ABSTRACT
Objective: To investigate the effects of glycogen synthase kinase-3β (GSK3β)/eukaryotic extension factor kinase 2 (eEF2K) signaling pathway on the process of pulmonary fibrosis through in vivo experiments, and find new ideas for clinical treatment of pulmonary fibrosis. Methods: The pulmonary fibrosis model of C57BL/6 male mice was induced by bleomycin with intratracheal injection at the dose of 2 mg/kg. After 14 days of modeling, animals were divided into model group, negative inhibition group and inhibition group (n=5 for each group), and control group was not processed. The inhibition group was treated with TDZD-8 (4 mg/kg) after modeling, the negative inhibition group was given DMSO solution after modeling, and the samples were collected after 28 days. Hematoxylin-eosin staining method was used to detect lung fibrosis in mice and scored according to Ashcroft scale. Expression levels of GSK3β, p-GSK3β, eEF2K, p-eEF2K (Ser70, Ser392, Ser470), precursor protein of matrix metalloproteinase-2 (pro-MMP-2), matrix metalloproteinase-2 (MMP-2), collagen I (Col I), collagen Ⅲ (Col Ⅲ) and α-smooth muscle actin (α-SMA) were detected by Western blot. Results: Compared with control group, the fibrosis score was up-regulated, the expression levels of GSK3β, p-GSK3β, p-eEF2K (Ser70, Ser392, Ser470), pro-MMP-2, MMP-2, Col I, Col Ⅲ and α-SMA were increased, while that of eEF2K was decreased in model group (P＜0.05). Compared with model group, the fibrosis score, expression levels of GSK3β, p-GSK3β, p-eEF2K (Ser70, Ser392, Ser470), pro-MMP-2, MMP-2, Col I, Col Ⅲ and α-SMA were decreased, but the expression level of eEF2K was increased in inhibition group (P＜0.05). Conclusion: GSK3β can activate eEF2K by phosphorylation at the sites of Ser70, Ser392 and Ser470, increase the contents of fibrosis indicators, promote the formation of pulmonary fibrosis, and aggravate lung tissue lesions.
Subject(s)
Animals , Male , Mice , Collagen , Collagen Type I , Elongation Factor 2 Kinase/metabolism , Eukaryota/metabolism , Fibrosis , Glycogen Synthase Kinase 3 beta , Matrix Metalloproteinase 2/metabolism , Mice, Inbred C57BL , Pulmonary Fibrosis/chemically induced , Signal TransductionABSTRACT
OBJECTIVE： To screen potential eEF2K inhibitor molecules， and to provide reference for the design and R&D of eEF2K inhibitor. METHODS： The eEF2K crystal structure model was constructed by homology modeling technique. The model was optimized by Loop optimization and molecular dynamics. With the help of SAVES online server， the above models were evaluated from three aspects such as Verify_3D， EERAT and Laplace diagram. Totally 55 eEF2K inhibitor molecules were collected. Hypogen pharmacophore model with activity prediction ability was constructed based on 28 of them （odd number， as training set） by Insight Ⅱ software and validated by other 27 （even number， as test set）. The optimal pharmacophore model was screened by fitting the predicted and experimental values of activity [i.e. negative logarithm of half inhibitory concentration （pIC50）] and using Ligand profiler thermogram. The virtual screening of small molecules of eEF2K inhibitors was carried out by combining the above pharmacophore model， Lipinski’s five rules and molecular docking method. RESULTS & CONCLUSIONS： The overall quality factor score of the crystal structure model of eEF2K protein was 93.697. Among them， 83.33％ of the amino acid Verify_3D score was more than or equal to 0.2， and 1.7％ of the total amino acids were located in the non-permissible region. The amino acid conformation and skeleton structure of the model were reasonable and the reliability of the model was high. Totally 9 Hypogen pharmacophore models （No. 02-10） with active predictive function were constructed， among which No. 03 pharmacophore model included 2 hydrogen bond receptors and 2 conjugated aromatic rings， which could better distinguish active and inactive molecules. The predicted value of pIC50 fitted the experimental value best （the correlation coefficient was 0.665 3）， and it had good predictive ability and high reliability. Finally， 9 potential eEF2K inhibitor molecules were obtained through virtual screening （pIC50 ranged from 1.074 to 1.185， and Dcoking-score of protein-molecule interaction ranged from －9.730 to －7.467）. Pro268， Asp267， Gln171， Phe121 and Glu212 may be the key amino acids for the interaction between eEF2K inhibitors and target proteins， including hydrogen bonds， salt bridges and hydrophobicity. These 9 molecules are expected to be the lead compounds for the development of eEF2K inhibitors.
ABSTRACT
Aim To identify whether the petroleum e-ther fraction of Gardenia jasminoides Ellis ( GJ-PE ) could effetive exhibit a rapid antidepressant effect and also to investigate the biological mechanism. Methods Tail suspension test ( TST ) , forced swimming test ( FST ) and novelty suppressed-feeding ( NSF ) were used to screen the rapid antidepressant potential of ef-fective fractions of GJ-PE in KM mice at 24 h post a single administration. Tail suspension test ( TST) was also used at 30 min and forced swimming test ( FST ) was used at 2 h to test the initial onset time of effective fractions of GJ-PE in KM mice. Western blot was per-formed to examine the expression of BDNF and p-eEF2 in hippocampus of KM mice at 2 h and 24 h. Results An acute administration of GJ-PE1 decreased the im-mobility time of KM mice in FST at 2 h and 24 h and decreased the latency time in NSF at 24 h. GJ-PE3 de-creased the latency time in NSF at 24 h. GJ-PE4 in-creased the unit food consumption in NSF at 24 h. At 2 h post a single GJ-PE1 treatment, the expression of BDNF was significantly up-regulated while the expres-sion of p-eEF2 was significantly down-regulated. At 24 h post a single GJ-PE1 treatment, the expression of BDNF was significantly down-regulated while p-eEF2 expression was significantly up-regulated. Conclusion GJ-PE1 has the most significant rapid antidepressant potential among the four fractions of GJ-PE. The effec-tive time of GJ-PE1 is 2 h after drug treatment. The mechanism of the rapid antidepressant effect of GJ-PE1 at 2 h is related to the up-regulation of BDNF and down-regulation of p-eEF2 . GJ-PE3 and GJ-PE4 also have some features of rapid antidepressants. GJ-PE2 doesn′t have the rapid antidepressant potential.
ABSTRACT
Eukaryotic elongation factor 2 kinase (eEF2K) inhibitors may aid in the development of new therapeutic agents to combat cancer. Purified human eEF2K was obtained from anexpression system and a luminescence-based high-throughput screening (HTS) assay was developed using MH-1 peptide as the substrate. The luminescent readouts correlated with the amount of adenosine triphosphate remaining in the kinase reaction. This method was applied to a large-scale screening campaign against a diverse compound library and subsequent confirmation studies. Nine initial hits showing inhibitory activities on eEF2K were identified from 56,000 synthetic compounds during the HTS campaign, of which, five were chosen to test their effects in cancer cell lines.
ABSTRACT
Eukaryotic elongation factor eEF-2 mediates regulatory steps important for the overall regulation of mRNA translation in mammalian cells and is activated by variety of cellular conditions and factors. In this study, eEF-2 specific, Ca2+/CaM-dependent protein kinase III (CaM PK III), also called eEF-2 kinase, was examined under oxidative stress and cell proliferation state using CHO cells. The eEF-2 kinase activity was determined in the kinase buffer containing Ca2+ and CaM in the presence of eEF-2 and [gamma-32P] ATP. The eEF-2 kinase activity in cell lysates was completely dependent upon Ca2+ and CaM. Phosphorylation of eEF-2 was clearly identified in proliferating cells, but not detectable in CHO cells arrested in their growth by serum deprivation. The content of the eEF-2 protein, however, was equivalent in both cells. Using a phosphorylation state-specific antibody, we show that oxidant such as H2O2, which triggers a large influx of Ca2+, dramatically enhances the phosphorylation of eEF-2. In addition, H2O2-induced eEF-2 phosphorylation is dependent on Ca2+ and CaM, but independent of protein kinase C. In addition, okadaic acid inhibits phosphoprotein phosphatase 2A(PP2A)-mediated eEF-2 dephosphorylation. These results may provide a possible link between the elevation of intracellular Ca2+ and cell division and suggest that phosphorylation of eEF-2 is sensitive cellular reflex on stimuli that induces intracellular Ca2+ flux.