A novel alpha 7 nAChR agonist, 4-(5-methyloxazolo4,5-bpyridin-2-yl)-1,4-diazabicyclo3.2.2nonane (24, CP-810,123), has been identified as a potential treatment for cognitive deficits associated with ...psychiatric or neurological conditions including schizophrenia and Alzheimer's disease. Compound 24 is a potent and selective compound with excellent pharmaceutical properties. In rodent, the compound displays high oral bioavailability and excellent brain penetration affording high levels of receptor occupancy and in vivo efficacy in auditory sensory gating and novel object recognition. The structural diversity of this compound and its preclinical in vitro and in vivo package support the hypothesis that alpha 7 nAChR agonists may have potential as a pharmacotherapy for the treatment of cognitive deficits in schizophrenia.
A novel α7 nAChR agonist, 4-(5-methyloxazolo4,5-bpyridin-2-yl)-1,4-diazabicyclo3.2.2nonane (24, CP-810,123), has been identified as a potential treatment for cognitive deficits associated with ...psychiatric or neurological conditions including schizophrenia and Alzheimer’s disease. Compound 24 is a potent and selective compound with excellent pharmaceutical properties. In rodent, the compound displays high oral bioavailability and excellent brain penetration affording high levels of receptor occupancy and in vivo efficacy in auditory sensory gating and novel object recognition. The structural diversity of this compound and its preclinical in vitro and in vivo package support the hypothesis that α7 nAChR agonists may have potential as a pharmacotherapy for the treatment of cognitive deficits in schizophrenia.
Digitized video fluorescent microscopy (DVFM) is a powerful technique for quantitating multiple processes in living cells. However, techniques for measuring protease activity by DVFM are not ...available. Our aim was to develop an approach for measuring aminopeptidase activity using DVFM. We conjugated glycine-7-amino-4-methylcoumarin-3-acetic acid (glycine-AMC-3-acetic acid) to dextran using a PEG bridge. Glycine-AMC-3-acetic acid-PEG-dextran was microinjected into cultured rat hepatocytes along with rhodamine-dextran. Glycine-AMC-3-acetic acid-PEG-dextran is nonfluorescent, but aminopeptidase hydrolysis of the glycine-AMC bond liberates the fluorescent AMC-3-acetic acid-PEG-dextran within the cell. Following microinjection, rhodamine-dextran fluorescence remained constant while AMC-3-acetic acid-PEG-dextran fluorescence increased in a linear fashion over time reflecting proteolytic cleavage of the glycine-AMC bond. AMC-3-acetic acid-PEG-dextran and rhodamine-dextran fluorescence were cytosolic as evidenced by diffuse fluorescence and colocalized. Because rhodamine-dextran fluorescence remained constant and the probes colocalized, the fluorescent ratio of AMC-3-acetic acid-PEG-dextran/rhodamine-dextran could be used to measure proteolysis. Basal rates of proteolysis were 9 +/- 3 ratio units/10 min. Comicroinjection of the aminopeptidase inhibitor, bestatin, along with the dextran probes abolished proteolysis. Addition of the calcium ionophore, 4-Br-A23187, increased proteolysis 12-fold to 107 +/- 14/10 min (P < 0.01). We have developed a novel, dynamic technique for measuring pH-sensitive, Ca(2+)-dependent aminopeptidase activity in living cells using DVFM. This approach may be used for the measurement of other peptidase activities by synthesizing peptidase-specific peptidyl-AMC-3-acetic acid-PEG-dextran conjugates.
The characterization of biomolecules from ancient samples can shed otherwise unobtainable insights into the past. Despite the fundamental role of transcriptomal change in evolution, the potential of ...ancient RNA remains unexploited - perhaps due to dogma associated with the fragility of RNA. We hypothesize that seeds offer a plausible refuge for long-term RNA survival, due to the fundamental role of RNA during seed germination. Using RNA-Seq on cDNA synthesized from nucleic acid extracts, we validate this hypothesis through demonstration of partial transcriptomal recovery from two sources of ancient maize kernels. The results suggest that ancient seed transcriptomics may offer a powerful new tool with which to study plant domestication.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
MicroRNAs regulate pathways contributing to oncogenesis, and thus the mechanisms causing dysregulation of microRNA expression in cancer are of significant interest. Mature mir-29b levels are ...decreased in malignant cells, and this alteration promotes the malignant phenotype, including apoptosis resistance. However, the mechanism responsible for mir-29b suppression is unknown. Here, we examined mir-29 expression from chromosome 7q32 using cholangiocarcinoma cells as a model for mir-29b downregulation. Using 5′ rapid amplification of cDNA ends, the transcriptional start site was identified for this microRNA locus. Computational analysis revealed the presence of two putative E-box (Myc-binding) sites, a Gli-binding site, and four NF-κB-binding sites in the region flanking the transcriptional start site. Promoter activity in cholangiocarcinoma cells was repressed by transfection with c-Myc, consistent with reports in other cell types. Treatment with the hedgehog inhibitor cyclopamine, which blocks smoothened signaling, increased the activity of the promoter and expression of mature mir-29b. Mutagenesis analysis and gel shift data are consistent with a direct binding of Gli to the mir-29 promoter. Finally, activation of NF-κB signaling, via ligation of Toll-like receptors, also repressed mir-29b expression and promoter function. Of note, activation of hedgehog, Toll-like receptor, and c-Myc signaling protected cholangiocytes from TRAIL-induced apoptosis. Thus, in addition to c-Myc, mir-29 expression can be suppressed by hedgehog signaling and inflammatory pathways, both commonly activated in the genesis of human malignancies.
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