Given the high risk and lengthy procedure of traditional drug development, drug repurposing is gaining more and more attention. Although many types of drug information have been used to repurpose drugs, drug–drug interaction data, which imply possible physiological effects or targets of drugs, remain unexploited. In this work, similarity of drug interaction was employed to infer similarity of the physiological effects or targets for the drugs. We collected 10 835 drug–drug interactions concerning 1074 drugs, and for 700 of them, drug similarity scores based on drug interaction profiles were computed and rendered using a drug association network with 589 nodes (drugs) and 2375 edges (drug similarity scores). The 589 drugs were clustered into 98 groups with Markov Clustering Algorithm, most of which were significantly correlated with certain drug functions. This indicates that the network can be used to infer the physiological effects of drugs. Furthermore, we evaluated the ability of this drug association network to predict drug targets. The results show that the method is effective for 317 of 561 drugs that have known targets. Comparison of this method with the structure‐based approach shows that they are complementary. In summary, this study demonstrates the feasibility of drug repurposing based on drug–drug interaction data.
ABSTRACT Tenascin-C is an extracellular matrix glycoprotein, the expression of which is upregulated in remodeling arteries. In previous studies we showed that the presence of tenascin-C alters vascular smooth muscle cell shape and amplifies their proliferative response by promoting growth factor receptor clustering and phosphorylation. Moreover, we demonstrated that denatured type I collagen induces smooth muscle cell tenascin-C protein production via β3 integrins. In the present study, we examine the pathway by which β3 integrins stimulate expression of tenascin-C, and define a promoter sequence that is critical for its induction. On native collagen, A10 smooth muscle cells adopt a stellate morphology and produce low levels of tenascin-C mRNA and protein, whereas on denatured collagen they spread extensively and produce high levels of tenascin-C mRNA and protein, which is incorporated into an elaborate extracellular matrix. Increased tenascin-C synthesis on denatured collagen is associated with elevated protein tyrosine phosphorylation, including activation of extracellular signal-regulated kinases 1 and 2 (ERK1 and ERK2). β3 integrin function-blocking antibodies attenuate ERK1/2 activation and tenascin-C protein synthesis. Consistent with these findings, treatment with the specific MEK inhibitor, PD 98059, results in suppression of tenascin-C protein synthesis. To investigate whether β3 integrin-dependent activation of ERK1/2 regulates the tenascin-C promoter, we transfected A10 cells with a full-length (approx. 4 kb) mouse tenascin-C gene promoter-chloramphenicol acetyltransferse reporter construct and showed that, relative to native collagen, its activity is increased on denatured collagen. Next, to identify regions of the promoter involved, we examined a series of tenascinC promoter constructs with 5′ deletions and showed that denatured collagen-dependent promoter activity was retained by a 122-base pair element, located −43 to −165 bp upstream of the RNA start site. Activation of this element was suppressed either by blocking β3 integrins, or by preventing ERK1/2 activation. These observations demonstrate that smooth muscle cell binding to β3 integrins activates the mitogen activated protein kinase pathway, which is required for the induction of tenascin-C gene expression via a potential extracellular matrix response element in the tenascin-C gene promoter. Our data suggest a mechanism by which remodeling of type I collagen modulates tenascin-C gene expression via a β3 integrin-mediated signaling pathway, and as such represents a paradigm for vascular development and disease whereby smooth muscle cells respond to perturbations in extracellular matrix composition by altering their phenotype and patterns of gene expression.
Aim To study the effect of protein kinase C inhibitor Ro 31-8220 on secretion of fibrinogen.Methods Horseradish peroxidase was conjugated to human fibrinogen and cell supernatant fibrinogen was quantitated with ELISA.Results Macrophage endogenous medium preincubated by LPS stimulates the synthesis and secretion of fibrinogen from Hep 3B cells. Protein kinase C inhibitor Ro 31-8220(10～1 000nmol·L -1 )exerted inhibitory effects.Conclusion Protein kinase C inhibitor Ro 31-8220 inhibits the synthesis of fibrinogen.
The combined effects of matrine (Mat) and cisplatin on the survival and apoptosis of rhabdomyosarcoma (RMS) RD cells, as well as the possible mechanism of the synergistic effect of Mat and cisplatin were investigated in the present study. RMS RD cells were divided and treated as follows: control group, 5 mg/l cisplatin group, Mat groups (0.5, 1.0 and 1.5 g/l), and Mat (0.5, 1.0 and 1.5 g/l) combined with 5 mg/l cisplatin groups. An MTT assay and flow cytometry were applied to detect the survival and apoptotic rates, respectively, while RT-PCR was applied to detect the expression levels of X-linked inhibitor of apoptosis protein (XIAP) mRNA in the RD cells of each group. The survival rates of RD cells in each experimental group were lower than in the control group, and the apoptotic rates were higher than those in the control group (P<0.05). An increase in drug concentrations led to the cell proliferation inhibitory and apoptotic rates of the single Mat groups increasing as a function of dose (pairwise comparison among the groups, P<0.05), while the proliferation inhibitory and apoptotic rates of Mat combined with the cisplatin groups under different concentration were significantly higher than those of the single Mat and single cisplatin groups under the same concentration (P<0.01). The expression levels of XIAP mRNA in the RD cells of each experimental group were lower than those in the control group (P<0.05). Additionally, the expression levels of XIAP mRNA in the group treated with Mat and cisplatin were significantly lower than those of the single cisplatin and single Mat groups (P<0.01). In conclusion, Mat and cisplatin are capable of inhibiting the proliferation of RD cells and inducing apoptosis by suppressing the XIAP mRNA expression levels.
Snakebite incidence in southwestern China is mainly attributed to one of the several venomous snakes found in the country, the white-lipped green pit viper Trimeresurus albolabris. Since antivenom produced from horses may cause numerous clinical side effects, the present study was conducted aiming to develop an alternative antivenom antibody (immunoglobulin Y - IgY) from leghorn chickens.IgY in egg yolk from white leghorn chicken previously injected with T. albolabris venom was extracted by water, precipitated by ammonium sulfate and purified by affinity chromatographic system. IgY was identified by SDS-PAGE, ELISA and Western blot, and its neutralizing assay was conducted on mice.Chickens injected multiple times with T. albolabris venom elicited strong antibody responses, and from their egg yolk IgY was isolated and purified, which exhibited a single protein band on SDS-PAGE and two bands (about 65 and 35 kDa, respectively) under reduced conditions. Immunoblot analysis revealed that these IgY are polyclonal antibodies since they bind with most venom components. In the neutralizing assay, all mice survived while the ratios of IgY/venom reached up to 3.79 (50.0 mg/13.2 mg).IgY antibody response was successfully conducted in white leghorn chicken injected with T. albolabris venom. IgY against T. albolabris venom was obtained for the first time, and it exhibited strong neutralizing potency on mice. These results may lay a foundation for the development of IgY antivenom with clinical applications in the future.
To investigate the effects of cardiotrophin-1 (CT-1) on differentiation of induced rat bone marrow mesenchymal stem cells (BMMSCs) in vitro with 5-azacytidine (5-aza) for the purpose of elucidation of the cellular biological mechanisms.BMMSCs isolated from femur of rats were divided into four groups: untreated group as control (group A); 0.1 nmol/L CT-1 added to medium (Group B); induced with 10 micromol/L 5-aza only (Group C); induced with 10 micromol/L 5-aza combined with 0.1 nmol/L CT-1 added to medium (Group D). After 4 weeks of induced culturing, the differentiation of induced myocyte like cells were estimated, levels of cardiac troponin-T (cTnT) by immunohistochemical staining and ultrastructure of induce-cultured BMMSCs were determined and mRNA expression of alpha-actin, beta-myosin heavy chain (beta-MHC), Nkx2.5, GATA4 were analyzed by real time polymerase chain reaction (RT-PCR).After 4 weeks of induced culturing, morphological characteristics of myocyte like cells with the expression of cTnT were observed in group C and D cells. Higher level expression of GATA4, Nkx2.5, alpha- actin and beta-MHC mRNA in group D was observed by comparing with those of group C and the differentiated BMMSCs with formations of myofilaments distinctly were also existed in 5-aza combined with CT-1 treatment group.This study suggests that induced culturing of BMMSCs in the presence of 5-aza combined with CT-1 can enhance cardiomyocytic characteristics. CT-1 upregulates the expression of GATA4, Nkx2.5, alpha-actin and beta-MHC mRNA, and rapidly promotes the differentiation and maturation of cardiomyocyte-like cells differentiated from BMMSCs induced with 5-aza.
Glaucocalyxin A is a new diterpenoid isolated from the ethereal extract of the leaves of Rabdosia japonica (Burm f) Hara var glaucocalyx (Maxim) Hara (Labiatae) collected in the northeastern China. When it was incubated with washed rabbit platelets, glaucocalyxin A inhibited ADP- or arachidonic acid-induced platelet aggregation with IC50 values of 4.4 mumol/l, 14.1 mumol/l respectively. Glaucocalyxin A also inhibited PAF-induced aggregation of rabbit platelets which were refractory to ADP and arachidonic acid with an IC50 value of 13.7 mumol/l. Analysis of [3H]-PAF binding showed that glaucocalyxin A prevented [3H]-PAF binding to intact washed rabbit platelets with an IC50 value of 8.16 mumol/l, which was consistent with its inhibition of PAF-induced platelet aggregation.
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