白磷活化研究进展

目前,白磷是工业合成各种有机磷衍生物的主要磷源。传统的方法是用氯气氯化白磷得到PCl_(3),然后再通过盐消除反应使其衍生和功能化。然而,在工业生产过程中用到剧毒氯气以及产生的卤化物废物存在很大安全隐患,同时也会引起环境污染。因此,如何采用无氯化的方式直接实现白磷功能化具有重要的科学研究意义和潜在的应用价值。白磷活化的常用方法有3种,包括有机催化、金属配合物活化和主族元素配合物活化。通过对2010年以来白磷的最新研究进展进行具体的阐述,并对未来进行了展望,旨在为早日实现白磷的无氯转化及其工业化应用提供参考。

Troglitazone inhibits cell proliferation by attenuation of epidermal growth factor receptor signaling independent of peroxisome proliferator-activated receptor γ

Peroxisome proliferator-activated receptors （PPAR） belong to the nuclear hormone receptor superfamily of ligand-dependent transcription factors. Recent results have shown that agonists of PPARy, such as troglitazone （TGZ）, can inhibit cell proliferation and promote cell differentiation independent of PPARy. In the present study, we provide evidence that TGZ may bind directly to EGFR and trigger its signaling and internalization independent of PPARγ. Detailed studies revealed that prolonged incubation with TGZ effectively attenuated EGFR signaling by targeting the receptor to the endo-lysosomal degradation machinery. Although the extracellular signal-regulated kinasesignaling pathway was transiently activated by TGZ in EGFR overexpressing cancer cells, inhibition of EGF-induced Akt phosphorylation most likely accounted for the growth arrest of tumor cells caused by TGZ at pharmacologically achievable concentrations. Therefore, we have provided a new line of evidence indicating that TGZ inhibits cell pro- liferation by promoting EGFR degradation and attenuating Akt phosphorylation.

Regulation of swelling-activated chloride channels in embryonic chick heart cells

Swelling-activated Cl- currents, I(ci,swell), were measured during hyposmotic shock in white Leghorn embryonic chick heart cells using the whole-cell recording of patch-clamp technique. Genistein, an inhibitor of protein tyrosine kinase (PTK), suppressed I(ci,swell), Under isosmotic condition phorbol 12-myristate 13-acetate (PMA), an activator of PKC, elicited the Cl~ current similar to that in hyposmotic solution, whereas hyposmotic shock did not elicit I(ci,swell) in chelerythrine chloride(an inhibitor of PKC)-treated cells. Con-focal microscopy experiments using FITC-phalloidin as a fluorescent label of F-actin showed that the actin network was moved from cortical region of the cell to the center after hyposmotic shock as compared with the image under isosmotic condition. When the cells were treated with cytochalasin B (CB) or cytochalasin D (CD) under isosmotic condition the disruption of the F-actin integrity was observed, and I(ci,Sweii) was not elicited. With combination treatment of CB with PMA, hyposmotic solution could not elicited I(Ci,swell), The results suggested that the role of PTK, probably receptor tyrosine kinase, for regulation of I(ci,sweii) appeared to be at upstream site related to the role of F-actin. Then PKC signal pathway was activated somehow and finally change in the polymerization state of cytoskeleton led to activate the swelling-activated Cl- channels. These results demonstrate clearly that PTK, PKC and F-actin are important factors for regulation of I(Ci,swell) in embryonic chick heart cells as compared with often controversial results reported in different cell types.

IN VITRO ANALYSIS OFτPHOSPHORYLATION SITES AND ITS BIOLOGICAL ACTIVITY

To explore the association between the abnormal phosphorylation sites found in Alzheimer disease (AD) 蚲 and the inhibition of its biological activit y. Methods. Ultracentrifugation, chromatography, manual Edman degradation and autos equence techniques were used to prepare and phosphorylate human recombinant 蚲, isolate and purify 32P 蚲 peptides and determine phosphorylation sites. Results. Phosphorylation of 蚲 by casein kinase 1 (CK 1), cyclic AMP dependent protein kinase (PKA) and glycogen synthetase kinase 3 (GSK 3) separately inhi bited its biological activity and the inhibition of this activity by GSK 3 was significantly increased if 蚲 was prephosphorylated by CK 1 or PKA. The most po tent inhibition was seen by a combined phosphorylation of 蚲 with PKA and GSK 3 . The treatment of 蚲 by PKA and GSK 3 combination induced phosphorylation of 蚲 at Ser 195, Ser 198, Ser 199, Ser 202, Thr 205, Thr 231, Ser 235, Ser 262, Ser 356, Ser 404, whereas Thr 181, Ser 184, Ser 262, Ser 356 and Se r 400 were phosphorylated by GSK 3 alone under the same condition. Conclusion. Phosphorylation of 蚲 by PKA plus GSK 3 at Thr 205 might play a ke y role in 蚲 pathology in AD.

含六磷杂并环[3.1.0]己烷四负离子的三核稀土镥配合物的分离与结构表征（英文）

白磷直接合成有机膦化合物具有重要的科学意义,因为其不仅避免了磷化工生产过程中产生的大量污染,而且可以用于合成许多结构新颖的含磷化合物.从镥杂环戊二烯与白磷的反应中分离并表征了一例新颖的三核稀土金属配合物[{(η^5-C5Me5)LuCl}3(THF)P6][Li(THF)4].该配合物具有一个六磷杂并环[3.1.0]己烷四负离子配体,相比于其他已知的六磷杂己烷类配体,该配体目前仍未被报道.X射线单晶衍射实验表明,该六磷杂并环[3.1.0]己烷四负离子配体采取的船式构象,与三个稀土金属分别以η^1,η^3,η^3的方式配位,形成一个结构新颖的[P6Lu3]笼状结构.密度泛函理论(DFT)计算表明,该化合物在其两侧分别有一个三中心两电子键.

Effect of Yiqihuoxue prescription on myocardial energy metabolism after myocardial infarction via cross talk of liver kinase B1-depen-dent Notch1 and adenosine 5'-monophosphate-activated protein kinase

OBJECTIVE: To investigate the effect of Yiqihuoxue prescription(YQHX) from Traditional Chinese Medicine(TCM) on myocardial glucose and lipid metabolism after myocardial infarction via the cross talk between the liver kinase B1(LKB1)-dependent Notch1 and adenosine 5'-monophosphate(AMP)-activated protein kinase(AMPK). YQHX was prepared with substances with properties that benefit, to activate blood circulation based on the TCM theory.METHODS: Animal models of myocardial infarction were established by ligating Sprague Dawley rats' left anterior descending coronary arteries. The animals were randomly divided into a myocardial infarction(MI) group, a YQHX group, a perindopril group, a γ-secretase inhibitor, Notch signal inhibitor(DAPT) group, a DAPT+YQHX group and a sham group. The related drugs were administered on the second day after operation, and changes in the relevant indexes were examined on weeks 1 and 4.Changes in cardiac structure and function were examined by echocardiography. The glucose and free fatty acids(FFA) were examined by ELISA. The expression of Notch, LKB1 and AMPK m RNA was examined by a real-time fluorescence quantitative method. The expression of glucose transporter 4(GLUT4), and the expression of total acetyl-Co A carboxylase(ACC) and its phosphorylation were examined by western blotting.RESULTS: Compared with the sham group, the expression of Notch, LKB1 and AMPK m RNA in the MI group was lower. Compared with the MI group, the expression of these m RNAs in the YQHX and perindopril groups was higher, and their expression in the DAPT group was lower. At all time points, the protein expression of GLUT4 and p ACC decreased in the MI group. On week 1, the expression of p ACC protein was higher. In the DAPT group, the expression of p ACC protein decreased. Compared with the YQHX group, the expression of p ACC protein in the DAPT + YQHX group was lower. On week 4,compared with the MI group, the expression of GLUT4 protein in the YQHX group and the perindo-pril group was higher. The expression of GLUT4 protein in the DAPT group decreased. Compared with the YQHX group, the expression of GLUT4 protein in the DAPT+YQHX group was lower. There was no significant difference in the expression of ACC protein between the groups.CONCLUSION: YQHX promoted cross talk between the LKB1-dependent Notch1 and AMPK in myocardial tissue after myocardial infarction. Furthermore,it regulated the glucose and lipid metabolism of cardiomyocytes at different time points, thereby ameliorating the cardiac energy metabolism via different mechanisms and protecting the heart.

Crystal structure of the p38α MAP kinase in complex with a docking peptide from TAB1

The mitogen-activated protein kinase (MAPK) p38α is a key regulator in many cellular processes, whose activity is tightly regulated by upstream kinases, phosphatases and other regulators. Transforming growth factor-β activated kinase 1 (TAK1) is an upstream kinase in p38α signaling, and its full activation requires a specific activator, the TAK1-binding protein (TAB1). TAB1 was also shown to be an inducer of p38α's autophosphorylation and/or a substrate driving the feedback control of p38α signaling. Here we determined the complex structure of the unphosphorylated p38α and a docking peptide of TAB1, which shows that the TAB1 peptide binds to the classical MAPK docking groove and induces long-range conformational changes on p38α. Our structural and biochemical analyses suggest that TAB1 is a reasonable substrate of p38α, yet the interaction between the docking peptide and p38α may not be sufficient to trigger trans-autophosphorylation of p38α.

Study on the relationship between relieving energy crisis in myofascial trigger points with An-Pressing manipulation and AMPK/PGC-1α pathway activation

Objective To explore the mechanism of An-Pressing manipulation in relieving energy crisis in chronic myofascial trigger points(MTrPs)by observing the effects of An-Pressing manipulation on adenosine triphosphate(ATP),adenosine 5′-monophosphate(AMP)-activated protein kinase(AMPK)/peroxisome proliferator-activated receptorγcoactivator 1α(PGC-1α)pathway and mitochondrial ultrastructure of skeletal muscle cells in MTrPs rats.Methods Forty-eight male Sprague-Dawley rats were randomly divided into a blank group,a model group,a lidocaine group,and an An-Pressing manipulation group,with 12 rats in each group.The model group,lidocaine group and An-Pressing manipulation group were used to replicate the MTrPs rat model by blunt shock and centrifugal motion method.After modeling,the An-Pressing manipulation group was subjected to 7 times An-Pressing manipulation,once every other day;the lidocaine group was treated with 3 times of injection of lidocaine at the MTrPs,once every 6 d.The blank group and the model group were fed normally without intervention.After the intervention,local muscle tissue was taken to detect the content of ATP and the expression of AMPK,phosphorylated AMPK(phospho-AMPK),PGC-1α,and glucose transporter 4(GluT4),and the ultrastructure of mitochondria was observed under an electron microscope.Results Compared with the blank group,the ATP content in the model group was decreased(P<0.05),the protein expression levels of phospho-AMPK,PGC-1α,and GluT4 and the ratio of phospho-AMPK to AMPK were decreased(P<0.05);under the electron microscope,the number of mitochondria decreased,and they were deformed,small in volume,and had deformed cristae.Compared with the model group,the ATP contents in the An-Pressing manipulation group and the lidocaine group were increased(P<0.05),and the protein expression levels of phospho-AMPK,PGC-1α,and GluT4 and the ratio of phospho-AMPK to AMPK were increased(P<0.05);under the electron microscope,the number of mitochondria increased,the shape and size of the mitochondria were basically normal,and the cristae could be seen.Compared with the lidocaine group,phospho-AMPK and the ratio of phospho-AMPK to AMPK in the An-Pressing manipulation group were increased(P<0.05);under the electron microscope,the numbers of mitochondria were similar,and the shape and size of the mitochondria were basically normal without swelling,and the cristae could be observed.Conclusion An-Pressing manipulation can increase the ATP content in MTrPs tissue,improve the expression levels of PGC-1α and GluT4 proteins and the ratio of phospho-AMPK to AMPK;its mechanism may relate to the activation of AMPK/PGC-1α signaling pathway to promote the repair of mitochondrial damages.