The role of p38 MAPK in acute paraquat-induced lung injury in rats.

CONTEXT: Paraquat (PQ; 1,1'-dimethyl-4,4'-bipyridinium dichloride) is highly toxic and accounts for a large proportion of the herbicide poisonings seen in clinic. The major cause of mortality is respiratory failure. The p38 mitogen-activated protein kinase (MAPK) signal transduction pathway coordinates various cellular stress responses that have been shown to participate in the pathogenesis of PQ-induced lung injury. OBJECTIVE: To evaluate the effect of the specific p38 MAPK inhibitor SB203580 on PQ-induced lung injury and cytokine secretion. METHODS: In groups of 24, rats were treated with PQ, PQ and SB203580 (SB + PQ), SB203580 alone (SB) or normal saline (control group). Six rats from each group were euthanized at 1, 3, 5 or 7 d. Pathology of lung specimens was scored through hematoxylin and eosin staining. Edema in the lung was quantified from wet-to-dry weight ratios. p38 and p-p38MAPK proteins were measured via electrochemiluminescent Western blots. tumor necrosis factor (TNF)-alpha and interleukin-1 beta (IL-1ß) concentrations in lung specimens and bronchoalveolar lavage fluid (BALF) were quantified via enzyme-linked immunosorbent assay. RESULTS: The mortality rate of the SB + PQ group (16.7%) was significantly lower than that of the PQ group (33.3%; p < 0.05). The PQ group had significantly higher pulmonary histology scores, wet-to-dry weight ratios and phosphorylated p-p38 MAPK levels, as well as higher IL-1ß and TNF-alpha levels in BALF and lung tissues, that did the SB + PQ and control groups (p < 0.05, all). CONCLUSION: The data suggest that the p38 MAPK signaling pathway has an important role in regulating the production of IL-1ß and TNF-alpha in PQ-induced lung injury in rats.

BASI, a potent small molecular inhibitor, inhibits glioblastoma progression by targeting microRNA-mediated ß-catenin signaling.

BACKGROUND AND AIMS: The nuclear localization of ß-catenin, a mediator of canonical Wnt signaling, has been indicated in a variety of cancers and is frequently related to tumor progression and metastasis. Therefore, targeting ß-catenin is an attractive therapeutic strategy for cancers. METHODS: Herein, we identified a natural, small molecule inhibitor of ß-catenin signaling, BASI, and evaluated its therapeutic efficacy both in vitro and in orthotopic mouse models of glioma. RESULTS: BASI significantly suppressed proliferation and invasion and induced apoptosis in glioblastoma cells and resulted in the remarkable attenuation of orthotopic tumor growth in vivo. Furthermore, we found that BASI altered the expression of several microRNAs, which mediated the posttranscriptional silencing of ß-catenin expression either directly or indirectly through a von Hippel-Lindau (VHL)-mediated ß-catenin degradation pattern. CONCLUSIONS: Taken together, our findings offer preclinical validation of BASI as a promising new type of ß-catenin inhibitor with a mechanism of inhibition that has broad potential for the improved treatment of glioblastoma.

Aspirin-/TMZ-coloaded microspheres exert synergistic antiglioma efficacy via inhibition of ß-catenin transactivation.

BACKGROUND AND AIMS: Currently temozolomide (TMZ) as a potent agent is widely used to treat the glioblastoma multiforme (GBM), whereas recurrence due to intrinsic or acquired therapeutic resistance often occurs. Combination chemotherapy with TMZ may be a promising therapeutic strategy to improve treatment efficacy. METHODS: Aspirin, TMZ, and aspirin-/TMZ-coloaded poly (L-lactide-co-glycolide) (PLGA) microspheres were prepared by spray drying, and cytotoxicities of glioblastoma cells were measured. RESULTS: Aspirin microsphere treatment induced slight apoptosis and modestly inhibited proliferation of LN229 and U87 cells in vitro and in vivo through inhibition of ß-catenin transactivation. However, aspirin-/TMZ-coloaded microspheres presented synergistic antitumor efficacy compared with single TMZ-loaded microspheres. Aspirin/TMZ microspheres induced more apoptosis and repressed proliferation of LN229 and U87 cells. Corresponding to inhibition of ß-catenin signaling, ß-catenin/TCF4 transcriptional activity and STAT3 luciferase activity were strongly suppressed, and downstream targets expression was decreased. Furthermore, aspirin/TMZ microsphere intratumoral injection downregulated the expression of ß-catenin, TCF4, pAKT, pSTAT3, and PCNA and delayed tumor growth in nude mice harboring subcutaneous LN229 xenografts. CONCLUSIONS: Aspirin sensitized TMZ chemotherapy efficacy through inhibition of ß-catenin transactivation; furthermore, the coloaded microspheres achieved a sustained release action to reduce the TMZ dosage, offering the potential for improved treatment of glioblastomas.

Dichlorido[bis-(2-ethyl-5-methyl-1H-imidazol-4-yl-κN)methane]-cobalt(II) monohydrate.

In the title compound, [CoCl(2)(C(13)H(20)N(4))]·H(2)O, the Co(II) atom lies on a mirror plane and is four-coordinated by two N atoms of the imidazole ligand and two Cl atoms in a distorted tetra-hedral arrangement. The water mol-ecule participates in the formation of hydrogen bonds, resulting in a three dimensional network involving the Cl atoms and the NH groups. The terminal C atom of the ethyl group is disordered over two sites of equal occupancy.

N-(4-Fluoro-benz-yl)-3-nitro-pyridine-2,6-diamine.

In the title compound, C(12)H(11)FN(4)O(2), the pyridine ring is connected to a benzene ring by a -CH(2)-NH(2)- chain. The nitro group is twisted out of the pyridine ring plane [torsion angle O-N-C-C = 10.41 (10)°]. An intramolecular N-H⋯O hydrogen bond occurs. The fluoro-benzene ring is disordered over two positions [occupancy ratio = 0.59 (3):0.41 (3)]. Inter-molecular N-H⋯O and N-H⋯N hydrogen bonds stabilize the crystal structure.

Aqua-[bis-(2-ethyl-5-methyl-1H-imidazol-4-yl-κN)methane]-oxalatocopper(II) dihydrate.

In the title compound, [Cu(C(2)O(4))(C(13)H(20)N(4))(H(2)O)]·2H(2)O, the Cu(II) atom exhibits a distorted square-pyramidal geometry with the two N atoms of the imidazole ligand and the two O atoms of the oxalate ligand forming the basal plane, while the O atom of the coordinated water mol-ecule is in an apical position. The Cu(II) atom is shifted 0.232 (2) Šout of the basal plane toward the water mol-ecule. The asymmetric unit is completed by two solvent water mol-ecules. These water mol-ecules participate in the formation of an intricate three-dimensionnal network of hydrogen bonds involving the coordinated water mol-ecule and the NH groups.

Bis[bis-(2-ethyl-5-methyl-1H-imidazol-4-yl-κN)methane](nitrato-κO,O')nickel(II) nitrate.

In the title compound, [Ni(NO(3))(C(13)H(20)N(4))(2)]NO(3), the Ni(II) ion shows a distorted octa-hedral geometry formed by four N atoms from two bis-(2-ethyl-5-methyl-1H-imidazol-4-yl)methane ligands and two O atoms from a chelating nitrate anion. Three ethyl groups in the complex cation and the O atoms of the uncoordinated nitrate anion are disordered over two sets of positions [occupancy ratios of 0.52 (3):0.48 (3) and 0.63 (3):0.37 (3), respectively]. In the crystal, inter-molecular N-H⋯O hydrogen bonds connect the complex cations into a zigzag chain along [010] and further N-H⋯O hydrogen bonds between the chains and the uncoordinated nitrate anions lead to layers parallel to (100).

Development of transferrin functionalized poly(ethylene glycol)/poly(lactic acid) amphiphilic block copolymeric micelles as a potential delivery system targeting brain glioma.

The aim of present study is to conceive a biodegradable poly(ethylene glycol)-polylactide (PEG-PLA) copolymer nanoparticle which can be surface biofunctionalized with ligands via biotin-avidin interactions and used as a potential drug delivery carrier targeting to brain glioma in vivo. For this aim, a new method was employed to synthesize biotinylated PEG-PLA copolymers, i.e., esterification of PEG with biotinyl chloride followed by copolymerization of hetero-biotinylated PEG with lactide. PEG-PLA nanoparticles bearing biotin groups on surface were prepared by nanoprecipitation technique and the functional protein transferrin (Tf) were coupled to the nanoparticles by taking advantage of the strong biotin-avidin complex formation. The flow cytometer measurement demonstrated the targeting ability of the nanoparticles to tumor cells in vitro, and the fluorescence microscopy observation of brain sections from C6 glioma tumor-bearing rat model gave the intuitive proof that Tf functionalized PEG-PLA nanoparticles could penetrate into tumor in vivo.