metastasis-associated with lung adenocarcinoma transcript-1 (MALAT1), which is overexpressed in PCa tissue, is associated with physiological and pathological conditions of PCa. M2 macrophages are major immune cells abundant in the tumor microenvironment. However, it remains unknown whether M2 macrophages are involved in the effects or not, and molecular mechanisms of MALAT1 on PCa progression have not yet been comprehensively explored. Here we reported that, M2 macrophages (PMA/IL-4 treated THP1) induced MALAT1 expression in PCa cell lines. Knockdown MALAT1 expression level in PCa cell lines inhibited cellular proliferation, invasion, and tumor formation. Further mechanistic dissection revealed that M2 macrophages secreted IL-8 was sufficient to drive up MALAT1 expression level via activating STAT3 signaling pathway. Additional chromatin immunoprecipitation (ChIP) and luciferase reporter assays displayed that STAT3 could bind to the MALAT1 promoter region and transcriptionally stimulate the MALAT1 expression. In summary, our present study identified the IL-8/STAT3/MALAT1 axis as key regulators during prostate tumorigenesis and therefore demonstrated a new mechanism for the MALAT1 transcriptional regulation.

[Research advances on hypolipidemic effect of polysaccharides].

Hyperlipidemia is a systemic chronic metabolic disease caused by dyslipidemia in the body. It is an important risk factor of accelerating atherosclerosis, which will cause coronary heart disease, thrombus and other cardiovascular diseases, so it is a "invisible killer" for human health. Controlling and lowering blood lipids can reduce the risk of cardiovascular and cerebrovascular diseases. The current therapies for hyperlipidemia mainly include chemical synthetic medicines. However, long-term use of hypolipidemic drugs would cause various side effects, and the demand of effective and nontoxic drugs for hyperlipidemia patients is eager. Polysaccharide has attracted worldwide concerns due to its characteristics of good biocompatibility and less side effects. Polysaccharide is a kind of biological macromolecule which is widely found in plant cell walls, animal cell membranes and microorganism cell walls. A number of studies have shown that polysaccharides from natural materials have broad biological activities, such as anti-tumor, immunomodulatory, antioxidant, hypoglycemic, and hypolipidemic effects, with broad application prospect. This paper has reviewed and summarized the polysaccharides with hypolipidemic effect and their mechanisms which have been reported at home and abroad, hoping to provide certain reference for their development and application in lowering blood lipids.

Two novel phenanthraquinones with anti-cancer activity isolated from Bletilla striata.

7-Hydroxy-2-methoxy-phenanthrene-3,4-dione and 3',7',7-trihydroxy-2,2',4'-trimethoxy-[1,8'-biphenanthrene]-3,4-dione, two novel compounds and four known compounds were isolated from Bletilla striata. The structures of the compounds were established on the basis of extensive spectroscopic analysis. The two compounds exhibited antiproliferative effects using the MTT test; these effects may be due to cell cycle arrest and inducing ROS generation.

Biological Evaluation of Ferrocenyl Olefins: Cancer Cell Growth Inhibition, ROS Production, and Apoptosis Activity.

The antiproliferative effects of various ferrocenyl olefins were evaluated against the cell lines MCF-7 (human breast cancer cells), DLD-1 (human colon adenocarcinoma cells), HUVEC (human umbilical vein endothelial cells), and A549 (human lung carcinoma cells), using the MTT test. IC50 values were determined. Compounds 8, 9, 11, and 12 with high antiproliferative activity were tested for their reactive oxygen species (ROS) production, and cell cycle analysis was performed on A549 cells. The results show that these compounds might perform their antiproliferative activity through inducing ROS generation, apoptosis induction, and cell cycle arrest.

[Relationship between hepatitis B virus X protein and hepatic cellular cancer].

Hepatic cellular cancer (HCC) is one of the most common cancers in the world, which is a serious threat to human health and life quality. More than 700,000 people die of HCC each year on average, and its incidence increases in many countries. Chronic hepatitis B virus (HBV) infection has been identified as a dominant risk factor for HCC. The pathogenesis of HBV-induced hepatocarcinogenesis is, however, incompletely understood. Evidence currently available supports a key role of the HBV X protein (HBx) in the cancer transformation and malignant tumor metastasis. HBx is a multifunctional regulator that may cooperate with the host factors to exert its effects on transcription, signal transduction, cell cycle progression, apoptosis, protein degradation, expression of oncogene and anti-oncogene. This review presents the current knowledge in the molecular pathogenesis of HBx in the induction of HCC.

Hypericin-mediated photodynamic therapy induces apoptosis of myoloma SP2/0 cells depended on caspase activity in vitro.

BACKGROUND: Photodynamic therapy (PDT) is becoming a promising therapeutic modality for hematological malignancies. Hypericin is a natural photosensitizer possessing anti-depressant, anti-virus and anti-cancer activities. The present study was designed to explore the effect and mechanism of hypericin-mediated PDT on the mouse multiple myeloma (MM) cells in vitro. METHODS: The mouse myeloma SP2/0 cells were incubed with different concentrations of hypericin and then illuminated with different light doses. The inhibitory effect of hypericin-mediated PDT on tumor cell proliferation was assayed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) method. The apoptosis related morphological changes of SP2/0 cells were observed by microscopy. The biochemical hallmarks of apoptosis such as DNA fragments, mitochondrial membrane potential changes were assessed. The expression of apoptosis related proteins were investigated by western blotting. RESULTS: Hypericin-mediated PDT induced the proliferation inhibition and apoptosis of tumor cells in a dose dependent manner. Tumor cells showed obvious morphological changes of apoptosis and necrosis and DNA fragmentation after treated by hypericin mediated PDT (0.025 ~ 0.05 µM). The mitochondria membrane potential in SP2/0 cells was decreased significantly after incubated with the 0.025 µM and 0.5 µM hypericin (P < 0.05). The expression level of caspase-3 was decreased, while caspase activity was elevated with the increasing drug dosage. The apoptosis of SP2/0 cells was blocked by a pan-caspase inhibitor Z-VAD-FMK and caspase-3 inhibitor Ac-DEVD-CHO. CONCLUSION: Hypericin-mediated PDT induced apoptosis mainly dependent on caspase related pathways. Hypericin-mediated PDT may be a potential and alternative therapy for MM.

Neuroprotection by saponins.

Saponins, an important group of bioactive plant natural products, are glycosides of triterpenoid or steroidal aglycones. Their diverse biological activities are ascribed to their different structures. Saponins have long been recognized as key ingredients in traditional Chinese medicine. Accumulated evidence suggests that saponins have significant neuroprotective effects on attenuation of central nervous system disorders, such as stroke, Alzheimer's disease, Parkinson's disease, and Huntington's disease. However, our understanding of the mechanisms underlying the observed effects remains incomplete. Based on recently reported data from basic and clinical studies, this review highlights the proposed mechanisms of their neuroprotective function including antioxidant, modulation of neurotransmitters, anti-apoptosis, anti-inflammation, attenuating Ca(2+) influx, modulating neurotrophic factors, inhibiting tau phosphorylation, and regeneration of neural networks.

[Interaction of E3 ligase HUWE1 and eukaryotic translation initiation factor eIF4E].

To explore the regulation of eIF4E, we screened the protein interacting with eIF4E from human cDNA library by using yeast two-hybrid system. Several clones interacting with eIF4E were identified. One of them was homologous with HUWE1 (HECT, UBA and WWE domain containing 1, also named as ARF-BP1, HECTH9 or HUWE1). Cell co-immunoprecipitation showed that eIF4E could bind to HUWE1 in mammalian cells. We also found that HUWE1 bearing the HECT domain is necessary for its association with eIF4E.

[Adeno-associated vector mediated intracellular biological activity of human Kallistatin].

Human tissue kallikrein-binding protein (Kallistatin, KAL), a secretory protein that participates in the regulation of multiple signaling pathways by binding to the extracellular receptor, however, at present has not been reported about the intracellular activity, and whether it has the similar biological activity with extracellular activity. Here we constructed no signal peptide KAL (NSK) into the adeno-associated virus vector to explore the intracellular activity of KAL. Both the endothelial cell and lung cancer cells could express KAL, but not secreted after rAAV2-NSK transfection. The proliferation and migration of human umbilical vein endothelial cells (HUVECs) were inhibited, but the apoptosis rate was not affected. The proliferation rates, mobility and tubule formation of all the three tested lung cancer cells, such as NCI-H446, NCI-H460 and A549, were inhibited to different extents. This cellular study not only confirmed the intracellular activity, but also suggested it may serve as a kind of "balance factor" in multi-targeted controlling, which may provide a new train of thoughts to explain the regulatory contradiction in PI3K-Akt signaling pathways by KAL.

Cytotoxic activity of the alkaloids from Broussonetia papyrifera fruits.

CONTEXT: Broussonetia papyrifera (L.) Vent. (Moraceae), a traditional Chinese medicinal herb, has been extensively applied for many years to treat various diseases. Recently, a number of compounds with biological and pharmacological activities have been extracted from the plant and used as chemotherapeutic candidates to treat a range of diseases such as cancer. OBJECTIVE: The current study was designed to isolate the alkaloid compounds from ethyl acetate extraction of Broussonetia papyrifera fruits, and to evaluate the cytotoxic activity of total alkaloids as well as individual isoquinoline alkaloids from B. papyrifera fruits. METHODS: Alkaloid compounds were isolated from the ethyl acetate extraction by silica gel column chromatography methods using CHCl3/MeOH as eluents. The compounds' structures were determined by detailed analysis of NMR, MS spectral data, and chemical methodology. Cytotoxic activity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) methods against human A375, Hela, BEL-7402 cancer cells, and non-cancer cells. RESULTS: Two isoquinonline alkaloids were isolated and characterized as N-norchelerythrine and dihydrosanguinarine. The total alkaloids and seven individual alkaloids had higher activities on BEL-7402 and Hela cell lines with low IC50 values 6.61-47.41 and 5.97-40.17 µg/mL (<50 µg/mL). Nitidine, broussonpapyrine, and chelerythrine had strong toxic on non-cancer cells with IC50 value 18.01, 19.91, and 22.31 µg/mL, respectively. DISCUSSION: N-Norchelerythrine and dihydrosanguinarine were isolated from this plant for the first time. Our data implicated that seven isoquinoline alkaloids had cytotoxity with structure-activity relationships, which provided fundamental information for further modification of their anticancer effect.

Design and Synthesis of Electrocatalysts Base on Catalysis-Unit Engineering.

It is a pressing need to develop new energy materials to address the existing energy crisis. However, screening optimal targets out of thousands of material candidates remains a great challenge. Herein, an alternative concept for highly effective materials screening based on dual-atom salphen catalysis units, is proposed and validated. Such an approach simplifies the design of catalytic materials and reforms the trial-and-error experimental model into a building-blocks-assembly like process. First, density functional theory (DFT) calculations are performed on a series of potential catalysis units that are possible to synthesize. Then, machine learning (ML) is employed to define the structure-performance relationship and acquire chemical insights. Afterward, the projected catalysis units are integrated into covalent organic frameworks (COFs) to validate the concept Electrochemical tests confirming that Ni-SalphenCOF and Co-SalphenCOF are promising conductive agent-free oxygen evolution reaction (OER) catalysts. This work provides a fast-tracked strategy for the design and development of functional materials, which serves as a potentially workable framework for seamlessly integrating DFT calculations, ML, and experimental approaches.

[Strategy for keeping efficient expression and pharmacodynamics in reducing rAAV gene medicine immune response based on the decrease of vector dosage].

How to reduce immune response is an unprecedented challenge for rAAV gene medicine. Recent studies suggested that lowering dosage of the vector used could reduce immune response caused by rAAV gene medicine. Nevertheless, it would also decrease the transgene expression, leading to failure of gene treatment. It is therefore important to take appropriate steps to maintain high gene expression level and pharmacodynamic, while the dosage of rAAV used is reduced. Here, steps to enhancing gene therapy, such as optimization of the administration, reconstruction of the viral vector and selection of the promoter, are discussed in order to achieve maximum outcome.