Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A gene encoding a homologue of phospholipase A(2) was identified from the Clonorchis sinensis adult cDNA plasmid library. The deduced amino acid sequence including a signal peptide that has 28-46% identity with secretory phospholipase A(2), group III (group III sPLA(2)) of other species. It also has typical features of group III sPLA(2)s including 10 cysteines, the key residues of the Ca(2+) loop and catalytic site. The recombinant protein encoded by this gene expressed in Escherichia coli showed a product of about 34kDa in SDS-PAGE. Prediction of signal peptide and Western blot analysis indicated the group III secretory phospholipase A(2) of C. sinensis (CsGIIIsPLA(2)) was an excretory-secretory product (ES product). The enzyme activity of the recombinant protein was determined using phosphatidylcholine as substrates. The result revealed that the protein was a Ca(2+)-dependent PLA(2). Both MTT test and cell cycle analysis of LX-2 showed a higher percentage of cells are in proliferation phase. Semi-quantitative RT-PCR experiments demonstrated an up-regulated expression of collagen III in these cells after incubation with the recombinant protein. We also identified that the recombinant CsGIIIsPLA(2) could bind to some membrane proteins on LX-2 cells specifically by immunofluorescence, thus there might be receptors of CsGIIIsPLA(2) on the LX-2 cell membrane. Our results suggest that CsGIIIsPLA(2) might play an important role in the initiation and development of hepatic fibrosis caused by C. sinensis.
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PMID:Molecular characterization of a novel Clonorchis sinensis secretory phospholipase A(2) and investigation of its potential contribution to hepatic fibrosis. 1946 58

In this study, a tubular scaffold composed of polylactide fibers (outside layer) and silk fibroin-gelatin fibers (inner layer) was fabricated successfully by electrospinning. Morphological, biomechanical, and dissolvable properties of the composite scaffolds were examined, in particular, biocompatibility of the scaffolds were evaluated in vitro and in vivo by means of cell culture and subcutaneous implantation test. The PLA/SF-gelatin tubular scaffolds, with porosity of approximately 82 +/- 2%, possessed appropriate breaking strength (2.21 +/- 0.18 MPa), pliability (60.58 +/- 1.23%), and suture retention strength (4.58 +/- 0.62 N). The burst pressure strength of the composite scaffolds reached 1596 +/- 20 mmHg, which is much greater than that of the native vessels. The composite scaffolds could hardly dissolve in the water; the water-dissolved rate was only 0.3 +/- 0.1%. MTT assay and SEM observation indicated that both 3T3 mouse fibroblasts and human umbilical vein endothelial cells could adhere, spread, and proliferate well on the composite tubular scaffolds after culturing for 14 and 21 days, respectively. The subcutaneous implantation results showed that macrophages and lymphocytes were not observed, which indicated that the composite scaffolds could induce minor inflammatory reactions in vivo. The PLA/SF-gelatin tubular scaffolds are biocompatible, possess appropriate biomechanical properties, and provide a favorable environment that supports the growth of cells, which shows that the composite tube can be considered as an ideal candidate for tissue engineering blood vessel.
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PMID:Fabrication and properties of the electrospun polylactide/silk fibroin-gelatin composite tubular scaffold. 1972 59

The interactions of post-culture treatments reagents used for fixing, lysing and cell quantification on poly(lactide-co-glycolide) (PLGA) flat sheet membrane scaffolds are presented. Lysing with Alkaline buffer solution/Triton X-100/MilliQ water (ATM) and fixing with 10% Neutral Buffered Formalin (10% NBF) had no affect on membrane structure while fixing with 95% ethanol caused smoothing of the surface, shrinkage and a reduction in surface area of 55, 48 and 33, for 100:0, 75:25 and 50:50 (PLA:PGA), respectively. PicoGreen assay was selected for cell (560pZIPv.neo) quantification since the background noise would not affect readings for cell numbers over 3,000 cells/cm(2), while the background reading was too high for MTT and Methylene Blue (MB). MB at 0.5% (w/v) was, however, deemed suitable for visualising cell morphology on the membranes. Furthermore ATM buffer was suitable for the PicoGreen assay, which allows the same samples to be used for quantification of alkaline phosphatase activity.
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PMID:Post-culture treatment protocols for PLGA membrane scaffolds. 1982 Oct 75

In photodynamic therapy (PDT) a tumor-selective photosensitizer is administered and then activated by exposure to a light source of appropriate wavelength. Multidrug resistance (MDR) is largely caused by the drug efflux from the tumor cell by means of P-glycoprotein, resulting in reduced efficacy of the anticancer therapy. This study deals with photodynamic therapy with Photofrin (Ph) on colon cancer cell lines (doxorubicin-sensitive and -resistant). The cells were treated with 15 and 30 microg/mL Ph and then irradiated by a light dose of 3 or 6 J/cm(2) (632.8 nm). After irradiation the cells were incubated for 0, 3 or 18 h. Crucial factors of oxidative stress (thiobarbituric acid reactive substances [TBARS], protein damage, thiazolyl blue tetrazolium bromide [MTT] assay), changes in cytosolic superoxide dismutase (SOD1) activity after photodynamic reaction (PDR), and the intracellular accumulation of photosensitizers in the cells were examined. Moreover, the expressions of glutathione S-transferase (GST)-pi, a marker protein for photochemical toxicity, and secretory phospholipase A(2), a prognostic and diagnostic marker for colon cancers, were determined. After PDR, increases in SOD1 activity and the level of TBARS were observed in both cell lines. The level of protein-associated -SH groups decreased after PDR. Both cell lines demonstrated stronger GST-pi and PLA(2) expression after PDR, especially after 18 h of incubation. The increasing level of reactive oxygen species following the oxidation of sulfhydryl cell groups and lipid peroxidation influence the activity of many transporters and enzymes. The changes in SOD1 activity show that photodynamic action generates oxidative stress in treated cells. Our study presents that PDR caused oxidative alterations in both examined colon adenocarcinoma cell lines. However, the MDR cells reacted more slowly and all oxidative changes occurred in the delay.
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PMID:Oxidative alterations induced in vitro by the photodynamic reaction in doxorubicin-sensitive (LoVo) and -resistant (LoVoDX) colon adenocarcinoma cells. 2040 24

A hybrid porous collagen scaffold mechanically reinforced with surface-activated poly(lactic acid) (PLA) fiber was prepared. PLA fibers, 20 mum in diameter and 1 mm in length, were aminolyzed with hexanediamine to introduce free amino groups on the surfaces. After the amino groups were transferred to aldehyde groups by treatment with glutaraldehyde, different amounts (1.5, 3, 5 and 8 mg) of surface-activated PLA fibers were homogeneously mixed with 2 ml type-I collagen solution (pH 2.8, 0.6 wt%). This mixture solution was then freeze-dried and cross-linked to obtain collagen sponges with surface-activated PLA fiber. Scanning electron microscopy observation indicated that the collagen sponges had a highly interconnected porous structure with an average pore size of 170 mum, irrespective of PLA fiber incorporation. The dispersion of surface-activated PLA fibers was homogeneous in collagen sponge, in contrast to unactivated PLA fibers. The compression modulus test results showed that, compared with unactivated PLA fibers, the surface-activated PLA fibers enhanced the resistance of collagen sponge to compression more significantly. Cytotoxicity assay by MTT test showed no cytotoxicity of these collagen sponges. L929 mouse fibroblast cell-culture studies in vitro revealed that the number of L929 cells attached to the collagen sponge with surface-activated PLA fibers, both 6 h and 24 h after seeding, was higher than that in pure collagen sponge and sponge with unactivated PLA fibers. In addition, a better distribution of cells infiltrated in collagen sponge with surface-activated PLA fibers was observed by histological staining. These results indicated that the collagen sponge reinforced with surface-activated PLA fibers is a promising biocompatible scaffold for tissue engineering.
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PMID:Reinforcement of a porous collagen scaffold with surface-activated PLA fibers. 2048 96

Copolymers composed of PLA and PTAm were prepared by a macromonomer approach. The PLA bearing vinyl group at chain end was copolymerized with 2,2,6,6-tetrametylpiperidine-4-ylacrylamide. The resulted copolymers were oxidized by a peroxide to give PTAm-g-PLA. The structures of the copolymers were confirmed by NMR and FTIR spectroscopy. The comparison of (1)H NMR results and SQUID measurements demonstrated that the oxidation of the PTAm fragment proceeded almost to completion. An MTT assay, cell adhesion and spreading evaluation showed that the copolymers exhibited improved cytocompatibility as compared to the PTAm homopolymer due to the introduction of the biocompatible PLA moiety.
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PMID:Biodegradable and electroactive TEMPO-substituted acrylamide/lactide copolymers. 2057 71

The present study was conducted to evaluate the antioxidant and anti-inflammatory activities of Jungia paniculata (DC.) A. Gray (Asteraceae), used traditionally in Peru. The dry leaves were extracted with methanol, 50% methanol, and water. The anti-inflammatory activity of this plant was studied using in vitro (nitric oxide production in RAW 264.7 macrophages and sPLA(2) inhibition assay) and in vivo (carrageenan-induced paw edema in rats and TPA-induced ear edema in mice) model systems. The antioxidant activity of extracts was studied using three in vitro model systems (DPPH(*) radical-scavenging assay, ABTS(*+) assay, and superoxide radical-scavenging activity). The results have been correlated with total phenolics and total flavonoids contents. In the NO test of the extracts of Jungia paniculata, no significant cytotoxicities were observed at the concentrations determined by MTT assay. Only the MeOH50 extract of Jungia paniculata significantly inhibited PLA(2) enzyme activity (82.3 +/- 2.6%). At 3 h, the 50% methanol extract of Jungia paniculata at an oral dose of 500 mg/kg showed significant suppression of carrageenan-induced rat paw edema (36.36%). The same extract induced a 93.99% reduction in TPA-induced edema in topical administration. The extracts exhibited a high antioxidant activity and contained high total levels of polyphenols and flavonoids. There was a significant linear correlation between total phenolics and flavonoids contents and antioxidant activity in the three models used. In conclusion, Jungia paniculata possesses anti-inflammatory and antioxidant properties, which confirm the use of this plant in folk medicine as a topical anti-inflammatory herbal.
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PMID:Anti-inflammatory and antioxidant activities of Jungia paniculata. 2067 77

In order to prepare targeted drug carriers, previously a biotin group has been attached by our group to the end of Pluronic F87/poly(lactic acid) and Pluronic P85/poly(lactic acid) block co-polymers to obtain B-F87-PLA and B-P85-PLA, respectively. In this paper, the active targeting properties of B-F87-PLA and B-P85-PLA nanoparticles in vitro were investigated through a three-step biotin-avidin interaction by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) tests and fluorescence microscopy (FM). Two kinds of human ovarian cancer cells (OVCAR-3 and SKOV-3) and paclitaxel were chosen for the cytotoxicity tests. CA-125 antigen is over-expressed on OVCAR-3 cells but not on SKOV-3 cells. The loading and release behavior of paclitaxel loaded in B-Pluronic-PLA nanoparticles were also studied. Paclitaxel loaded in both B-F87-PLA and B-P85-PLA nanoparticles shows an initial rapid release followed by a slow release period. Compared with SKOV-3 cells, the cytotoxicity results implied that paclitaxel-loaded B-Pluronic-PLA nanoparticles were delivered more effectively to OVCAR-3 cells due to the specific interaction between the biotin groups on the surface of B-Pluronic-PLA nanoparticles and the avidin/biotinylated MAb X306/CA-125 antigen complexes on the surface of OVCAR-3 cells. The active targeting properties of B-F87-PLA nanoparticles were further confirmed by FM.
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PMID:Active targeting behaviors of biotinylated pluronic/poly(lactic acid) nanoparticles in vitro through three-step biotin-avidin interaction. 2069 57

Polycaprolactone (PCL), poly (lactic acid) (PLA) and hydroxyapatite (HA) are frequently used as materials for tissue engineering. In this study, PCL/PLA/HA nanofiber mats with different weight ratio were prepared using electrospinning. Their structure and morphology were studied by FTIR and FESEM. FTIR results demonstrated that the HA particles were successfully incorporated into the PCL/PLA nanofibers. The FESEM images showed that the surface of fibers became coarser with the introduction of HA nanoparticles into PCL/PLA system. Furthermore, the addition of HA led to the decreasing of fiber diameter. The average diameters of PCL/PLA/HA nanofiber were in the range of 300-600 nm, while that of PCL/PLA was 776 +/- 15.4 nm. The effect of nanofiber composition on the osteoblast-like MC3T3-E1 cell adhesion and proliferation were investigated as the preliminary biological evaluation of the scaffold. The MC3T3-E1 cell could be attached actively on all the scaffolds. The MTT assay revealed that PCL/PLA/HA scaffold shows significantly higher cell proliferation than PCL/PLA scaffolds. After 15 days of culture, mineral particles on the surface of the cells was appeared on PCL/PLA/HA nanofibers while normal cell spreading morphology on PCL/PLA nanofibers. These results manifested that electrospun PCL/PLA/HA scaffolds could enhance bone regeneration, showing their marvelous prospect as scaffolds for bone tissue engineering.
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PMID:Electrospun PCL/PLA/HA based nanofibers as scaffold for osteoblast-like cells. 2113 24

The aim of this research was to investigate the effect of cationic polypeptides mixed with chitosan (CS) on in vitro transfection efficiency and cytotoxicity in human cervical carcinoma cells (HeLa cells). The polypeptides/DNA complexes and ternary complexes (CS, polypeptides and DNA) at varying weight ratios were formulated and characterized by using gel electrophoresis. Their particle sizes and charge were evaluated. The effect of the type and molecular weight (MW) of polypeptides, the weight ratio, order of mixing, the pH and serum on transfection efficiency and cytotoxicity were evaluated in HeLa cells. Three types of polypeptides (poly-L-lysine; PLL, poly-L-arginine; PLA and poly-L-ornithine; PLO) were able to form complete complex with DNA at weight ratio above 0.1. The PLA MW >70 kDa showed the highest transfection efficiency. The order of mixing between CS, PLA and DNA affected the transfection efficiency. The highest transfection efficiency was observed in ternary complexes of PLA/DNA/CS (2:1:4) equal to PEI/DNA complex. For cytotoxicity studies, over 80% the average cell viabilities of the complexes were observed by MTT assay. This study suggests that the addition of CS to PLA/DNA is easy to prepare, safe and exhibits significantly improved DNA delivery potential in vitro.
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PMID:Chitosan enhances transfection efficiency of cationic polypeptides/DNA complexes. 2139 72


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