We have chemically synthesized NGR-LDP-PYM, a novel CD13/aminopeptidase (APN)-targeting and hydrolase-resistant conjugate by cross-linking of the antitumor antibiotic pingyangmycin (bleomycin A5 , PYM) to an engineered NGR motif-integrated apoprotein (NGR-LDP) with a noncleavable linker. This protein-drug conjugate not only basically retains the original properties of PYM but also can specifically deliver PYM to the CD13/APN-expressing tumor cells. Furthermore, the resulting conjugate exhibits more resistance to hydrolysis of recombinant human bleomycin hydrolase than parental PYM.
View Article and Find Full Text PDFThis study is to optimize the preparation process of fusion protein Fv-LDP which was expressed in the form of inclusion body and consisted of lidamycin apoprotein LDP and single-chain Fv antibody (scFv) directed against type IV collagenase. The preparation and the dissolution of inclusion body, the immobilized metal affinity chromatography of the target protein and the renaturization by stepwise dialysis were optimized by single-factor analysis or orthogonal design. In addition, the refolded fusion protein Fv-LDP was refined by Sephadex G-75 chromatography followed by fluorescence-activated cell sorter (FACS)-based saturation binding assay to measure its antigen-binding activity.
View Article and Find Full Text PDFLPS stimulation of macrophages production of IFN-beta plays a key role in innate immunity defending the microbial invasion. In this study, the effect of S632A3 promoting LPS-induced IFN-beta production and the underlying mechanism were investigated, mRNA level was measured by real-time PCR, cytokine production was determined by ELISA, GSK-3beta activity was investigated by kinase assay, protein phosphorylation and expression were evaluated by Western blotting. The results revealed that S632A3 significantly augmented IFN-beta production by LPS-stimulated macrophages.
View Article and Find Full Text PDFSalidroside (SAL) is one of main active components of Rhodiola rosea L. and possesses diverse pharmacological effects. However, the direct role of SAL in bone metabolism remains elusive.
View Article and Find Full Text PDFNa(+)/K(+)-ATPase targeted cancer therapy has attracted increasing interests of oncologists in lung cancer field. Although multiple anti-cancer mechanisms of cardiac glycosides as Na(+)/K(+)-ATPase inhibitors are revealed, the role of autophagy and related molecular signaling pathway for the class of compounds in human non-small cell lung cancer (NSCLC) cells has not been systematically examined. We herein investigated the anti-cancer effects of two representative cardiac glycosides, digoxin and ouabain, in A549 and H460 cell lines.
View Article and Find Full Text PDFAlthough salidroside and salidroside-like compounds are considered as most critical constitutes needed and responsible for multiple therapeutic benefits of Rhodiola rosea L., including anti-aging, direct demonstration regarding the role of salidroside in anti-aging process is still deficient. In this study, we selected the H(2)O(2)-induced premature senescence model in human fetal lung diploid fibroblasts to investigate the protection of salidroside against aging in vitro and associated molecular mechanisms.
View Article and Find Full Text PDFObjective: Lidamycin, an enediyne antibiotic, leads to apoptosis and mitotic cell death of human tumor cells at high and low concentrations. The reason why tumor cells have distinct responses to lidamycin remains elusive. This study was to elucidate if cellular prosurvival molecules are involved in these responses.
View Article and Find Full Text PDFThe mechanism of apoptosis induced by SIRT1 deacetylase inhibitors in both human breast cancer MCF-7 and MCF-7 doxorubicin-resistant cells was studied. MTT assay was used to detect growth-inhibitory effect on the cells. Protein expression was detected by Western blotting.
View Article and Find Full Text PDFObjective: To study whether Lycium barbarum glycopeptide 3 (LBGP3) affects T cell apoptosis in aged mice.
Methods: LBGP3 was purified with DEAE cellulose and Sephadex columns. Apoptotic "sub-G1 peak" was detected by flow cytometry and DNA ladder was resolved by agarose gel electrophoresis.
Although enediyne antibiotic lidamycin ( LDM) is a potent inducer of apoptosis, the underlying mechanisms of its apoptotic functions remain to be explored. Here, we aim to elucidate its possible mechanisms in mitochondria initiated apoptotic pathway involved in human BEL-7402 and MCF-7 cells. Cytochrome c released from mitchondria to cytosol fraction was detected by Western blotting.
View Article and Find Full Text PDFBiomed Environ Sci
December 2006
Objective: To investigate the role of D-galactose, especially in the structural and functional changes of the immune system in aging.
Methods: Serum levels of advanced glycation end-products (AGE) were determined by ELISA method. Ultra-structures of thymus and spleen were detected by transmission electron microscopy.
A new antibiotic, S632A3, was isolated from a cultured broth of Streptomyces hygroscopicus S632. It was purified by column chromatography on silica gel, Sephadex LH-20 and HPLC. Structural studies by analysis of 1H NMR and 13C NMR, MS, UV and IR spectra in comparison with those of S632A2 clarified that S632A3 is an isomer of 9-methylstreptimidone.
View Article and Find Full Text PDFWorld J Gastroenterol
April 2005
The insulin/insulin-like growth factor 1 (IGF-1) signaling pathway is evolutionary conserved in diverse species including C.elegans, saccharomyces cerevisiae, Drosophila melanogaster, rodents and humans, which is involved in many interrelated functions that are necessary for metabolism, growth and reproduction. Interestingly, more and more research has revealed that insulin/IGF-1 signaling pathway plays a pivotal role in the regulation of longevity.
View Article and Find Full Text PDFAim: Mitotic cell death has been focused on in tumor therapy. However, the precise mechanisms underlying it remain unclear. We have reported previously that enediyne antibiotic lidamycin induces mitotic cell death at low concentrations in human epithelial tumor cells.
View Article and Find Full Text PDFBiomed Environ Sci
March 2004
Objective: To investigate whether two kinds of in vitro prepared advanced glycation end products (AGEs), Glu-BSA and Gal-BSA, could change oxidation stress and anti-oxidation abilities in astrocytes, and thus might contribute to brain injury.
Methods: Changes of GSH, MDA, SOD, MAO-B, nitric oxide were measured after AGEs treatment.
Results: Both 0.
Objective: To explore the effect of Dogwood fruits on tonifying kidney-yang.
Method: The effect of the water extract of Dogwood fruits on rats model of kidney-yang deficiency with the hydrocortisone was observed.
Result: The water extract of Dogwood fruits could make normal the liver weight, and mitigate hepatocyte pathologic changes, increase the heptocellular levels of RNA and hepatin, and decrease the malondialdehyde (MDA) in rats model of kidney-yang deficiency.
Objective: To analyze the effects of aging or advanced glycation on gene expression in the cerebrum and spleen of female C57BL/6J mice.
Methods: The gene expression profile was determined by using cDNA expression arrays containing 588 cDNA.
Results: Aging and advanced glycation resulted in differential gene expression patterns of cerebrum and spleen compared with young mice.
Objective: To investigate the inhibiting effects and mechanism of achyranthes bidentata polysaccharide (ABP) and lycium barbarum polysaccharide (LBP) on nonenzyme glycation in D-galactose induced mouse aging model.
Methods: Serum AGE levels were determined by AGE-ELISA, MTT method was used to determine lymphocyte proliferation, IL-2 activity was determined by a bioassay method. Spontaneous motor activity was used to detect mouse's neuromuscular movement, latency of step-through method was used to examine learning and memory abilities of mouse, colormetric assay was used to determine hydroxyproline concentration in mouse skin, pyrogallol autoxidation method was used to determine superoxide dismutase (SOD) activity of erythrocytes.
Aim: To investigate the synergetic effect and the mechanism of antitumor action of the antibiotic lidamycin in combination with cisplatin in vitro.
Methods: Cytotoxicity of the drugs was measured by clonogenic assay. Chromatin condensation was observed by co-staining with fluorescent dyes, Hoechst 33342 and propidium iodide.
Background & Objective: Lidamycin, one of enediyne antitumor antibiotics, was isolated by our institute. It is the focus of intense due to its unique chemical structure and potent cytotoxicities to tumor cells in vivo and in vitro. In addition to cleavage of DNA, effect of lidamycin on apoptotic gene expressions and cytoskeleton may involve in its high activities.
View Article and Find Full Text PDFAim: To investigate whether two kinds of in vitro prepared advanced glycation end products (AGE), Glu-BSA and Gal-BSA, could induce proinflammatory mediators IL-1beta and TNF-alpha, as well as oxidative stress and nitric oxide (NO), in astrocytes, thus contributing to brain injury.
Methods: Radioimmunoassay and RT-PCR technique were used to detect two cytokines' level and existence of receptor for AGE (RAGE). DTNB reaction was used to measure reduced glutathione (GSH) level.
Aim: To further study the effect of enediyne antibiotic lidamycin (C1027) on genomic DNA in human hepatoma BEL-7402 cells.
Methods: The DNA patterns were detected by agarose gel electrophoresis. The gene damage was revealed by Southern hybridization.