ABSTRACT
Although the apoptosis of chondrocytes plays an important role in endochondral ossification, its mechanism has not been elucidated. In this study, we show that guanosine induces chondrocyte apoptosis based on the results of acridine orange/ ethidium bromide staining, caspase-3 activation, and sub-G1 fraction analysis. The potent inhibitory effect of dipyridamole, a nucleoside transporter blocker, indicates that extracellular guanosine must enter the chondrocytes to induce apoptosis. We found that guanosine promotes Fas-Fas ligand interaction which, in turn, leads to chondrocyte apoptosis. These findings indicate a novel mechanism for endochondral ossification via metabolic regulation.
Subject(s)
Rats , Animals , Tumor Necrosis Factors/metabolism , Signal Transduction/drug effects , Receptors, Tumor Necrosis Factor/metabolism , Rats, Sprague-Dawley , Nucleoside Transport Proteins/metabolism , Membrane Glycoproteins/metabolism , Guanosine/pharmacology , Fas Ligand Protein , Chondrocytes/drug effects , Apoptosis/drug effects , fas ReceptorABSTRACT
Currently 18 monoclonal antibodies were approved by FDA for inj ection into humans for therapeutic or diagnostic purpose. And 146 clinical trials are under way to evaluate the efficacy of monoclonal antibodies as anti-cancer agents, which comprise 9% of clinical trials in cancer therapy field. When considering a lot of disappointment and worries existed in this field during the past 15 years, this boom could be called as resurrection. Antibodies have several merits over small molecule drug. First of all it is easier and faster in development, as proper immunization of the target proteins usually raises good antibody response. The side effect s of antibodies are more likely to be checked out in immunohistomchemical staining of whole human tissues. Antibody has better pharmacokinetics, which means a longer half-life. And it is non-toxic as it is purely a natural drug. Vast array of methods was developed to get the recombinant antibodies to be used as drug. The mice with human immunoglobulin genes were generated. Fully human antibodies can be developed in fast and easy way from these mice through immunization. These mice could make even human monoclonal antibodies against any human antigen like albumin. The concept of combinatorial library was also actively adopted for this purpose. Specific antibodies can be screened out from phage, mRNA, ribosomal library displaying recombinant antibodies like single chain Fvs or Fabs. Then the coding genes of these specific antibodies are obtained from the selected protein-gene units, and used for industrial scale production. Both naive and immunized libraries are proved to be effective for this purpose. In post-map arena, antibodies are receiving another spotlight as molecular probes against numerous targets screened out from functional genomics or proteomics. Actually many of these antibodies used for this purpose are already human ones. Through alliance of these two actively growing research areas, antibody would play a central role in target discovery and drug development.
Subject(s)
Animals , Humans , Mice , Antibodies , Antibodies, Monoclonal , Antibody Formation , Bacteriophages , Clinical Coding , Genes, Immunoglobulin , Genomics , Half-Life , Immunization , Molecular Probes , Pharmacokinetics , Proteomics , RNA, Messenger , Single-Chain AntibodiesABSTRACT
Oxidized low density lipoprotein (LDL) seems to take a part in atherogenesis through direct interactions with macrophages, endothelial cells, and smooth muscle cells, and is thought to participate in renal glomerular injury. For the purpose of illustrating the role of oxidized LDL in the human diseases, monoclonal antibodies were developed and characterized, recognizing oxidized LDL-specific epitopes that do not exist on native LDL. LDL was oxidized by the incubation with CuSO4, and used as immunogen. Splenocytes from the immunized mouse and mouse myeloma cells were fused to produce hybridomas, which were screened for the secretion of oxidized LDL-specific antibodies. Immunoblot analysis and binding affinity assay showed that these monoclonal antibodies recognize malondialdehyde-conjugated peptide epitopes.
Subject(s)
Humans , Antibodies, Monoclonal , Antibody Affinity , Antibody Specificity , Enzyme-Linked Immunosorbent Assay , Epitopes , Lipoproteins, LDL/immunology , Malondialdehyde/immunology , Malondialdehyde/analysis , Peptide Fragments/immunology , Thiobarbituric Acid Reactive Substances/analysisABSTRACT
No abstract available.
ABSTRACT
The histogenesis and differentiation of sweat gland tumors are controversial. Twenty-two cases of sweat gland tumors were stained by immunoperoxidase technique (ABC method) for the presence of S-100 protein, CEA, and two kinds of keratin. Four syringomas, 4 eccrine poromas, 2 eccrine porocarcinomas, 2 eccrine spiradenomas, 1 papillary eccrine adenoma, 3 clear cell hidradenomas, 3 mixed tumors of skin, 2 papillary syringocystadenomas, and 1 cylindroma were included. All samples were formalin-fixed and paraffin-erribedded. Two monoclonal cytokeratin ant.ibodies, MA-902 (specific for cytokeratin No. 8) and MA-903 (specific for cytokeratins No.1,5,10,11) were used. In normal eccrine and apocrine glands, MA-902 stains cells of the intradermal duct and secretory portion. While MA-903 stains cells of the intraepidermal and intradermal duct and myoepithelial cells of eccine and apocrine glands, S-100 protein is found in the secretory cells of the intradermalduct and secretory portion, while CEA stains the secretory and ductal cells of eccrine and apocrine glands. All sweat gland tumors we studied stained by 4 antibodies in variable positive rates, Based on these findings, we discuss the histogenesis of various sweat gland tumors.