Synthesis and biological evaluation of novel N-(piperazin-1-yl)alkyl-1H-dibenzo[a,c]carbazole derivatives of dehydroabietic acid as potential MEK inhibitors.

In this paper, a series of novel 1H-dibenzo[a,c]carbazole derivatives of dehydroabietic acid bearing different N-(piperazin-1-yl)alkyl side chains were designed, synthesised and evaluated for their in vitro anticancer activities against three human hepatocarcinoma cell lines (SMMC-7721, HepG2 and Hep3B). Among them, compound 10g exhibited the most potent activity against three cancer cell lines with IC50 values of 1.39 ± 0.13, 0.51 ± 0.09 and 0.73 ± 0.08 µM, respectively. In the kinase inhibition assay, compound 10g could significantly inhibit MEK1 kinase activity with IC50 of 0.11 ± 0.02 µM, which was confirmed by western blot analysis and molecular docking study. In addition, compound 10g could elevate the intracellular ROS levels, decrease mitochondrial membrane potential, destroy the cell membrane integrity, and finally lead to the oncosis and apoptosis of HepG2 cells. Therefore, compound 10g could be a potent MEK inhibitor and a promising anticancer agent worthy of further investigations.

Bone-derived Nestin-positive mesenchymal stem cells improve cardiac function via recruiting cardiac endothelial cells after myocardial infarction.

BACKGROUND: Bone-derived mesenchymal stem cell (BMSC) transplantation has been reported to be effective for the treatment of ischemic heart disease, but whether BMSCs are the optimal cell type remains under debate. Increasing numbers of studies have shown that Nestin, an intermediate filament protein, is a potential marker for MSCs, which raises the question of whether Nestin+ cells in BMSCs may play a more crucial role in myocardial repair. METHODS: Nestin+ cells were isolated using flow cytometry by gating for CD45- Ter119- CD31- cells from the compact bone of Nestin-GFP transgenic mice, expressing GFP driven by the Nestin promoter. Colony-forming and proliferative curve assays were conducted to determine the proliferative capacity of these cells, while qRT-PCR was used to analyze the mRNA levels of relative chemokines and growth factors. Cardiac endothelial cell (CEC) recruitment was assessed via a transwell assay. Moreover, permanent ligation of the left anterior descending (LAD) coronary artery was performed to establish an acute myocardial infarction (AMI) mouse model. After cell transplantation, conventional echocardiography was conducted 1 and 4 weeks post-MI, and hearts were harvested for hematoxylin-and-eosin (HE) staining and immunofluorescence staining 1 week post-MI. Further evaluation of paracrine factor levels and administration of a neutralizing antibody (TIMP-1, TIMP-2, and CXCL12) or a CXCR4 antagonist (AMD3100) in MI hearts were performed to elucidate the mechanism involved in the chemotactic effect of Nestin+ BMSCs in vivo. RESULTS: Compared with Nestin- BMSCs, a greater proliferative capacity of Nestin+ BMSCs was observed, which further exhibited moderately high expression of chemokines instead of growth factors. More CEC recruitment in the Nestin+ BMSC-cocultured group was observed in vitro, while this effect was obviously abolished after treatment with neutralizing antibodies against TIMP-1, TIMP-2, or CXCL12, and more importantly, blocking the CXCL12/CXCR4 axis with a AMD3100 significantly reduced the chemotactic effect of Nestin+ BMSCs. After transplantation into mice exposed to myocardial infarction (MI), Nestin+ BMSC-treated mice showed significantly improved survival and left ventricular function compared with Nestin- BMSC-treated mice. Moreover, endogenous CECs were markedly increased, and chemokine levels were significantly higher, in the infarcted border zone with Nestin+ BMSC treatment. Meanwhile, neutralization of each TIMP-1, TIMP-2, or CXCL12 in vivo could reduce the left ventricular function at 1 and 4 weeks post-MI; importantly, the combined use of these three neutralizing antibodies could make a higher significance on cardiac function. Finally, blocking the CXCL12/CXCR4 axis with AMD3100 significantly reduced the left ventricular function and greatly inhibited Nestin+ BMSC-induced CEC chemotaxis in vivo. CONCLUSIONS: These results suggest that Nestin+ BMSC transplantation can improve cardiac function in an AMI model by recruiting resident CECs to the infarcted border region via the CXCL12/CXCR4 chemokine pathway. And we demonstrated that Nestin+BMSC-secreted TIMP-1/2 enhances CXCL12(SDF1α)/CXCR4 axis-driven migration of endogenous Sca-1+ endothelial cells in ischemic heart post-AMI. Taken together, our results show that Nestin is a useful marker for the identification of functional BMSCs and indicate that Nestin+ BMSCs could be a better therapeutic candidate for cardiac repair.

Recovery cycle of inferior collicular neurons in Hipposideros pratti under behavior-related sound stimulus and the best Doppler-shift compensation conditions.

The Doppler-shift compensation (DSC) behavior of constant frequency - frequency modulation (CF-FM) bat (Hipposideros pratti) is vital for extraction and analysis of echo information. This type of behavior affects the recovery cycles of sound-sensitive neurons, but their precise relationship remains unclear. In this study, we investigated the effects of DSC on the recovery cycles of inferior collicular (IC) neurons in H. pratti. We simulated the pulse-echo pair in bats by changing the emitted pulse frequency and keeping the echo frequency constant during DSC in echolocation. The neuronal recovery cycles of IC neurons are categorized into four types: unrecovered, monotonic, single-peak, and multi-peak. The recovery cycle of IC neurons shortens after DSC; moreover, the amount of neurons with multi-peak recovery cycle increases and concentrates in the short recovery area. This paper also discusses the possible neural mechanisms and their biological relevance to different phases of bat predation behavior.

Expression and significance of Wnt signaling components and their target genes in breast carcinoma.

The aim of this study was to investigate the expression of ß-catenin, axin, cyclin D1 and c-myc, and their correlation with various clinicopathological factors of breast carcinoma. Using immunohistochemistry, the expression of axin, ß-catenin, cyclin D1 and c-myc proteins was detected in 168 breast carcinomas and 40 normal breast tissue samples, as well as in 72 breast intraductal proliferative lesions. Correlations among the expression of these proteins with the clinicopathological factors of breast carcinomas were subsequently analyzed. Gene mutations of ß-catenin (exon 3) in 44 cases of breast carcinoma were analyzed using polymerase chain reaction (PCR) followed by direct sequencing. In normal tissue, the epithelial cells demonstrated a marked membranous expression of ß-catenin protein at cell-cell boundaries and positive axin expression; cyclin D1 and c-myc expression, however, were negative. The abnormal rate of ß-catenin expression and the overexpression of cyclin D1 and c-myc were higher in breast carcinomas compared with breast cystic hyperplasia tissues. Positive axin expression levels were lower in breast carcinomas compared with breast intraductal proliferative lesions and normal breast tissues. Axin expression correlated inversely with tumor size, histological grade, clinical tumor, node, metastasis (TNM) stage and lymph node metastasis. The abnormal expression of ß-catenin and the overexpression of cyclin D1 were correlated, and the overexpression of c-myc was correlated with tumor size, histological grade, clinical TNM stage and lymph node metastasis. The abnormal expression of ß-catenin was correlated with the overexpression of cyclin D1, but not with the overexpression of c-myc. Lower levels of axin expression were correlated with higher levels of nuclear ß-catenin expression. Mutations in the ß-catenin gene were not detected in 44 cases of breast carcinoma. The abnormal expression of ß-catenin may be key in the carcinogenesis and progression of human breast carcinoma by upregulating the expression of cyclin D1. The abnormal expression of ß-catenin, the reduced expression of axin, and the overexpression of cyclin D1 and c-myc may be useful markers for determining metastasis, providing a prognosis for human breast carcinoma and for guiding treatment.

Synthesis and biological evaluation of novel N-substituted 1H-dibenzo[a,c]carbazole derivatives of dehydroabietic acid as potential antimicrobial agents.

A series of new N-substituted 1H-dibenzo[a,c]carbazole derivatives were synthesized from dehydroabietic acid, and their structures were characterized by IR, (1)H NMR and HRMS spectral data. All compounds were evaluated for their antibacterial and antifungal activities against four bacteria (Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas fluorescens) and three fungi (Candida albicans, Candida tropicalis and Aspergillus niger) by serial dilution technique. Some of the synthesized compounds displayed pronounced antimicrobial activity against tested strains with low MIC values ranging from 0.9 to 15.6µg/ml. Among them, compounds 6j and 6r exhibited potent inhibitory activity comparable to reference drugs amikacin and ketoconazole.

Furandiones from an endophytic Aspergillus terreus residing in Malus halliana.

Two new furandiones named asperterone B (1) and C (2) together with four known metabolites (3-6) were isolated from the liquid culture of the endophytic fungus Aspergillus terreus MHL-P22 residing in the fresh leaves of Malus halliana. The structures of the new compounds were elucidated by analysis of their MS, IR, 1D- and 2D-NMR spectra. 1 and 2 showed moderate cytotoxic activities against human colorectal carcinoma SW1116 cells with IC(50) values of 57.5 and 71.0 µM, respectively. The biosynthetic pathway for 1, 2 and their analogues was also postulated and briefly discussed.

N-(4-Bromo-phen-yl)-3,4,5-trimeth-oxy-benzamide.

In the title compound, C(16)H(16)BrNO(4), the dihedral angle between the two aromatic rings is 67.51 (25)°. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds involving the N-H and C=O groups of the amide function, leading to a chain along [-101].