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Biomedical subjects

H Ye

Publications and source records attributed to H Ye.

At least 37 records · Page 2Linked to original sources
PubMed2001

Organ distribution of gene expression after intravenous infusion of targeted and untargeted lentiviral vectors.

Lentiviral vectors represent an attractive technology platform from which to develop a targetable injectable gene delivery system for transduction of specific cell populations in vivo, irrespective of their cell cycle status. Targeted HIV-1-based lentiviral vectors were generated by pseudotyping them with chimeric murine leukemia virus (MLV) envelope glycoproteins displaying N-terminal targeting polypeptides. Vectors displaying an EGF polypeptide were fully infectious on EGF receptor-negative cells, but were inactive on cells with abundant EGF receptors (inverse targeting). Receptor-mediated inactivation of gene transfer was overcome by competing the EGF receptors on the target cells with soluble EGF or by removing the displayed EGF domain from the surface of the vector particles by factor Xa cleavage of a specific protease substrate engineered into its tethering linker (protease targeting). Intravenous infusion of nontargeted HIV-1 vectors led to maximal luciferase activity in liver and spleen with moderate or minimal activity in heart, skeletal muscle, lung, brain, kidney, ovaries and bone marrow. In contrast, intravenous EGF-displaying vectors were expressed maximally in spleen with very low level luciferase expression detectable in liver (EGF-receptor rich). Liver transduction by the EGF-displaying vector was restored by pretreating the animals with soluble EGF suggesting that these vectors are inversely targeted to spleen.

Animals↗
PubMed2001

Internal ribosome entry site regulates translation of Kaposi's sarcoma-associated herpesvirus FLICE inhibitory protein.

The gammaherpesvirus Kaposi's sarcoma-associated herpesvirus (KSHV) (or human herpesvirus 8) is associated with the endothelial tumor Kaposi's sarcoma (KS) and lymphoproliferative disorders in immunocompromised individuals. Only a small number of viral proteins are expressed in B cells latently infected with KSHV; here we characterize the mechanism of expression of one of these, the viral FLICE inhibitory protein v-FLIP (K13, ORF71). The v-FLIP coding region is present in a bicistronic message, following the v-cyclin coding region. Using both in vitro translation and cell transfection assays, we have identified an internal ribosome entry site (IRES) preceding the v-FLIP start codon and overlapping the v-cyclin (ORF 72) coding region, which allows v-FLIP translation. Using an antibody against v-FLIP we have detected expression of the endogenous protein in latently infected KSHV-positive primary effusion lymphoma (PEL) cell lines. Induction of apoptosis by serum withdrawal from PEL cells results in a relative increase in v-FLIP synthesis, as previously described for some cellular proteins translated from IRES.

5' Untranslated Regions↗
PubMed2001

Quantitative study of the infection in brain neurons in human rabies.

Rabies virus is a highly neuronotropic virus that causes encephalomyelitis. Rabies virus infection was studied in neurons in the brain of an 8-year-old girl that died of rabies in Mexico. The extent of the neuronal infection was evaluated quantitatively in neuronal cell types of the brain using histologic staining for Negri bodies and immunoperoxidase staining for rabies virus antigen in the same neurons. Quantitative image analysis was used to compare the amount of infection in five different neuronal cell types, which was expressed as a percentage of neuronal area. Purkinje cells and periaqueductal gray neurons showed the largest percentage area for both Negri bodies and signal for rabies virus antigen. In general, there was a good linear relationship between the area of Negri bodies and the area of signal for rabies virus antigen. Many neurons with rabies virus antigen did not have Negri bodies, however, and some neurons with large antigen signals, especially Purkinje cells and periaqueductal gray neurons, lacked Negri bodies. Formation of Negri bodies is likely influenced by factors that vary in different neuronal cell types.

Brain↗
PubMed2001

[A prospective, randomized controlled study comparing the effects of gonadotropin-releasing hormone agonist long and short protocols for in vitro fertilization].

OBJECTIVE: To compare the effects of gonadotropin-releasing hormone agonist (GnRH-a) long and short protocols as part of in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatment. METHODS: One hundred and nine infertile couples accepted a prospective, randomized comparative study for IVF or ICSI treatment were divided into GnRH-a long protocol group (55 cases) and GnRH-a short protocol group (54 cases). GnRH-a long protocol group: GnRH-a was taken by nasal spray 0.9 mg/day starting on day 21 of the previous menstrual cycle. Once the patient was down regulated, gonadotropin (Gn) injection was started. GnRH-a short protocol group: GnRH-a was taken by nasal spray 0.45 mg/day starting on day 2 of the menstrual cycle, and Gn was started on the same day. Two groups had human chorionic gonadotrophin (hCG) administered when the leading follicle was at least 18 mm in diameter. Oocytes were retrieved 36 hours after hCG administration guided by transvaginal ultrasounography. IVF/ICSI were performed as routine. RESULTS: Serum follicle stimulating hormone and luteinizing hormone (LH) levels on the day of starting Gn were lower in the long protocol group comparing with the short protocol group [(4.4 +/- 1.2) IU/L Vs (6.3 +/- 1.7) IU/L, (2.7 +/- 1.5) IU/L Vs (4.4 +/- 2.8) IU/L, P < 0.01 respectively]. The levels of serum estradiol (E2), LH and E2 per oocyte on the day of hCG injection were lower in the long protocol group comparing with the short protocol group [(7,119 +/- 3,584) pmol/L Vs (9,523 +/- 3,587) pmol/L, (1.0 +/- 1.0) IU/L Vs (4.0 +/- 3.4) IU/L, (610 +/- 315) pmol/L Vs (935 +/- 450) pmol/L, P < 0.01 respectively]. Patients treated with short protocol were stimulated for a shorter period, required fewer Gn ampoules than the long protocol group [(10.1 +/- 1.5) d Vs (11.1 +/- 1.2) d, (23.4 +/- 8.7) Amps Vs (28.0 +/- 8.6) Amps, P < 0.01 respectly]. There are no statistically differences between the two groups in the numbers of oocytes retrieved, metaphase of second meiosis oocytes, fertilized oocytes, cleaved embryos, high quality embryos and pregnancy rates. CONCLUSIONS: The GnRH-a long and short protocols have equal effects on controlled ovarian hyperstimulation for in vitro fertilization. Patients who received GnRH-a short protocol required fewer ampoules of gonadotrpins and shorter period of treatment than those who received the GnRH-a long protocol.

Adult↗
PubMed2001

[The influence of antidepressive therapy on short-term prognosis in elderly patients with unstable angina and depression].

OBJECTIVE: To observe the influence of antidepressive therapy on short-term prognosis in elderly unstable angina pectoris patients with depression. METHODS: 76 unstable angina pectoris patients were random into a therapy group (38) and control group (38). Patients in the therapy group were treated with psychotherapy and administration of antidepressant Fluoxetine (Prozac Eli Lilly, USA) 20mg once a day on the basis of regular cardiac medicine therapy for 12 weeks, Patients in the control group were only treated with regular cardiac medicine therapy. RESULTS: Myocardial ischaemia in the therapy group was significantly improved. The recurrence rate of angina pectoris and incidence ratio of acute myocardial infarction in the therapy group were low. There was significant difference in comparison with the control group (P < 0.05). CONCLUSION: Antidepression can significantly improve the short-term prognosis in elderly unstable angina pectoris patients.

Aged↗
PubMed2000

MODY associated with two novel hepatocyte nuclear factor-1alpha loss-of-function mutations (P112L and Q466X).

Maturity-onset diabetes of the young (MODY) is an autosomal dominant form of diabetes characterized by early onset of pancreatic dysfunction. MODY type 3 is caused by mutations in the hepatocyte nuclear factor (HNF)-1alpha. During a screening of Norwegian patients with suspected MODY we identified two novel HNF-1alpha mutations, P112L and Q466X. The molecular mechanisms underlying the disease were studied by analyzing the DNA binding properties, transcriptional activation, and subcellular localization of HNF-1alpha P112L and Q466X compared to wild type HNF-1alpha. P112L had reduced ability to bind an HNF1 consensus sequence and to activate transcription. Q466X did not differ from wild type HNF-1alpha in DNA binding activity. Transactivation, however, was markedly reduced. When both mutants were coexpressed with wild type HNF-1alpha in HeLa cells, transcriptional activity appeared unaffected, suggesting that a dominant-negative mechanism was not present. Immunolocalization experiments showed that P112L HNF-1alpha was correctly targeted to nuclei in HeLa cells. In contrast, some Q466X HNF-1alpha protein was retained in the cytoplasm, which indicated that the mechanism for nuclear localization was disturbed. Thus, the HNF-1alpha mutations P112L and Q466X both seem to impair pancreatic beta-cell function by loss-of-function mechanisms; P112L by reduced DNA binding and reduced ability to transactivate, and Q466X by reduced transactivation and incomplete nuclear targeting.

DNA↗
PubMed2000

Thermodynamic characterization of the interaction between TRAF2 and tumor necrosis factor receptor peptides by isothermal titration calorimetry.

The tumor necrosis factor receptor (TNFR) superfamily can induce diverse biological effects, including cell survival, proliferation, differentiation, and apoptosis. The major signal transducers for TNFRs are the family of TNF receptor associated factors (TRAFs). The direct interaction between TRAFs and the intracellular tails of TNFRs is the first step of this signal relay process. Structural studies have revealed a trimeric nature of TRAF2 and a symmetrical mode of receptor binding, suggesting the involvement of trivalent TNFR2-receptor interaction in the signal transduction. In this study, using isothermal titration calorimetry (ITC), we report thermodynamic characterization of the interaction between TRAF2 and monomeric peptide sequences from TNFR members, including TNFR2, CD40, CD30, Ox40, and 4-1BB, and the Epstein-Barr virus (EBV)-transforming protein, latent infection membrane protein-1 (LMP1). The dissociation constants of the interaction were shown to range between 40 microM and 1.9 mM, which are substantially weaker than most protein-peptide interactions. The interaction is entirely driven by exothermic enthalpy, consistent with the abundance of polar contacts. The enthalpy of the interaction has a significant temperature dependence (DeltaCp = -245 cal/mol small middle dotK). The unfavorable entropy in the interaction and the comparison with structural energetics calculations suggest the involvement of conformational rearrangement in the interaction. The low affinity of TRAF2 to monomeric receptor peptides further supports the importance of avidity contribution in TRAF2 recruitment by these receptors upon ligand-induced trimerization or higher order oligomerization.

Amino Acid Sequence↗
PubMed2000

Expression of a chimeric farnesyl diphosphate synthase gene in Artemisia annua L. transgenic plants via Agrobacterium tumefaciens-mediated transformation.

An Agrobacterium tumefaciens-mediated transformation system was developed for Artemisia annua L. Using this system a cDNA encoding farnesyl diphosphate synthase (FDS placed under a CaMV 35S promoter) was transferred into A. annua via A. tumefaciens strain LB4404. Leaf or leaf discs were used as explants to be infected with A. tumefaciens and an optimal concentration of 20 mg/l kanamycin was applied to select kanamycin resistant shoots. Forty-five lines of resistance kanamycin shoots transformed with FDS were established. Analysis of PCR showed that at least 20 shoots transformed with the FDS gene were PCR positive. Southern blot analysis suggested the foreign FDS gene had been integrated into the A. annua genome, and Northern blot analysis revealed that the foreign FDS gene expressed at the transcriptional level in five shoot lines (F-1, F-4, F-61, F-62 and F-73 shoot lines). Analysis of artemisinin demonstrated that about 8 approximately 10 mg/g DW of artemisinin were then detected in transgenic plants regenerated from five shoot lines, this is about 2-3 times higher than that in the control.

Journal Article↗
PubMed2000

A novel mechanism of TRAF signaling revealed by structural and functional analyses of the TRADD-TRAF2 interaction.

TRAF proteins are major mediators for the cell activation, cell survival, and antiapoptotic functions of the TNF receptor superfamily. They can be recruited to activated TNF receptors either by direct interactions with the receptors or indirectly via the adaptor protein TRADD. We now report the structure of the TRADD-TRAF2 complex, which is highly distinct from receptor-TRAF2 interactions. This interaction is significantly stronger and we show by an in vivo signaling assay that TRAF2 signaling is more readily initiated by TRADD than by direct receptor-TRAF2 interactions. TRADD is specific for TRAF1 and TRAF2, which ensures the recruitment of clAPs for the direct inhibition of caspase activation in the signaling complex. The stronger affinity and unique specificity of the TRADD-TRAF2 interaction are crucial for the suppression of apoptosis and provide a mechanistic basis for the perturbation of TRAF recruitment in sensitizing cell death induction.

Amino Acid Sequence↗
PubMed2000

BCL10 gene mutation in lymphoma.

BCL10 is directly involved in t(1;14)(p22;q32) of mucosa-associated lymphoid tissue (MALT) lymphoma. Wild-type BCL10 promoted apoptosis and suppressed malignant transformation in vitro, whereas truncated mutants lost the pro-apoptotic activity and exhibited gain of function enhancement of transformation. We studied 220 lymphomas for genomic BCL10 mutation by polymerase chain reaction-single-strand conformational polymorphism and DNA sequencing. Nineteen mutations were found in 13 lymphoma specimens, as follows: 8 of 120 (6.7%) mucosa-associated lymphoid tissue (MALT) lymphomas, 4 of 42 (9.5%) follicular lymphomas, and 1 of 23 (4.3%) diffuse large B-cell lymphomas. No mutations were found in 14 mantle cell lymphomas or 21 T-cell lymphomas. High-grade MALT lymphoma tended to show a slightly higher mutation frequency (2 of 25, 8%) than low-grade MALT tumor (6 of 95, 6.3%). Among low-grade gastric MALT lymphoma, mutations were found in 3 of 11 tumors that did not respond to Helicobacter pylori eradication therapy, but none were found in 22 tumors that regressed completely after H pylori eradication. All 14 potentially pathogenic mutations were distributed in the carboxyl terminal domain of BCL10. Deletion accounted for 10 of these mutations; 10 of 14 mutations caused truncated forms of BCL10. Western blot analysis of a mutant case confirmed the presence of truncated BCL10 products of anticipated size. Our results suggest that BCL10 mutation may play a pathogenic role in B-cell lymphoma development, particularly in aggressive and antibiotic unresponsive MALT lymphomas, and may further implicate the biologic importance of the carboxyl terminal of the molecule. (Blood. 2000;95:3885-3890)

Adaptor Proteins, Signal Transducing↗
PubMed2000

[Effect of homocysteine on the proliferation and differentiation of rat embryo midbrain cell].

In order to determine the potential mechanisms by which HCY may exerts its teratogenic effects, a micromass culture for rat embryo midbrain cell was used to reveal the differentiation and proliferation of the cell under different HCY doses (0-10 mmol/L). The results showed that with increased concentration of HCY, the promotion effect changed into inhibition. The concentration inhibiting the formation of differentiated foci by 50% of the control was 4.3 mmol/L, and 2.3 mmol/L when S9 was added. It had an inhibition effects on proliferation in the testing scope. The result suggested that HCY obviously inhibited more cell differentiation than proliferation. The teratogenic hazard of HCY may play an important role in the occurrence of neural tube defects.

Animals↗
PubMed2000

Stimulation of adipose differentiation related protein (ADRP) expression in adipocyte precursors by long-chain fatty acids.

Adipose differentiation related protein (ADRP) is a 50-kDa protein expressed in adipocytes and transcriptionally activated when adipocyte precursors differentiate into mature adipocytes. Recent experiments have demonstrated that ADRP is a fatty acid binding protein that specifically facilitates the uptake of long-chain fatty acids. The present investigation provides evidence that ADRP mRNA and protein expression in preadipocytes is stimulated by fatty acids in a time- and dose-dependent fashion. ADRP mRNA expression was maximally stimulated at fatty acid concentrations of or above 10(-5) M. Stimulation of ADRP expression was observed with the nonmetabolizable fatty acid 2-bromopalmitate and with natural fatty acids. Stimulation of ADRP mRNA expression by fatty acids peaked between 5 and 8 hr and decreased by 24 hr. Stimulation of ADRP expression by fatty acids was completely inhibited by treatment with actinomycin D, suggesting that fatty acid stimulates ADRP gene expression at the transcriptional level. Comparison of the effect of several fatty acids with varying carbon chain lengths indicated that long-chain fatty acids were active in stimulating ADRP, whereas short-chain fatty acids such as caproate and 2-bromooctanoate had no effect. The degree of saturation of fatty acids did not influence their ability to stimulate ADRP expression. These studies provide new information on the regulation of ADRP and identify a new target regulated by fatty acids during adipose differentiation.

Adipocytes↗
PubMed2000

BCL10 expression in normal and neoplastic lymphoid tissue. Nuclear localization in MALT lymphoma.

BCL10 is an apoptotic regulatory molecule identified through its direct involvement in t(1;14)(p22;q32) of mucosa-associated lymphoid tissue (MALT) lymphoma. We examined BCL10 protein expression in various normal tissues and B-cell lymphomas by immunohistochemistry of formalin-fixed and paraffin-embedded tissues using mouse BCL10 monoclonal antibodies. BCL10 protein was expressed in lymphoid tissue but not in 21 various other tissues with the exception of breast. In normal B-cell follicles, the protein was expressed abundantly in the germinal center B cells, moderately in the marginal zone, but only weakly in the mantle zone B cells. Irrespective of their stage of B-cell maturation, BCL10 was predominantly expressed in the cytoplasm. In contrast, each of the four MALT lymphomas with t(1;14)(p22;q32) showed strong BCL10 expression in both the nucleus and cytoplasm. Twenty of 36 (55%) MALT lymphomas lacking the translocation exhibited BCL10 expression in both the nucleus and cytoplasm although at a much lower level, whereas the remaining 16 cases displayed only cytoplasmic BCL10. Unlike MALT lymphoma, both follicular and mantle cell lymphomas generally displayed BCL10 expression compatible to their normal cell counterparts. Our results show differential expression of BCL10 protein among various B-cell populations of the B-cell follicle, indicating its importance in B-cell maturation. The subcellular localization of BCL10 was frequently altered in MALT lymphoma in comparison with its normal cell counterparts, suggesting that ectopic BCL10 expression may be important in the development of this type of tumor.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Spatially and functionally distinct roles of the PI3-K effector pathway during NGF signaling in sympathetic neurons.

NGF is a target-derived growth factor for developing sympathetic neurons. Here, we show that application of NGF exclusively to distal axons of sympathetic neurons leads to an increase in PI3-K signaling in both distal axons and cell bodies. In addition, there is a more critical dependence on PI3-K for survival of neurons supported by NGF acting exclusively on distal axons as compared to neurons supported by NGF acting directly on cell bodies. Interestingly, PI3-K signaling within both cell bodies and distal axons contributes to survival of neurons. The requirement for PI3-K signaling in distal axons for survival may be explained by the finding that inhibition of PI3-K in the distal axons attenuates retrograde signaling. Therefore, a single TrkA effector, PI3-K, has multiple roles within spatially distinct cellular locales during retrograde NGF signaling.

Animals↗
PubMed2000

Facile solid-phase construction of indole derivatives based on a traceless, activating sulfonyl linker

[reaction: see text] Palladium-mediated coupling/intramolecular indole cyclization of terminal alkynes with resin 8, followed by cleavage of the sulfonamide linkage, were executed under mild conditions to provide diverse indoles 10 in excellent yield and purity. This chemistry benefits from a dual-activation process that derives from use of a traceless N-sulfonyl linker. Also, direct mercuration of 9 (X = H, R = 4-Me-C6H4), followed by palladium-mediated coupling with methyl acrylate, efficiently provided 3-functionalized product 12.

Journal Article↗
PubMed2000

Distribution of ion transport mRNAs throughout murine nose and lung.

Evidence of absorptive or secretory ion transport in different respiratory regions of the mouse was sought by assessing the regional distribution of alpha-, beta-, and gamma-epithelial sodium channel (ENaC; Na(+) absorptive), cystic fibrosis transmembrane conductor regulator (CFTR), and Na(+)-K(+)-2Cl(-) cotransporter mRNAs. High levels of ENaC subunit expression were found in nasal surface epithelium and gland ducts. CFTR was expressed in both superficial nasal respiratory epithelium and glands. These results are consistent with basal amiloride-sensitive Na(+) absorption and cAMP-dependent Cl(-) secretion in murine nasal epithelia. Expression of all three ENaC subunits increased progressively from trachea to terminal bronchioles. Intermediate levels of CFTR and cotransporter expression in bronchial epithelium diminished in bronchioles. The low abundance of CFTR mRNA throughout murine pulmonary epithelium is consistent with functional data that attributes Cl(-) secretion predominantly to an alternative Cl(-) channel. alpha-ENaC as the only mRNA found in all regions of airway epithelia is consistent with the alpha-subunit as requisite for Na(+) absorption, and the increased expression of alpha-, beta-, and gamma-ENaC in distal airways suggests a greater absorptive capability in this region.

Animals↗