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Yang Lu

Publications and source records attributed to Yang Lu.

At least 91 records · Page 5Linked to original sources

[Studying dystrophin gene deletion in the northeast of China and applicating].

To detect the distribution characteristics of dystrophin gene deletions of the DMD/BMD patients in the northeast of China and apply for prenatal gene diagnosis, we have analyzed the distribution of the breakpoints of the deleted-patients and the optimized primer-assembly after screening deletions of 120 DMD/BMD patients via multiplex PCR with 12-pair primers and male high-risk fetuses have been detected deletion by multiplex PCR. Results indicated the deletion frequency was 49.2%, about 66.4% deletion breakpoints positioned in introns 44-52, intron 50 was the highest breakpoint (14.8%). The optimized four-primer-assembly was the primers of exon 48, 51, 45 and 8, which could detect 41.7% deletions of all cases; 9 deletions male ones of 29 high-risk fetuses were detected, who had the same deletion-segments as their probands. For the first time screening deletions of DMD/BMD patients in the northeast of China, we have found distribution of the deletions mainly lied in two hot-spots, neighboring regions of exon 8 might be a real deletion 'hot spot' in this area compared with other areas of our country; introns 44-52 of dystrophin gene were highly unstable and prone to break: intron 44 was more stable than the whole molecular region of 'central deletion hot spot' and the unstability of intron 50 changed along with the regional and ethnic difference; the optimized primer-assembly provided the short-cut for detecting patients and making prenatal gene diagnosis, especially it's feasible and advantageous for the isolated pedigrees.

Adolescent↗

Dibothrioclinin I and II, epimers from Gerbera piloselloides (L.) Cass.

Dibothrioclinin I and II, namely (+)-(11R,12S,25R,27S)- and (+/-)-(11RS,12RS,25RS,27SR)-3,3,7,17,21-pentamethyl-4,12,18,26-tetraoxaheptacyclo[15.11.1.0(2,15).0(5,14).0(6,11).0(19,28).0(20,25)]nonacosa-5(14),6,8,10,19(28),20,22,24-octaene-13,27-dione, respectively, are C(30)H(28)O(6) epimers which are derived from two bothrioclinin moieties joined so as to create an additional six-membered ring. Structurally, the epimers differ only by inversion at one C atom of a central ring junction and the corresponding six-membered rings have similar conformations in each molecule, except for one ring adjacent to this inversion site.

Asteraceae↗

Molecular profile of the unique species of traditional Chinese medicine, Chinese seahorse (Hippocampus kuda Bleeker).

A cDNA library of male Chinese seahorse (Hippocampus kuda Bleeker) was constructed to investigate the molecular profile of seahorse as one of the most famous traditional Chinese medicine materials, and to reveal immunological and physiological mechanisms of seahorse as one of the most primitive vertebrates at molecular level. A total of 3372 expressed sequence tags (ESTs) consisting of 1911 unique genes (345 clusters and 1566 singletons) were examined in the present study. Identification of the genes related to immune system, paternal brooding and physiological regulation provides not only valuable insights into the molecular mechanism of immune system in teleost fish but also plausible explanations for pharmacological activities of Chinese seahorse. Furthermore, the occurrence of high prevalent C-type lectins suggested that a lectin-complement pathway might exert a more dominant function in the innate immune system of teleost than mammal. Carbohydrate recognition domain (CRD) without a collagen-like region in the lectins of seahorse was likely an ancient characteristic of lectins similar to invertebrates.

Amino Acid Sequence↗

Differentiating effects of anisodamine on cognitive amelioration and peripheral muscarinic side effects induced by pilocarpine in mice.

Based on the cholinergic hypothesis of Alzheimer's disease (AD), many cholinomimetics have been tested for the treatment of AD. Although some of them have beneficial effects, peripheral muscarinic side effects limit their utility. Our present experiments showed that muscarinic agonist pilocarpine (pilo) could significantly improve memory deficits induced by scopolamine in step-through task, but be accompanied by pronounced peripheral cholinergic side effects such as hypersalivation, bradycardia, diarrhea and so on. Anisodamine (aniso) is a peripheral muscarinic blocker isolated from a Chinese herb Anisodus tanguticus and is widely used in China. When combined with aniso, pilo preserved its central efficacy with very minor peripheral side effects. Cholinomimetics combined with peripheral muscarinic blockers may provide alternative therapeutic strategies for AD.

Animals↗

HIV-1 p55Gag encoded in the lysosome-associated membrane protein-1 as a DNA plasmid vaccine chimera is highly expressed, traffics to the major histocompatibility class II compartment, and elicits enhanced immune responses.

Several genetic vaccines encoding antigen chimeras containing the lysosome-associated membrane protein (LAMP) translocon, transmembrane, and cytoplasmic domain sequences have elicited strong mouse antigen-specific immune responses. The increased immune response is attributed to trafficking of the antigen chimera to the major histocompatibility class II (MHC II) compartment where LAMP is colocalized with MHC II. In this report, we describe a new form of an HIV-1 p55gag DNA vaccine, with the gag sequence incorporated into the complete LAMP cDNA sequence. Gag encoded with the translocon, transmembrane and cytoplasmic lysosomal membrane targeting sequences of LAMP, without the luminal domain, was poorly expressed, did not traffic to lysosomes or MHC II compartments of transfected cells, and elicited a limited immune response from DNA immunized mice. In contrast, addition of the LAMP luminal domain sequence to the construct resulted in a high level of expression of the LAMP/Gag protein chimera in transfected cells that was further increased by including the inverted terminal repeat sequences of the adeno-associated virus to the plasmid vector. This LAMP/Gag chimera with the complete LAMP protein colocalized with endogenous MHC II of transfected cells and elicited strong cellular and humoral immune responses of immunized mice as compared with the response to DNA-encoding native Gag, with a 10-fold increase in CD4+ responses, a 4- to 5-fold increase in CD8+ T-cell responses, and antibody titers of >100,000. These results reveal novel roles of the LAMP luminal domain as a determinant of Gag protein expression, lysosomal trafficking, and possibly of the immune response to Gag.

3T3 Cells↗

HER2/PI-3K/Akt activation leads to a multidrug resistance in human breast adenocarcinoma cells.

Growth factor receptor-mediated signal transduction has been implicated in conferring resistance to conventional chemotherapy on cancer cells. In this study, we delineated a pathway that involves HER2/PI-3K/Akt in mediating multidrug resistance in human breast cancer cells. We found that the cell lines that express both HER2 and HER3 appear to have a higher phosphorylation level of Akt (activated Akt). Transfection of HER2 in MCF7 breast cancer cells that express HER3 caused a phosphoinoside-3 kinase (PI-3K)-dependent activation of Akt, and was associated with an increased resistance of the cells to multiple chemotherapeutic agents (paclitaxel, doxorubicin, 5-fluorouracil, etoposide, and camptothecin). Selective inhibition of PI-3K or Akt activity with their respective dominant-negative expression vectors sensitized the cells to the induction of apoptosis by the chemotherapeutic agents. We further demonstrated that MCF7 cells expressing a constitutively active Akt, in which the phospholipid-interactive PH domain of Akt was replaced by a farnesylation sequence for constitutive membrane anchorage (DeltaPH-Akt1-farn), showed a similar increased resistance to the chemotherapeutic agents. Our results suggest that activation of Akt1 by HER2/PI-3K plays an important role in conferring a broad-spectrum chemoresistance on breast cancer cells and that Akt may therefore be a novel molecular target for therapies that would improve the outcome of patients with breast cancer.

Adenocarcinoma↗

Dengue 2 PreM-E/LAMP chimera targeted to the MHC class II compartment elicits long-lasting neutralizing antibodies.

A dengue 2 plasmid DNA vaccine (pD2) expressing the pre-membrane and envelope proteins (preM-E) was modified by replacing the dengue transmembrane and cytoplasmic sequences with those of the mouse lysosome-associated membrane protein (pD2/LAMP). Immunofluorescence and confocal microscopy of human 293, NIH 3T3, and macrophage IC21 cell lines transfected with pD2/LAMP showed that the preM-E/LAMP protein chimera was present in vesicles containing endogenous LAMP and major histocompatability complex class II (MHC II), in contrast to the non-vesicular localization of native preM-E protein lacking the LAMP targeting sequence. Mice immunized with pD2 showed an antigen-specific immunoglobulin response but the neutralizing antibodies titers (plaque reduction neutralization test, PRNT(50)) elicited by the native protein were minimal. In contrast, vaccination with pD2/LAMP resulted in PRNT(50) of 270, 320 and 160 at approximately 1, 3 and 8 months after two immunizations with 50 microg DNA, and approached 100% neutralization at 1:20 dilution. Additional immunization with pD2/LAMP, after 8 months, increased the neutralizing antibody titers to >640. Comparable neutralizing antibody responses were induced by two vector backbones, pVR1012 and pVax-1, at 5 and 50 microg of DNA. The neutralizing responses to the pD2/LAMP chimera were greatly superior to those elicited by pD2 in all conditions. These results underscore the importance of MHC class II presentation of DNA-encoded dengue-virus envelope protein for production of neutralizing antibodies.

Animals↗

Micrandilactone A: a novel triterpene from Schisandra micrantha.

[structure: see text] A novel nortriterpene, micrandilactone A, was isolated from the medicinal plant Schisandra micrantha. This is the first example of an unusual, natural, highly oxidized cycloartane skeleton with a biosynthetically modified eight-membered ring D isolated from the family Schisandraceae.

Lactones↗

EST analysis of gene expression in the tentacle of Cyanea capillata.

Jellyfish, Cyanea capillata, has an important position in head patterning and ion channel evolution, in addition to containing a rich source of toxins. In the present study, 2153 expressed sequence tags (ESTs) from the tentacle cDNA library of C. capillata were analyzed. The initial ESTs consisted of 198 clusters and 818 singletons, which revealed approximately 1016 unique genes in the data set. Among these sequences, we identified several genes related to head and foot patterning, voltage-dependent anion channel gene and genes related to biological activities of venom. Five kinds of proteinase inhibitor genes were found in jellyfish for the first time, and some of them were highly expressed with unknown functions.

Amino Acid Sequence↗

5alpha-steroidal glycosides from Parepigynum funingense.

Four new 5alpha-steroidal glycosides with an unusual framework, funingenosides A (1), B (2), C (3), and D (4), were isolated from the roots of Parepigynum funingense. Their structures were elucidated on the basis of 1D and 2D NMR techniques. The structure and relative stereochemistry of compound 1 were demonstrated by X-ray crystallographic analysis.

Apocynaceae↗

Cytotoxic constituents of Isodon rubescens var. lushiensis.

Five new ent-kaurane diterpenoids, ludongnins F-J (1-5), along with 10 known compounds, guidongnins A-C (6-8), angustifolin (9), 6-epiangustifolin (10), sculponeatin J (11), gardenin D, 5,3',4'-trihydroxy-6,7,8-trimethoxyflavone, pedalitin, and quercetin, were isolated from the leaves of Isodon rubescens var. lushiensis. The structures of 1-5 were determined by spectroscopic analysis, as well as X-ray crystallographic analysis of 1. Compounds 1-11 were evaluated against K562 leukemia cells for their cytotoxic effects.

Antineoplastic Agents, Phytogenic↗

Fomlactones A-C, novel triterpene sactones from Fomes cajanderi.

Investigation of the neutral ether extracts of the fungus Fomes cajanderi led to the isolation of three novel ketal lactones named fomlactones A (1), B (2), and C (3). These compounds were identified by analysis of IR, HRMS, CD, and 1D and 2D NMR data. The structure of fomlactone C (3) was confirmed by X-ray diffraction analysis.

Basidiomycota↗

Sensitization of breast cancer cells to radiation by trastuzumab.

HER2, a member of the human epidermal growth factor (EGF) receptor family, not only plays important roles in the progression of breast cancer tumorigenesis and metastasis, but may protect cancer cells from conventional cytotoxic therapies as well. In the current study, we evaluated the effect of targeting HER2 on radiosensitization of human breast cancer cells. Using six breast cancer cell lines with various levels of HER2 (BT474, SKBR3, MDA453, MCF7, ZR75B, and MDA468), we found that trastuzumab (Herceptin), a humanized monoclonal antibody that may inhibit breast cancer cell proliferation but does not induce apoptosis when used alone, enhanced radiation-induced apoptosis of the cells in a HER2 level-dependent manner. We furthered this study in MCF7 cells transfected for high levels of HER2 (MCF7HER2). Compared with parental or control vector-transfected MCF7 cells, MCF7HER2 cells showed increased phosphorylation of at least two important HER2 downstream molecules, protein kinase B/Akt and mitogen-activated protein kinase (MAPK), and increased resistance to radiotherapy, as shown by reduced induction of apoptosis and increased cell clonogenic survival after radiation. Exposure of the cells to trastuzumab down-regulated the levels of HER2 and reduced phosphorylation levels of Akt and MAPK in MCF7HER2 cells, and sensitized these cells to radiotherapy. When specific inhibitors of the phosphatidylinositol 3-kinase (PI3-K) and MAPK kinase (MEK) pathways were used, we found that exposure of MCF7HER2 cells to the PI3-K inhibitor LY294002 inhibited Akt phosphorylation and radiosensitized the cells, whereas the radiosensitization effect by the MEK inhibitor PD98059 was relatively weaker, albeit the phosphorylation of MAPK was reduced by PD98059 treatment. Our results indicate that the PI3-K pathway might be the major pathway for trastuzumab-mediated radiosensitization of breast cancer cells.

Antibodies, Monoclonal↗

[Study on selective isolation of volatile oil in the seed of Fructus foeniculi].

OBJECTIVE: To study the selective isolation of a single chemical component from volatile oil of Fructus foeniculi by inclucion method. METHOD: The host molecule was selected and a single chemical component isolated from volatile oil by the host-guest recognition. RESULT: X-ray single crystal analysis showed that 1,1,6,6-tetraphenylhexa-2, 4-diyne-1, 6-diol could successfully include 4-[1-propenyl] benzaldehyde from volatile oil of Fructus foeniculi. CONCLUSION: The host-guest inclusion technology can be used to isolate a single component selectively from mixture.

Crystallization↗

EST analysis of mRNAs expressed in neurula of Chinese amphioxus.

Amphioxus, a cephalochordate, is the closest living relative to the vertebrates. In order to investigate the molecular mechanisms of the early embryogenesis of amphioxus, we constructed a neurula embryo cDNA library of Chinese amphioxus (Branchiostoma belcheri tsingtauense) and generated 5235 expressed sequenced tags in the present study. The initial ESTs consisted of 638 clusters and 1855 singletons, which revealed approximately 2493 unique genes in the data set. Of these sequences, 35.52% ESTs matched to known genes, 12.76% matched to other ESTs, and 51.71% had no match to any known sequences in GenBank. Interestingly we found homologous genes related to neural development and human disease. Bioinformatic analysis showed the direct evidence that the gene homologue found only in vertebrates in previous studies also exists in the amphioxus genome. This study provides a preliminary view of the gene information involved in the development of neurula embryos of Chinese amphioxus and helps our understanding of vertebrate evolution at gene level.

Animals↗

A novel single amino acid deletion caspase-8 mutant in cancer cells that lost proapoptotic activity.

Caspase-8 is an important initiation caspase that activates the caspase cascade during death receptor-mediated apoptosis. We here report a novel caspase-8 mutant with a naturally occurring deletion of leucine 62 (Delta Leu62casp-8). Delta Leu62casp-8 has a shorter half-life than its wild-type counterpart. Unlike wild-type caspase-8, Delta Leu62casp-8 failed to interact with wild-type caspase-8 or with the adaptor protein FADD. Delta Leu62casp-8 lost its proapoptotic activity in mammalian cells. The leucine 62 therefore is critical for caspase-8 function, and the mutation may be one of the mechanisms through which some types of cancer cells escape from programmed cell death.

Amino Acids↗

Interleukin-1 beta is involved in the pressor response of amygdaloid neurons excited by sodium glutamate.

The effects of interleukin-1beta in the paraventricular nucleus or caudal arcuate nucleus on hypertensive and tachycardiac responses induced by excitation of the central amygdaloid nucleus were studied. We observed that microinjection of sodium glutamate into central amygdaloid nucleus resulted in hypertension and tachycardia. Microinjection of interleukin-1beta into paraventricular nucleus or caudal arcuate nucleus induced significant pressor and tachycardiac responses while pretreatment with microinjection of rabbit anti-rat interleukin-1beta antibody into bilateral paraventricular nuclei or arcuate nuclei attenuated the hypertensive response induced by microinjection of 40 nmol sodium glutamate into central amygdaloid nucleus. The above results suggest that the pressor effect of central amygdaloid nucleus is mediated by interleukin-1beta in paraventricular nucleus or arcuate nucleus.

Amygdala↗