Biomedical subjects

Wei Su

Publications and source records attributed to Wei Su.

28 records · Page 2Linked to original sources

PubMed2005

Molecular cloning and characterization of rat LC3A and LC3B--two novel markers of autophagosome.

Rat microtubule-associated protein light chain 3 (LC3) is a homologue of yeast Atg8, an essential component of autophagy. Following synthesis, the C-terminus of rat LC3 is cleaved by a cysteine protease-Atg4, to produce LC3-I, which is located in cytosolic fraction. LC3-I can be converted to LC3-II through the processing by Atg7 (E1-like enzyme) and Atg3 (E2-like enzyme). LC3-II is modified by phosphatidylethanolamine on C-terminus and binds tightly to autophagosomal membrane. Here we reported the cloning of two novel variants of rat LC3, named LC3A and LC3B, respectively, and LC3B is an alternative splicing variant of LC3. LC3A, LC3B, and LC3 showed different expression patterns in rat tissues, suggesting a functional divergence among these proteins. When LC3A and LC3B were overexpressed, both exhibited two forms (18 and 16 kDa, representing types of I and II, separately), which might be due to post-translational modification including the characteristic C-terminal cleavage at these two proteins as similar to that found in rat LC3 and yeast Atg8. Subcellular localization demonstrated that both LC3A and LC3B are colocalized with LC3 and associated with the autophagic membranes. Mutation analysis further revealed that the conserved Gly120 residues of LC3A and LC3B are essential for their characteristic C-terminal cleavage and localization to autophagic membranes. Present data suggested that LC3A and LC3B could also be used as two novel autophagosomal markers.

Alternative Splicing↗

PubMed2005

Thin-film transistors based on Langmuir-Blodgett films of heteroleptic bis(phthalocyaninato) rare earth complexes.

An ordered molecular assembly of heteroleptic bis(phthalocyaninato) rare earth complexes M(Pc)[Pc(OC8H17)8] [M = Tb, Lu; H2Pc = phthalocyanine; H2Pc(OC8H17)8 = 2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyanine] has been fabricated by the Langmuir-Blodgett (LB) technique and characterized by surface pressure-area isotherms, electronic absorption and polarized electronic absorption spectroscopy, low-angle X-ray diffraction, and atomic force microscopy. The molecular ordering in the LB multilayer film on SiO2 substrate was made into a p-channel field effect transistor (FET), which was generally operated in the enhanced mode. The energy levels of the highest occupied molecular orbital and the lowest unoccupied molecular orbital as well as the energy band diagram can be deduced from the electrochemical measurement results. The charge mobilities of Tb(Pc)[Pc(OC8H17)8] and Lu(Pc)[Pc(OC8H17)8] were calculated to be about 6.4 x 10(-4) and 1.7 x 10(-3) cm2 V(-1) s(-1), respectively.

Journal Article↗

PubMed2005

Cloning and characterization of OsORC2, a new member of rice origin recognition complex.

In eukaryotic cells, the origin recognition complex (ORC) governs the initiation site of DNA replication and formation of the prereplication complex. The isolation, characterization and tissue-specific expression of a putative ORC subunit 2 (OsORC2) in Oryza sativa is described here. A novel cDNA fragment encoding rice ORC2 was isolated by screening the subtractive library, which had a higher expression level in inflorescence meristem than in shoot apical meristem. The full-length cDNA of rice ORC2 was obtained by the method of rapid amplification of cDNA ends, which contained an 1140 bp open reading frame encoding a 379 amino acid polypeptide. Sequence alignment shows that there is a high homology between the deduced amino sequence of OsORC2 and maize ORC2 (85%). The tissue-specific expression pattern of OsORC2 reveals that it is abundant in roots, seedling and inflorescence meristem, while its expression level is much lower in mature leaves and shoot.

Amino Acid Sequence↗

PubMed2005

CPU 86017, p-chlorobenzyltetrahydroberberine chloride, attenuates monocrotaline-induced pulmonary hypertension by suppressing endothelin pathway.

AIM: To elucidate the involvement of the endothelin (ET) pathway in the pathogenesis of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) and the therapeutic effect of CPU 86017 (p-chlorobenzyltetrahydroberberine chloride) in rats. METHODS: Rats were injected with a single dose (60 mg/kg, sc) of MCT and given CPU 86017 (20, 40, and 80 mg/kg-1/d-1, po) or saline for 28 d. The hemodynamics, mRNA expression, and vascular activity were evaluated. RESULTS: Right ventricular systolic pressure and central venous pressures were elevated markedly in the PAH model and decreased by CPU 86017. In the PAH group, the endothelin-1 (ET-1) in serum and lungs was dramatically increased by 54% (79.9 pg/mL, P<0.01) and 93% (166.2 pg/mL, P<0.01), and mRNA levels of preproET-1, eNOS, and iNOS also increased dramatically compared with control. Compared with PAH group, CPU 86017 decreased the content of ET-1 to the normal level in lung tissue, but was less effective in serum. The level of NO was significantly increased in CPU 86017 at 80 and 40 mg/kg-1/d-1 groups in tissue, whereas the difference in serum was not significant. A significant reduction in MDA production and an increase in the SOD activity in the serum and lungs was observed in all three CPU 86017 groups. CPU 86017 80 mg/kg-1/d-1 po increased the activity of cNOS by 33% (P<0.01). The up-regulation of eNOS and iNOS mRNA levels induced by MCT was significantly reversed in 3 CPU 86017 groups, and preproET-1 mRNA abundance was also reduced notably in CPU 86017 80 mg/kg-1/d-1 group vs the PAH group. The KCl-induced vasoconstrictions in the calcium-free medium decreased markedly in PAH group but recovered partially after CPU 86017 intervention. The constrictions in the presence of Ca(2+) was not improved by CPU 86017. The phenylephrine-induced vasoconstrictions in the calcium-free medium decreased markedly in PAH group but not recovered after CPU 86017 intervention. The constrictions in the presence of Ca(2+) completely returned to the normal after CPU 86017 intervention. CONCLUSION: CPU 86017 suppressed MCT-induced PAH mainly through an indirect suppression of the ET-1 system, which was involved in the pathogenesis of the disease.

Animals↗

PubMed2004

A novel three-dimensional supramolecular coordination polymer: poly[[diaquadicadmium(II)-di-mu2-4,4'-bipyridyl-di-mu2-2-sulfonatobenzoato] dihydrate].

The hydrothermal reaction of Cd(CH3COO)2.2H2O, 4,4'-bipyridyl and 2-sulfobenzoic acid produced the title compound, {[Cd2(C7H4O5S)2(C10H8N2)2(H2O)2].2H2O}n, which forms a two-dimensional coordination polymer, the sheets of which are linked via hydrogen bonds. Two different types of Cd atoms are present, one lying on a twofold rotation axis and the other on a centre of inversion. Similarly, there are two types of bipyridyl ligand present, one lying across a twofold rotation axis and the other across a centre of inversion.

Journal Article↗

PubMed2003

Conspecific odor investigation by gray short-tailed opossums (Monodelphis domestica).

Gray short-tailed opossums (Monodelphis domestica) are small marsupials, which have recently become the subjects of numerous laboratory investigations. While these opossums have well-developed olfactory systems and complex scent-marking behaviors, the significance of their use of odors in conspecific communication is still poorly understood. Investigation of body odors by male and female opossums was examined in the present study. Males investigated flank and urine odors of nonestrous adult females significantly more than controls, but not urine from sexually inexperienced juvenile females or urine of females at cytological estrus. Since in this species females have an induced estrus, it would be advantageous for males to investigate and follow the odors of urine of diestrous females, which become receptive in proximity to males. Female opossums investigated odors of male mandibles and suprasternal glands significantly more than controls but not odors of male urine. We suggest that the use of glandular secretions is more common and more effective than urine for intraspecific communication between gray short-tailed opossums: In the semiarid conditions inhabited by the opossums, glandular secretions are less volatile and are effective for longer periods than urine and would be of greater value in intraspecific communication if, as suggested in the literature, these opossums are nomadic and meet one another infrequently.

Analysis of Variance↗

PubMed2002

Novel chondroitin sulfate-binding cationic liposomes loaded with cisplatin efficiently suppress the local growth and liver metastasis of tumor cells in vivo.

An increased level of chondroitin sulfate (CS) expression on the cell surface is often associated with malignant transformation and the progression of tumor cells. In this study, CSs expressed on highly metastatic tumor cells were used as a target for the selective delivery of anticancer drugs by polyethylene glycol (PEG)-coated liposomes that contained a new cationic lipid 3,5-dipentadecycloxybenzamidine hydrochloride (TRX-20). We found that PEG-coated TRX-20 liposomes (TRX-20 liposomes) bound preferentially to certain CSs, such as CS B, CS D, and CS E, whereas PEG-coated liposomes lacking TRX-20 showed no significant binding to any of the glycosaminoglycans tested. In vitro, TRX-20 liposomes, but not plain PEG liposomes, avidly bound to and were readily internalized by highly metastatic tumor cells such as LM8G5 and ACHN cells, which express large amounts of CS on the cell surface. When TRX-20 liposomes were loaded with cisplatin, they effectively killed the CS-expressing tumor cells in vitro, whereas cisplatin-PEG liposomes lacking TRX-20 were totally ineffective. When injected systemically, TRX-20 liposomes preferentially accumulated in the liver and in solid s.c. LM8G5 tumors. Therapeutic experiments in mice bearing a s.c. LM8G5 tumor revealed that cisplatin-loaded TRX-20 liposomes were significantly more effective in reducing the local tumor growth than cisplatin-loaded plain PEG liposomes or free cisplatin. Furthermore, the cisplatin-loaded TRX-20 liposomes markedly suppressed metastatic spreading of LM8G5 tumor cells to the liver, significantly increasing the survival time of the tumor-bearing mice. These results demonstrate that the CS-targeted delivery of anticancer drugs by novel cationic liposomes represents a potentially useful strategy to prevent the local growth and metastasis, particularly to the liver, of tumor cells that have enhanced expression of CS.

Animals↗

PubMed2002

Antitumor effect to IL-12 administration into the portal vein on murine liver metastasis.

BACKGROUND/PURPOSE: Interleukin (IL)-12 has been shown to possess potent antitumor activity, and an antitumor effect of systemic IL-12 administration has been reported in liver metastasis models. METHODS: In this study, we examined the usefulness of local IL-12 administration into the portal system in the treatment of liver metastasis. First, we confirmed the antitumor effect of recombinant IL-12 (rIL-12) on MC-38 tumors in an intracutaneous model. In the murine liver metastasis model, 1 x 10(5) of MC-38 cells were injected into the portal vein on day 0, and the spleen was transpositioned subcutaneously for administration of rIL-12 continually into the portal system. From days 3 to 7, 0.1 micro g rIL-12 was administered intraperitoneally or intrasplenicly, while Hanks' Balanced Salf Solution (HBSS) was injected intrasplenicly in the control group. RESULTS: The liver weight in the rIL-12 intraperitoneal treatment group (1.88 +/- 0.37 g) and that in the rIL-12 intrasplenic treatment group (1.43 +/- 0.21 g) were significantly less than that in the HBSS group (2.86 +/- 0.74 g; P < 0.05). The numbers of metastatic nodules in the rIL-12 intraperitoneal treatment group (22.3 +/- 17.1) and in the rIL-12 intrasplenic treatment group (12.4 +/- 13.8) were significantly less than that in the HBSS group (137.1 +/- 44.9; P < 0.05). Complete regression of the tumor was observed in one of six mice in the rIL-12 intrasplenic treatment group. This antitumor effect of rIL-12 on MC-38 liver metastasis was not observed in interferon (IFN)-gamma knockout mice. Intraportal administration of IL-12-transduced fibroblasts, which were syngeneic to C57BL/6 mice, had an antitumor effect in the MC-38 liver metastasis model. CONCLUSIONS: These results suggested that the local administration of IL-12 into the portal system would be a useful strategy for the treatment of liver metastasis.

Adenocarcinoma↗

PubMed2002

[Application of meshed acellular dermis xenograft (pigskin) with scalp thin skin autograft in 15 patients].

OBJECTIVE: To present the clinical application of the meshed acellular dermis xenograft with scalp thin split-thickness skin autograft. METHODS: The meshed acellular dermis xenograft (pigskin) was placed on the granulation or defects after scar resection. Four or five days afterwards, scalp thin split-thickness skin was transplanted. A total of 15 patients with 25 wounds were treated using this technique. The survival rates and quality of the grafts were observed. RESULTS: The survival rate of the meshed acellular dermis xenograft was (96.40 +/- 2.60)% and the scalp thin split-thickness skin autograft was (97.44 +/- 3.50)%. All grafts showed normal skin-alike color and elastic and smooth texture. CONCLUSION: The combined use of meshed acellular dermis xenograft and scalp skin autograft demonstrated an ideal way for the repair of full-thickness skin burn or defects from scar resection. The scalp can provide thin skin graft repeatedly without influence of the hair.

Adolescent↗

PubMed2002

[Lung cancer risk associated with genetic polymorphism in myeloperoxidase (-463 G/A) in a Chinese population].

OBJECTIVE: To examine the relationship between susceptibility to lung cancer among Chinese and genetic polymorphism at nucleotide -463 (G/A) in myeloperoxidase (MPO), an enzyme found in lysosomes of phagocytes and involved in the formation of hydroxyl radicals and activation of various smoking-related carcinogens. METHODS: The association of this polymorphism with lung cancer in a hospital-based case-control study of 314 patients and 320 age- and sex-matched controls was tested. The MPO genotypes were determined by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). RESULTS: The allele frequency for MPO-463A was found to be 11.0% for controls, compared with 15.0% for patients. Multivariate analysis showed an increased risk for overall lung cancer in subjects having GG genotype (OR, 1.7; 95% CI, 1.2 - 2.5), however, the elevated risk was limited to squamous cell carcinoma (OR, 2.4; 95% CI, 1.4 - 3.9; n = 177) but not to adenocarcinoma (OR, 1.3; 95% CI, 0.8 - 2.1; n = 137). In addition, the risky effect of the GG genotype on squamous cell carcinoma of the lung was evident only in the smokers and those who smoked >/= 26 pack-years (OR, 20.5; 95% CI, 5.6 - 75.3) as compared with GA and AA genotypes (OR, 6.2; 95% CI, 1.7 - 22.5) but not in the nonsmokers or those who smoked < 26 pack-years. CONCLUSION: Our data support the hypothesis that -463A polymorphism in the MPO gene may reduce the susceptibility to lung cancer in the Chinese.

Asian People↗