Quality analysis of Rosae Radix et Rhizoma / 中国中药杂志

Rosae Radix et Rhizoma is a herbal medicine in a variety of famous Chinese patent medicines, while the quality standard for this medicine remains to be developed due to the insufficient research on the quality of Rosae Radix et Rhizoma from different sources. Therefore, this study comprehensively analyzed the components in Rosae Radix et Rhizoma of different sources from the aspects of extract, component category content, identification based on thin-lay chromatography, active component content determination, and fingerprint, so as to improve the quality control. The results showed that the content of chemical components varied in the samples of different sources, while there was little difference in the chemical composition among the samples. The content of components in the roots of Rosa laevigata was higher than that in the other two species, and the content of components in the roots was higher than that in the stems. The fingerprints of triterpenoids and non-triterpenoids were established, and the content of five main triterpenoids including multiflorin, rosamultin, myrianthic acid, rosolic acid, and tormentic acid in Rosae Radix et Rhizoma was determined. The results were consistent with those of major component categories. In conclusion, the quality of Rosae Radix et Rhizoma is associated with the plant species, producing area, and medicinal parts. The method established in this study lays a foundation for improving the quality standard of Rosae Radix et Rhizoma and provides data support for the rational use of the stem.

Investigation on in Vitro Antioxidant Activity and Chemical Composition of Different Polar Parts of Extract of Rosa cymosa Roots / 中国实验方剂学杂志

Objective:To investigate the antioxidant activity and chemical composition of 75% ethanol extract of <italic>Rosa cymosa</italic> roots and its different polar parts. Method:The 75% ethanol extract of <italic>R. cymosa</italic> roots was divided into dichloromethane， ethyl acetate， <italic>n</italic>-butanol and water parts by organic solvent extraction. <italic>In vitro</italic> antioxidant activity of each fraction was determined by 1，1-diphenyl-2-picrylhydrazyl （DPPH） and 2，2'-azino-bis（3-ethylbenzothiazoline-6-sulfonic acid） （ABTS） free radical scavenging assays， as well as ferric reducing antioxidant power （FRAP） test. The contents of total triterpenes， total phenols， total tannins and condensed tannins in each fraction were determined by spectrophotometry. SPSS 24.0 software was used to conduct Pearson correlation analysis between the antioxidant activity of each fraction and the content of the main components， and then the main active fraction and the main active components were determined. The chemical constituents of the active fraction was analyzed by ultra performance liquid chromatography-quadrupole-time-of-flight mass spectrometry （UPLC-Q-TOF-MS/MS）， and the structures of the main chromatographic peaks were predicted. Result:Each fraction of <italic>R. cymosa</italic> roots had certain antioxidant activity， and there was a significant dose-effect relationship within a certain concentration range， but the antioxidant activity of different polar parts was different. In DPPH and ABTS free radical scavenging tests， the antioxidant activity of each fraction and vitamin C （VC， the positive drug） was ranked as ethyl acetate fraction>VC><italic>n</italic>-butanol fraction>ethanol extract>water fraction>dichloromethane fraction. In FRAP test， the activity of ethyl acetate fraction was weaker than that of VC， and the other order was unchanged. The contents of total triterpenes， total phenols， total tannins and condensed tannins in ethyl acetate fraction were 3.81%， 50.33%， 3.32%， and 39.79%， in <italic>n</italic>-butanol fraction were 0.88%， 41.42%， 2.25% and 23.55%， in ethanol extract were 2.90%， 41.95%， 3.43% and 20.14%， in water fraction were 0， 26.80%， 16.90% and 7.57%， and in dichloromethane fraction were 21.23%， 12.90%， 1.59%， and 6.17%， respectively. Correlation analysis results showed that the contents of total phenols and condensed tannins were positively correlated with the antioxidant activity， the contents of total triterpenes were negatively correlated with the antioxidant activity， and the correlation between total tannins and antioxidant activity was not obvious. A total of 26 compounds were identified from the ethyl acetate fraction by UPLC-Q-TOF-MS/MS， including 11 condensed tannins， 4 hydrolysable tannins， 6 triterpenes， 3 flavonoids， 1 benzoic acid derivative and 1 chlorogenic acid analogue. Conclusion:Ethyl acetate fraction is the main antioxidant active site of <italic>R. cymosa</italic> roots， and phenols mainly composed of condensed tannins are the main active components. The results can provide experimental basis for the development of natural antioxidants.

Research progress of tannins in traditional Chinese medicines in recent ten years / 中国中药杂志

In this paper, the newly isolated tannins were sorted after a review of the literature concerning tannins in recent 10 years, and their research progress was summarized in terms of extraction, isolation, pharmacological activity and metabolism. Hydrolysable tannins and condensed tannins are the main structural types. Modern research shows that tannins have many pharmacological effects, such as bacteriostasis, antioxidation, antitumor, antivirus and blood glucose reduction, and have broad development prospects. They are usually extracted by water, ethanol and acetone and isolated and purified by macroporous resin and gel column chromatography. The packings commonly adopted for the column chromatography mainly included Sephadex LH-20, Diaion HP-20, MCI-gel CHP-20 and Toyopearl HW-40. Modern analytical techniques such as nuclear magnetic resonance spectroscopy(NMR), fast atom bombardment mass spectrometry(FAB-MS) and circular dichroism(CD) are generally used for the structural identification of tannins. Howe-ver, their isolation, purification and structural identification are still challenging. It is necessary to use a variety of high-throughput screening methods to explore their pharmacological activities and to explore the material basis responsible for their functions through experiments in vivo.

Metabolic mechanism of Prunella vulgaris in treatment of ethanol-induced oxidative stress in rats based on metabonomics / 中国中药杂志

Prunella vulgaris(PV) is an edible and traditional medicinal herb which has a wide range application in fighting inflammation and oxidative stress, and protecting liver. Now it has been used to treat various types of liver diseases and has significant clinical efficacy. This study aims to investigate the effects of PV on ethanol-induced oxidative stress injury in rats and its metabolic mechanism. The rats were divided into control group, model group, PV group, and VC group. The liver protection of PV was identified by measuring pharmacological indexes such as antioxidant and anti-inflammatory activity. The metabolic mechanism of long-term ethanol exposure and the metabolic regulation mechanism of PV treatment were studied by LS-MS metabonomics. The pharmacological investigation indicated that ethanol could significantly decrease the contents of SOD, GSH-Px, CAT and other antioxidant enzymes in liver and increase the content of MDA. At the same time, PV could significantly reduce the contents of inflammatory factors(TNF-α, IL-6 and IL-1β) and liver function markers(ALT, AST, ALP) in serum. What's more, long-term ethanol exposure could significantly cause liver injury, while PV could protect liver. Metabolomics based on multiple statistical analyses showed that long-term ethanol exposure could cause significant metabolic disorder, and fatty acids, phospholipids, carnitines and sterols were the main biomarkers. Meanwhile, pathway analysis and enrichment analysis showed that the β oxidation of branched fatty acids was the main influencing pathway. Also, PV could improve metabolic disorder of liver injury induced by ethanol, and amino acids, fatty acids, and phospholi-pids were the main biomarkers in PV treatment. Metabolic pathway analysis showed that PV mainly regulated metabolic disorder of ethanol-induced liver injury through phenylalanine, tyrosine and tryptophan biosynthetic pathways. This study could provide a new perspective on the hepatoprotective effect of natural medicines, such as PV.

The regulation role of PDK/Akt signaling pathway in berberine combined with ginsenoside Rg3 induced apoptosis of nasopharyngeal carcinoma cells / 中国药理学通报

Aim To study the effect of berberine combined with ginsenoside Rg3 on the apoptosis of nasopharyngeal carcinoma ( NPC ) cells, and to discuss the role of the PDK/Akt signaling pathway in this process. Methods Real time cellular analysis (RTCA)_fluorescence double-staining flow cytometry and Hoechst 33342 staining were used to detect the effects of ber¬ berine combined with ginsenoside Rg3 on the proliferation and apoptosis of NPC cells. Western blot was used to examine the effects of drugs on the expressions of apoptosis-related proteins and the key proteins of PI3K/Akt signaling pathway. Results Berberine combined with ginsenoside Rg3 inhibited the proliferation and induced cell apoptosis of NPC cells. Expressions of PI3K p 11 0 α and p-Akt were significantly down-regulated in combined drug group. After activation of PI3K/Akt signaling pathway, the effect of berberine combined with ginsenoside Rg3 on inhibiting CNE2 cell proliferation and inducing apoptosis was reduced. Compared with combination group, the levels of Survivin, PCNA and Bcl-2 were relatively enhanced, while the level of Bax declined (P < 0. 05). Conclusions Berberine combined with ginsenoside Rg3 may play a role in inhibiting the proliferation and inducing apoptosis of NPC cells through PI3K/Akt signaling pathway.

Molecular mechanism of vascular remodeling in hypertension and Chinese medicine intervention / 生理学报

Vascular remodeling is a significant pathological characteristic of hypertension, which is regulated by complex regulatory networks. The vascular remodeling may be adaptive initially, however it becomes maladaptive and decompensation eventually and further compromises target organ function, leading to hypertensive cardiovascular complications. This review focuses on the role and mechanisms of vascular remodeling in the pathogenesis and progression of hypertension and its complications. Moreover, the strategies of syndrome differentiation of traditional Chinese medicine application provide clinical and theoretical evidences for hypertensive vascular remodeling therapy. A better understanding of underlying signaling pathways, therapeutic targets in vascular remodeling, as well as screening of active ingredients from traditional Chinese medicine may be able to provide some effective approaches for vascular protection in hypertensive diseases.

Developing spectrum-toxicity relationship with rough set theory for hepatotoxicity material basis of Polygonum multiflorum / 中国中药杂志

Idiosyncratic hepatotoxicity of Polygonum multiflorum has attracted a great attention in the world. The most toxic part of idiosyncratic hepatotoxicity was screened by MTT assay and flow cytometry, which was the 50% ethanol elute by macroporous adsorptive resins from alcohol-extraction of P. multiflorum. The fingerprints were collected by HPLC from 50% ethanol elute of crude and processed P. multiflorum from different habitats, then 14 common peaks were determined. Spectrum-toxicity relationship was analyzed by rough set theory(RST). Two main chemical components were predicted for idiosyncratic hepatotoxicity, in which TSG was the greater contributor. Idiosyncratic hepatotoxicity of TSG was tested in vitro, and the results indicated that TSG was the most important constituent contributed to idiosyncratic hepatotoxicity of P. multiflorum. The study showed the discovery of the main chemical components for idiosyncratic hepatotoxicity, and RST was effective for analyzing the spectrum-toxicity relationship, which could be a new method used in the effective/toxic constituents field of traditional Chinese medicine.

Analyzing crude/processed root of Polygonum multiflorum from different habitats by UPLC fingerprint and mode identification methods / 中国中药杂志

To establish a content determination method for 2,3,5,4'-tetrahydroxy stilbene-2-O-β-D-glucoside (TSG) of the crude/processed root of Polygonum multiflorum from different habitats in China and set up the fingerprint by using UPLC. Various samples were pretreated by macro-porous resin. Then UPLC analysis was performed on Waters ACQUITY UPLC@BEH C18 chromatographic column (2.1 mm×50 mm, 1.7 μm) at (25±5) ℃. A binary gradient elution system was composed of acetonitrile (phase A) and 0.5% acetic acid solution (phase B). Detection was performed at the wavelength of 254 nm, and the mobile flow rate was set at 0.3 mL•min⁻¹. Results showed that the yield of extraction of the 2,3,5,4'-tetrahydroxy stilbene-2-O-β-D-glucoside from root of P. multiflorum was all over 25.0% after macro-porous resin separation; an exclusive UPLC fingerprint method of the crude/processed root of P. multiflorum from different habitats was successfully set up and 17 chromatographic peaks were calibrated. Cluster analysis can not entirely distinguish the crude one from the processed one, while principal component analysis absolutely can. 2,3,5,4'-tetrahydroxy stilbene-2-O-β-D-glucoside is the composition that has largest differences in variable importance in projection (VIP) between crude and processed root of P. multiflorum. The separating method can gain high-purity 2,3,5,4'-tetrahydroxy stilbene-2-O-β-D-glucoside, and the determination method is simple, sensitive, reliable and can be used in fast identifying the crude/processed root of P. multiflorum or as a method for overall quality control of root of P. multiflorum.

Effect of Autophagy Over Liver Diseases / 中国医学科学杂志(英文版)

In recent years, increasingly evidences show that autophagy plays an important role in the pathogenesis and development of liver diseases, and the relationship between them has increasingly become a focus of concern. Autophagy refers to the process through which the impaired organelles, misfolded protein, and intruding microorganisms is degraded by lysosomes to maintain stability inside cells. This article states the effect of autophagy on liver diseases (hepatic fibrosis, fatty liver, viral hepatitis, and liver cancer), which aims to provide a new direction for the treatment of liver diseases.

Analysis of different dosage forms of Xiasangju granules on fingerprints and models using high performance liquid chromatography / 中国中药杂志

To establish the fingerprints of Xiasangju granules (with sugar and non-sugar forms) by HPLC, and provide reference for their identification and effective quality control. High performance liquid chromatography (HPLC) method was used to collect the fingerprints of 20 batches of non-sugar Xiasangju granules and 34 batches of sugar type Xiasangju granules. Their main different components were classified and screened by mode identification methods (principal component analysis, PCA, and orthogonal partial least squares discriminate analysis, OPLS-DA). The principal components were identified by comparing with reference standards. The fingerprints of Xiasangju granules (sugar type and non-sugar type) were established. PCA could not fully classify the two types of granules, while OPLS-DA could obviously classify these two different types of Xiasangju granules. Six components showed greatest difference between two types of granules, including salviaflaside, luteoloside and linarin. The developed mode identification method is helpful to control the overall quality of Xiasangju granules, and it provides an effective approach to quality evaluation.

Crosstalk between Wnt5a and inflammatory signaling in inflammation / 生理学报

Wnt5a belongs to the large WNT family of cysteine-rich secreted glycoproteins, which is involved in multiple signaling pathways that regulate a variety of cellular processes, including cell motility, proliferation differentiation and so on during development. The regulation and signaling transduction of Wnt5a have been reported to closely relate to inflammatory response, which indicates that Wnt5a plays a critical role in the occurrence and development of inflammatory diseases. In this review, we summarized data on Wnt5a and its signaling pathway, as well as their involvement in inflammatory response. Further comprehensive understanding of the function and relationship between Wnt5a and inflammatory response would help us to develop novel diagnostic and therapeutic strategies for prevention and treatment of inflammatory diseases.

Research on biological detoxification of Chinese medicine containing aristolochic acid A by ten microorganisms / 中国中药杂志

This paper was aim to screen microorganisms with attenualed efficiency for Chinese medicine containing aristolochic acid A by liquid-state fermentation. Twelve Chinese medicine were detected by UPLC and aristolochic acid A was only founded in four species of Aristolochia, those were Caulis Aristolochiae Manshuriensis, Aristolochiae Radix, Aistolochia Contorta Bunge and Herba Aristolochiae Mollissima,but not in the others. With the four Chinese medicine containing aristolochic acid A as raw material, ten microorganisms were tested, and the content of aristolochic acid A was detected by UPLC. The results showed that one microorganism can decrease content of aristolochic acid A in all those four Chinese medicine.

Effects of SUMOylation on the subcellular localization and function of DAXX / 生理学报

Death domain-associated protein (DAXX) as a multifunctional nuclear protein widely resides in nucleolus, nucleoplasm, chromatin, promyelocytic leukaemia nuclear bodies (PML-NBs) and cytoplasm. It plays significant roles in transcriptional regulation, apoptosis, cell cycle and other biological activities. Small ubiquitin-like modifier (SUMO) is required for SUMOylation which is a highly conserved post-translational modification in a wide variety of cellular processes. Numerous studies demonstrated that SUMOylation has a great effect on the subcellular localization and functional regulation of DAXX. This review will provide a summary for SUMOylation of DAXX.

miRNA expression change of differentiation of mice marrow mesenchymal stem cells into adipocytes / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore miRNA expression change of differentiation of mice marrow mesenchymal stem cells (MSCs) into adipocytes, which lay the foundation for further studies on molecular mechanism of miRNA regulating the differentiation of MSCs into adipocytes.</p><p><b>METHODS</b>C57BL/6 mice MSCs were isolated, cultured through the whole bone marrow method, amplified by the differential adherent method. Cell growth was observed by morphology and the expression of superficial antigen CD29, CD44, CD34 were detected through immunohistochemistry. MSCs was induced to differentiation into adipocytes with adipocyte differentiation medium, and adipogenic differentiation of MSCs was analyzed by oil Red O staining. MicroRNA microarray was used to investigate the differentially expressed miRNAs in MSCs and adipocytes.</p><p><b>RESULTS</b>(1) The fifth passage of MSCs had high purity under an inverted m icroscope. Immunohistochemistry staining showed that CD29, CD44 were positive and CD34 was negative in more than 90% MSCs. There were a large number of lipid droplets in cytoplasm after MSCs were induced with adipocyte differentiation medium, Oil O staining was positive. (2) The microarray experiment showed that 75 differentially expressed miRNAs were obtained in adipocytes compared with MSCs, 20 up-regulated and 55 down-regulated miRNAs were observed among them.</p><p><b>CONCLUSION</b>There was a expression change of miRNA of differentiation of MSCs into adipocytes, some miRNAs might play important roles in MSCs adipogenic differentiation.</p>

Preparation and identification of monoclonal antibody against human thrombomodulin / 生理学报

To produce specific monoclonal antibody (McAb) against human thrombomodulin (hTM), the full-length hTM cDNA-expressing plasmid pThr402 was transfected into CHO cells by Lipofectamine 2000 reagent. The hTM-expressing CHO cells, which was confirmed by flow cytometry and Western blot, were obtained by G418 selection. Then the McAb against hTM was prepared with classic hybridoma technique. A cell line of CHO-TM5 with high level of hTM was used to immunize female Balb/c mice 3 times at an interval of 4 weeks. On the third day after the third immunization, mice were sacrificed and spleen cells were harvested to prepare hybridoma cells with SP2/0 cells at the ratio of 10 to 1. Hybridoma cells were then cultured at 96-well plates for screening. Cellular enzyme-linked immunoabsorbent assay (CELISA) was applied twice. The first CELISA was done with polythene ELISA plate with a monolayer of CHO-TM5 cells. The positive clones from the first screen were then selected by reacting with similar screening ELISA plate but with CHO cell monolayer instead. Only clones that were positive for the first screening and negative for the second screening were kept, and called as CHO-TM5(+)CHO(-) hybridoma cells. Balb/c mice were intraperitoneally injected with the selected hybridoma cells. Ascites were collected and monoclonal antibodies were purified using FPLC, and its Ig class, subclass, and titer were then determined respectively. The specificity of the yielded McAb was identified with CELISA, flow cytometry, ABC immunohistochemistry and immunoblotting. One line of hybridoma cells with high expression of specific McAb against hTM, NH-1, was obtained. The Ig subclass of the McAb was IgG1 and the titer of ascitic McAb was 1x10(-6). Flow cytometry, CELISA and Western blot assays demonstrated that McAb NH-1 could specifically recognize hTM expressed in CHO-TM5 cells and human umbilical vascular endothelial cells. Meanwhile, the tissue specificity of antigen recognized by McAb NH-1 was identified by immunohistochemical ABC staining. NH-1 can specifically recognize the natural hTM expressed mainly in vascular endothelial cells, which will potentially be useful for investigation of the functions and clinic values of hTM.

Effect of pravastatin on cholesteryl esters in foam cells and the relation with caveolin-1 / 生理学报

The purpose of the present study was to investigate the effect of pravastatin on cholesteryl esters in foam cells of murine macrophages and the relation with caveolin-1. RAW 264.7 murine macrophages were coincubated with 80 mg/L oxidized low density lipoprotein (ox-LDL) and pravastatin (0~100 mumol/L) respectively for 24 h. When the best control concentration of pravastatin was confirmed, RAW 264.7 murine macrophages were coincubated with 80 mg/L ox-LDL and pravastatin of the best concentration respectively for 0, 6, 12, 24 h. Oil red O dyeing experiment was used to show the lipid droplets in foam cells. High performance liquid chromatography (HPLC) analysis was performed to determine the content of cellular cholesterol. The level of caveolin-1 was determined by Western blot analysis. The result showed that when macrophages were incubated with 80 mg/L ox-LDL, the ratio of cellular cholesteryl ester to total cholesterol (CE/TC) was beyond 50% through HPLC analysis, and a great deal of lipid droplets displayed in cells through Oil red O dyeing experiment, which manifested the formation of the foam cells. Pravastatin could decrease CE in foam cells in a concentration-dependent manner (1~100 mumol/L). At the concentration of 100 mumol/L, pravastatin decreased cellular CE more than 50%. The effects of pravastatin on the decrease of CE in murine macrophages also displayed a time-dependent manner (incubated with 100 mumol/L pravastatin from 6 to 24 h). Moreover, the expression of caveolin-1 was decreased when the macrophages were incubated with ox-LDL (80 mg/L), while treatment with pravastatin increased the level of caveolin-1 and displayed a concentration- and time-dependent manner. These results suggest that pravastatin could inhibit the development of foam cells through the decrease of cellular CE, which may be related to the upregulation of caveolin-1.

Phytoestrogen genistein supplementation increases eNOS and decreases caveolin-1 expression in ovariectomized rat hearts / 生理学报

This study examined whether genistein influences the production of nitric oxide (NO) and expression of endothelial nitric oxide synthase (eNOS) and the modulators of eNOS activity in ovariectomized (OVX) rat hearts. Female mature Sprague-Dawley rats were subjected to bilateral ovariectomy, OVX rats were randomly divided into four groups: 17beta-estradiol (0.1 mg/kg, s.c. daily) was used as the positive control; low dose of genistein (0.5 mg/kg, s.c. daily); high dose of genistein (5.0 mg/kg, s.c. daily) and model. Sham operations as controls, the treatment lasted 6 weeks. Blood pressure, heart rate, plasma estradiol, heart and uterine weights were measured. Nitrite production in the myocardium was determined by nitrate reductase method. Protein level of eNOS, caveolin-1 and calmodulin was determined by Western blot. The results showed that nitrite production and eNOS protein in homogenized ventricular tissue was attenuated by approximately 53% and 67% in OVX rats compared with those in sham rats, respectively. Genistein increased nitrite production in rat heart in a dose-dependent manner, genistein at the dose of 5 mg/kg.d(-1) resumed nitrite production to a level similar to that in sham operated rats. Administration of genistein also increased eNOS protein expression in OVX rats myocardium with a concomitant decrease in the expression of caveolin-1, an endogenous eNOS inhibitory protein. Another eNOS stimulatory protein, calmodulin, was unchanged in these treatments. These effects were also observed in rats treated with 17beta-estradiol. Genistein at the dose of 5.0 mg/kg.d(-1) augmented uterine weight but this side effect in reproductive system was less than that of 17beta-estradiol. These results suggest that genistein supplementation and estrogen replacement therapy directly increase eNOS functional activity and NO production in the hearts of the OVX rats, but genistein has less side effects on the reproductive system than 17beta-estradiol.

Cyclosporin A inhibits the adhesion of neutrophil with ECV-304 induced by hypoxia/reoxygenation via ROS-Cyclophilin A-ERK1/2 pathway / 生理学报

To investigate the inhibition of cyclosporin A (CsA) on neutrophil adhesion to human umbilical vein endothelial cells (HUVECs, ECV-304) induced by hypoxia/reoxygenation and further explore its mechanism, a 1 h hypoxia/4 h reoxygenation model was reproduced using ECV-304. The adhesion rate of neutrophils to ECV-304 was determined by measuring the activity of endogenous hexosaminidase. The expression of endothelial cell adhesion molecules of E-selectin and ICAM-1 was measured by flow cytometry. The expression of cyclophilin A (CyPA) and the activation of ERK1/2 was compared among experimental groups by Western blot. The content of reactive oxygen species (ROS) was measured by Fenton reaction. After being stimulated with 1 h hypoxia/4 h reoxygenation, ECV-304 showed an enhanced neutrophil adhensiveness in association with an increased surface expression of E-selectin and ICAM-1. In parallel, the content of ROS was also increased. These effects were significantly suppressed by the addition of CsA. Most importantly, the expression of CyPA was significantly increased following 1 h hypoxia/4 h reoxygenation, which was accompanied with an increased activation of ERK1/2. Treatment with CyPA inhibitor CsA and CyPA antisense oligonucleotides significantly inhibited the activation of ERK1/2 and decreased the adhesion of neutrophils to ECV-304. The specific ERK1/2 inhibitor PD98059 caused an inhibition of neutrophil adhesion to hypoxia/reoxygenation-stimulated ECV-304. Our data confirm that CsA inhibits neutrophil adhesion to hypoxia/reoxygenation stimulated ECV-304 by a mechanism involving inhibition of the signal transduction of ROS, CyPA and ERK1/2.

Effect of 3' exonuclease activity of polymerase on extension of phosphorothioate-modified primers / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To determine whether 3'phosphorothioate-modified-2 terminal mismatched primers can turn off DNA polymerization mediated by Exo(+) polymerase.</p><p><b>METHODS</b>Two-directional primer extension was performed using polymerase with and without 3' exonuclease activity. The effects of unmodified primers and 3' phosphorothioate-modified primers on primer extension were evaluated.</p><p><b>RESULTS</b>Exo(-) polymerase yielded products from matched and mismatched primers regardless of their modification. However, 3' phosphorothioate-modified primers with a single base mismatch at -2 position worked similarly to the terminal (-1) mismatched primers in triggering the novelly reported "off-switch" of Exo(+) polymerase.</p><p><b>CONCLUSION</b>These data suggested that the "off-switch" can be of enormous application in the diagnosis of single gene diseases and in the association studies by single nucleotide polymorphism screening.</p>

Research progress of protein kinase C-zeta / 中国药理学通报

Protein Kinase C-zeta (PKC-ζ) is a new member of protein kinase C family and has some specific characteristics as comparing with the classical PKC. It lacks the C2 domain making its kinase activity Ca2+ -independent, and it possesses only one zinc-finger region in its regulatory domain. Therefore, PKC-ζ does not bind Ca2+ and can not be activated by diacylglycerol or phorbol esters. In addition, many researches showed that PKC-ζ could induce differentiation, mediate insulin-stimulation protein synthesis, activate immunity of human neutrophils, inhibit proliferation of cancer cells and regulate the function of actin cytoskeleton. What is more, PKC-ζ plays an important role in signal transduction of cells, such as mediating MAPK and NF-κB activation.