Nitro-oleic acid (OA-NO2), acting as anti-inflammatory signaling mediators, are involved in multiple signaling pathways. Lipoprotein-associated phospholipase A2 (Lp-PLA2) is well known as a cardiovascular risk biomarker. Our results showed that OA-NO2 downregulated the expression of Lp-PLA2 in a time- and dose-dependent manner, whereas native OA had no such effect. Furthermore, OA-NO2 could repress Lp-PLA2 expression in the peripheral blood mononuclear cells of apo CIII-transgenic (apo CIII TG) pigs, which exhibited higher Lp-PLA2 expression and activity than did wild-type (WT) pigs. OA-NO2 inhibited Lp-PLA2 expression in macrophages, independent of nitric oxide formation and PPAR?-activation. However, OA-NO2 downregulates Lp-PLA2 by inhibiting the p42/p44 mitogen-activated protein kinase (MAPK) and the nuclear factor ?B (NF?B) pathways. When used to mediate anti-inflammatory signaling, the regulation of inflammatory cytokines and SOD by OA-NO2 might be associated with the reduction of Lp-PLA2. These results suggested that OA-NO2 might exert a vascular-protective effect partially via Lp-PLA2 inhibition.
The aberrant expression of imprinted genes induces parthenogenetic fetal and placental dysplasia, thus leading to failures in embryonic development. Igf2 and H19 are co-expressed in endoderm and mesoderm-derived tissues and play an important role in normal embryo and extraembryonic development. In this study, the expression and methylation of Igf2/H19 in porcine parthenogenetic fetuses and placentas which had grown 28 days was examined first time to further characterize mammalian parthenogenesis. Weight and morphological comparisons were conducted between parthenogenetic embryos on Day 28 and normal fertilized embryos (control). The results indicated that parthenogenetic fetuses and placentas had smaller weights and volumes than those of the control. In addition, quantitative RT-PCR (qRT-PCR) analysis was performed to determine Igf2/H19 expression levels, showing that the expression of H19 was up-regulated, while Igf2 expression was almost undetectable in both parthenogenetic fetuses and placentas. As a potential mechanism underlying this disrupted expression, the methylation of Igf2/H19 DMR3 was detected using bisulfite sequencing PCR analysis, which revealed the significant hypomethylation of DMR3 in parthenogenetic fetuses and placentas. These results suggest that disruption of Igf2/H19 expression in parthenogenetic fetuses and placentas contributes to implantation failure and/or abortion in swine parthenogenesis, which might be associated with differential methylation patterns in the imprinting control region of imprinted genes.
In this study, we reported millepachine (MIL), a novel chalcone compound for the first time isolated from Millettia pachycarpa Benth (Leguminosae), induced cell cycle arrest and apoptosis in human hepatocarcinoma cells in vitro and in vivo. In in vitro screening experiments, MIL showed strong antiproliferation activity in several human cancer cell lines, especially in HepG2 cells with an IC50 of 1.51 µM. Therefore, we chose HepG2 and SK-HEP-1 cells to study MILs antitumor mechanism. Flow cytometry showed that MIL induced a G2/M arrest and apoptosis in a dose-dependent manner. Western blot demonstrated that MIL-induced G2/M arrest was correlated with the inhibition of cyclin-dependent kinase 1 activity, including a remarkable decrease in cell division cycle (cdc) 2 synthesis, the accumulation of phosphorylated-Thr14 and decrease of phosphorylation at Thr161 of cdc2. This effect was associated with the downregulation of cdc25C and upmodulation of checkpoint kinase 2 in response to DNA damage. MIL also activated caspase 9 and caspase 3, and significantly increased the ratio of Bax/Bcl-2 and stimulated the release of cytochrome c into cytosol, suggesting MIL induced apoptosis via mitochondrial apoptotic pathway. Associated with those effects, MIL also induced the generation of reactive oxygen species. In HepG2 tumor-bearing mice models, MIL remarkably and dose dependently inhibited tumor growth. Treatment of mice with MIL (20mg/kg intravenous [i.v.]) caused more than 65% tumor inhibition without cardiac damage compared with 47.57% tumor reduction by 5mg/kg i.v. doxorubicin with significant cardiac damage. These effects suggested that MIL and its easily modified structural derivative might be a potential lead compound for antitumor drug.
Our previous report has shown a natural pyranochalcones-derived compound, (E)-3-(3,4-Dimethoxyphenyl)-1-(5-hydroxy-2,2-dimethyl-2H-chromen-6-yl)prop-2-en-1-one (5b), that exerted protection against carrageenan-induced hind paw edema and adjuvant-induced arthritis. In this study, collagen-induced arthritis (CIA) model was used to further examine the anti-arthritic effects of 5b in vivo; the underlying molecular mechanisms of action were also investigated using a murine monocytic cell line, RAW264.7 cells. Here we showed that oral administration of 5b (20mg/kg) significantly suppressed the progression of arthritis. Improvement in disease severity was accompanied by inhibition of CD68-positive cells in knee joint and reduced pro-inflammatory cytokines TNF-?, IL-1? and IL-6 in serum. In vitro, 5b suppressed expressions of iNOS, cyclooxygenase-2 (COX-2), TNF-?, IL-6 and IL-1? as well as productions of nitric oxide (NO) and prostaglandin E2 (PGE2) in lipopolysaccharide (LPS)-treated macrophages. This compound also significantly suppressed LPS-induced NF-?B activation, including phosphorylation of I-?B, degradation of I-?B, and nuclear translocation of p65 and p50. Treatment with 5b also blocked LPS-induced expression of TLR4 remarkably, suppressed degradation of IRAKs and phosphorylations of JNK and ERK, but had little effect to p38 kinase activation. These findings indicated that 5b might be a therapeutic agent for rheumatoid arthritis, and exerted an anti-inflammatory effect mainly through mediating TLR4, NF-?B and ERK/JNK signaling pathways in monocytes.
A series of novel tubulin polymerization inhibitors (9a-9p) have been synthesized and evaluated for their in vitro and in vivo biological activities. Among these compounds, 9e displayed strong antiproliferative activity against several tumor cell lines (IC50=0.15-0.62?M). Compound 9e was also shown to arrest cells in the G2/M phase of the cell cycle and inhibit the polymerization of tubulin. Molecular docking studies suggested that 9e binds into the colchicine binding site of tubulin. In xenograft experiments, 9e exerted more potent anticancer effect than anticancer drug taxol against the H460 Human lung carcinoma in BALB/c nude mice. In summary, these findings suggest that 9e is a promising new antimitotic compound for the potential treatment of cancer.
Twenty-five novel pyranochalcone derivatives were synthesized and evaluated for their in vitro and in vivo antiproliferative activities. Among them, compound 10i exhibited superior potent activity against 21 tumor cell lines including multidrug resistant phenotype with the IC50 values ranged from 0.09 to 1.30 ?M. In addition, 10i significantly induced cell cycle arrest in G2/M phase, promoted tubulin polymerization into microtubules and caused microtubule stabilization. Further studies confirmed that 10i significantly suppressed the growth of tumor volume in HepG2 xenograft tumor model. Our study demonstrated that 10i could have beneficial antitumor activity as a novel microtubule stabilizing agent.
Parthenogenetic embryos are invariably lost in mid-gestation, possibly due to the lack of the paternal genome and the consequent induction of aberrant gene expression. Wnt signaling is essential for embryonic development; however, the studies of this pathway in porcine parthenogenetic embryos have been limited. Here, the role of Wnt signaling in porcine parthenogenetic embryos was studied. In vivo embryos were used as controls. Single cell quantitative real-time PCR showed that Wnt signaling was down-regulated in porcine parthenogenetic embryos. Furthermore, immunofluorescence staining and real-time PCR demonstrated that porcine parthenogenetic embryo development was largely unaffected by the inhibition of Wnt signaling with IWP-2, but blastocyst hatching and trophectoderm development was blocked. In addition, parthenogenetic blastocyst hatching was improved by the activation of Wnt signaling by BIO. However, the developmental competency of porcine embryos, including blastocyst hatching, was impaired and apoptosis was induced upon the excessive activation of Wnt signaling. These findings constitute novel evidence that Wnt signaling is important for porcine pre-implantation development and that its down-regulation may lead to the low hatching rate of porcine parthenogenetic blastocysts.
MicroRNAs (miRNAs) regulate various biological processes, but evidence for miRNAs that control the differentiation program of specific neural cell types has been elusive. To determine the role of miRNAs in the formation of myelinating oligodendrocytes, we selectively deleted a miRNA-processing enzyme, Dicer1, in oligodendrocyte lineage cells. Mice lacking Dicer1 display severe myelinating deficits despite an expansion of the oligodendrocyte progenitor pool. To search for miRNAs responsible for the induction of oligodendrocyte maturation, we identified miR-219 and miR-338 as oligodendrocyte-specific miRNAs in spinal cord. Overexpression of these miRNAs is sufficient to promote oligodendrocyte differentiation. Additionally, blockage of these miRNA activities in oligodendrocyte precursor culture and knockdown of miR-219 in zebrafish inhibit oligodendrocyte maturation. miR-219 and miR-338 function in part by directly repressing negative regulators of oligodendrocyte differentiation, including transcription factors Sox6 and Hes5. These findings illustrate that miRNAs are important regulators of oligodendrocyte differentiation, providing new targets for myelin repair.
In this paper, 38 millepachine derivatives have been designed, synthesized and evaluated for their in vitro and in vivo antiproliferative activity. Among these novel derivatives, 15 displayed more potent antiproliferative activity than millepachine against HepG2, K562, SK-OV-3, HCT116, HT29, and SW620 tumor cells (mean IC(50) = 0.64 vs. 2.86 ?M, respectively). Furthermore, 15 could effectively inhibit tubulin polymerization in HepG2 cells, and induce the HepG2 cell cycle arrest at the G2/M phase in a concentration-dependant manner. Further studies confirmed that 15 significantly suppressed the growth of tumor volume and exerted more potent anticancer potency than millepachine and anticancer drug cisplatin in A549 lung xenograft tumor model.
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