RESUMO
The heparin-binding growth factor midkine (MK) is the product of a retinoic acid-responsive gene, and is implicated in neuronal survival and differentiation, and carcinogenesis. We previously reported that MK mRNA expression is elevated in neuroblastoma specimens at all stages, whereas pleiotrophin, the other member of the MK family, is expressed at high levels in favourable neuroblastomas. As MK is a secretory protein, it can be detected in the blood. Here, we show a significant correlation of the plasma MK level with prognostic factors of neuroblastomas. The plasma MK level was determined in 220 patients with neuroblastomas, and compared with that in children without malignant tumors (n=17, <500 pg ml(-1)). The plasma MK level became significantly elevated with advancing stages (stage 1: 445 pg ml(-1) (median), n=73; stage 2: 589, n=39; stage 3: 864, n=40; stage 4: 1445, n=56; and stage 4S: 2439, n=12). More importantly, a higher MK level was strongly correlated with poor prognostic factors: over 1 year of age (P=0.0299), MYCN amplification (P<0.0001), low TrkA expression (P=0.0005), nonmass screening, sporadic neuroblastomas (P<0.0001), and diploidy/tetraploidy (P=0.0007). Thus, these results demonstrate that the plasma MK level is a good marker for evaluating the progression of neuroblastomas. Moreover, considering the ability of antisense MK oligodeoxyribonucleotide to suppress tumour growth of colorectal carcinoma cells in nude mice, as recently reported, the present study suggests that MK is a possible candidate molecular target for therapy for neuroblastomas.
Assuntos
Biomarcadores Tumorais/análise , Proteínas de Transporte/sangue , Citocinas , Regulação Neoplásica da Expressão Gênica , Fatores de Crescimento Neural/sangue , Neuroblastoma/patologia , Animais , Proteínas de Transporte/biossíntese , Humanos , Técnicas Imunoenzimáticas , Lactente , Recém-Nascido , Camundongos , Camundongos Nus , Midkina , Fatores de Crescimento Neural/biossíntese , Neuroblastoma/genética , Oligorribonucleotídeos Antissenso , PrognósticoRESUMO
Midkine, a heparin-binding growth factor, plays a critical role in cell migration causing suppression of neointima formation in midkine-deficient mice. Here we have determined the molecules essential for midkine-induced migration. Midkine induced haptotaxis of osteoblast-like cells, which was abrogated by the soluble form of midkine or pleiotrophin, a midkine-homologous protein. Chondroitin sulfate B, E, chondroitinase ABC, B, and orthovanadate, an inhibitor of protein-tyrosine phosphatase, suppressed the migration. Supporting these data, the cells examined expressed PTPzeta, a receptor-type protein-tyrosine phosphatase that exhibits high affinity to both midkine and pleiotrophin and harbors chondroitin sulfate chains. Furthermore, strong synergism between midkine and platelet-derived growth factor in migration was detected. The use of specific inhibitors demonstrated that mitogen-activated protein (MAP) kinase and protein-tyrosine phosphatase were involved in midkine-induced haptotaxis but not PDGF-induced chemotaxis, whereas phosphatidylinositol 3 (PI3)-kinase and protein kinase C were involved in both functions. Midkine activated both PI3-kinase and MAP kinases, the latter activation was blocked by a PI3-kinase inhibitor. Midkine further recruited PTPzeta and PI3-kinase. These results indicate that PTPzeta and concerted signaling involving PI3-kinase and MAP kinase are required for midkine-induced migration and demonstrate for the first time the synergism between midkine and platelet-derived growth factor in cell migration.
Assuntos
Encéfalo/metabolismo , Proteínas de Transporte/farmacologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fator de Crescimento Derivado de Plaquetas/farmacologia , Proteínas Tirosina Fosfatases/metabolismo , Animais , Becaplermina , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Células Cultivadas , Condroitinases e Condroitina Liases/metabolismo , Colágeno/farmacologia , Citocinas/farmacologia , Sinergismo Farmacológico , Ativação Enzimática , Glicosaminoglicanos/farmacologia , Midkina , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-sis , Ratos , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Células Tumorais CultivadasRESUMO
Midkine (MK) is a growth factor with neurotrophic activities, and is expressed during the early stages of experimental cerebral infarction in rats in the zone surrounding the infarct. To evaluate in vivo activity of MK in preventing neuronal death, MK produced in yeast (Pichia pastoris) was administered into the brain ventricle immediately before occlusion of the bilateral common carotid artery of Mongolian gerbils. MK administration at the dose of 0.5-2 microg immediately before occlusion was found to ameliorate delayed neuronal death in the hippocampal CA1 region caused by transient ischemia 7 days after the insult. The hippocampal neurons of the MK-administered gerbils tended to degenerate 14 and 21 days after the insult, but their numbers remained higher than those in saline-administered controls; however, the hippocampal neurons were degenerated 28 days after the insult. MK administration at 2 h after occlusion did not ameliorate the neuronal death. These findings suggested that the therapeutic time window was narrow. The two to four times repeated administration of 2 microg MK immediately before and at 1, 2, or 3 weeks after the occlusion were not significantly different for the hippocampal neuronal death at 28 days after the insult compared with a single injection, but were significantly effective compared with vehicle administration alone. These findings suggested that the therapeutic time window was relatively narrow. The potent neuroprotective activity of MK observed in vivo suggested that MK might be useful as a therapeutic reagent for prevention of neuronal death in neurodegenerative diseases.
Assuntos
Isquemia Encefálica , Proteínas de Transporte/farmacologia , Morte Celular/efeitos dos fármacos , Citocinas , Hipocampo/efeitos dos fármacos , Fator de Crescimento Neural/farmacologia , Neurônios/efeitos dos fármacos , Animais , Isquemia Encefálica/patologia , Morte Celular/fisiologia , Gerbillinae , Hipocampo/patologia , Injeções Intraventriculares , Masculino , Midkina , Neurônios/fisiologia , Prosencéfalo/lesõesRESUMO
Cell-surface heparan sulfate proteoglycans participate in molecular events that regulate cell adhesion, migration, and proliferation. The present study was performed to elucidate whether glypican-2 plays a role in interactions of neurons with midkine (MK), a heparin-binding neuroregulatory factor. MK bound to heparan sulfate chains of glypican-2 in a manner similar to syndecan-3. Microbeads coated with MK or poly-L-lysine induced clustering of glypican-2 as well as syndecan-3. Substratum-bound MK or poly-L-lysine induced cell adhesion of N2a neuroblastoma cells, while only MK promoted neurite outgrowth of these cells. Ligation of cell-surface glypican-2 with MK or an antibody against epitope-tagged glypican-2 induced cell adhesion and promoted neurite outgrowth. These results verified that cell-surface glypican-2 bound to MK and suggested that MK-glypican-2 interactions participate in neuronal cell migration and neurite outgrowth. In addition, we observed different localization of epitope-tagged glypican-2 and syndecan-3 on the surface of N2a cells; the result suggested that they may play different roles in MK-mediated neural function.
Assuntos
Proteínas de Transporte/metabolismo , Citocinas , Proteoglicanas de Heparan Sulfato/metabolismo , Neuritos/metabolismo , Neurônios/citologia , Animais , Células COS , Adesão Celular , Cromatografia de Afinidade , Glipicanas , Humanos , Proteínas de Membrana , Midkina , Neurônios/metabolismo , Oligopeptídeos , Peptídeos/economia , Ligação Proteica , Ratos , Transfecção , Células Tumorais CultivadasRESUMO
Human midkine is expressed and secreted in the medium under the control of an AOX1 gene promoter in Pichia pastoris using its own secretion signal. The midkine precursor is properly processed to yield the correct amino-terminus of mature midkine. However, more than half of the product receives yeast specific mannosylations. The sites for the mannosylations were determined to be the three threonine residues in the carboxy-terminal region of human midkine. In order to obtain non-mannosylated midkine, alanine residues were substituted for the three threonine residues by site specific mutagenesis. HPLC and mass spectrometry confirmed that the mutant midkine contained almost no mannose residues. Despite the amino acid substitutions in the carboxy-terminal region, mutant human midkine, promoted CHO cell proliferation as well as normal midkine.
Assuntos
Proteínas de Transporte/genética , Citocinas/genética , Manose/química , Fatores de Crescimento Neural/genética , Pichia/metabolismo , Sequência de Aminoácidos , Animais , Células COS , Proteínas de Transporte/química , Citocinas/química , Humanos , Midkina , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Fatores de Crescimento Neural/química , Polímeros/química , Mapeamento por RestriçãoRESUMO
The expression of midkine (MK) was investigated in pancreatic ductal hyperplasias, atypical hyperplasias and adenocarcinomas induced by N-nitrosobis(2-oxopropyl)amine (BOP) in hamsters, and in hamster ductal adenocarcinoma cell lines (HPD-1NR, -2NR and -3NR). MK mRNA was clearly overexpressed in invasive pancreatic duct adenocarcinomas (PCs) and the three cell lines as assessed by northern blot analysis, and MK protein expression increased from ductal hyperplasia through atypical hyperplasias, intraductal carcinomas and invasive PCs by immunohistochemistry. The extent of overexpression of MK mRNA in PCs was almost the same as in hamster whole embryonic tissue. MK is reported to be a retinoid-responsive gene, but MK mRNA expression was not affected by treatment with all-trans retinoic acid (tRA) or N-(4-hydroxyphenyl)retinamide (4-HPR) in HPD-1NR cells. The results thus suggest that MK expression is involved in the development and progression of pancreatic ductal adenocarcinomas induced by BOP in hamsters, with loss of upregulation by retinoic acid.
Assuntos
Carcinoma Ductal Pancreático/metabolismo , Proteínas de Transporte/biossíntese , Citocinas , Neoplasias Pancreáticas/metabolismo , Animais , Antineoplásicos/farmacologia , Northern Blotting , Carcinoma Ductal Pancreático/induzido quimicamente , Proteínas de Transporte/genética , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Cricetinae , Modelos Animais de Doenças , Feminino , Fenretinida/farmacologia , Expressão Gênica/efeitos dos fármacos , Imuno-Histoquímica , Mesocricetus , Midkina , Nitrosaminas , Neoplasias Pancreáticas/induzido quimicamente , RNA Mensageiro/biossíntese , Tretinoína/farmacologiaRESUMO
The level of expression of midkine (MK), a heparin-binding growth factor, is increased in many types of human carcinomas. An enzyme-linked immunoassay, which utilizes a combination of rabbit and chicken antibodies revealed that serum MK level in the controls (n = 135) was 0.154 +/- 0.076 (mean +/- SD) ng ml(-1)with an apparent cut-off value as 0.5 ng ml(-1). Serum MK level was significantly elevated in the cancer patients (n = 150) (P< 0.001); 87% of the patients showed levels of more than 0.5 ng ml(-1). All ten types of cancer examined showed a similar profile of serum MK level. There was no or weak correlation between C-reactive protein level, a marker of inflammation, and serum MK level. Furthermore, in case of gastric carcinoma and lung carcinoma, patients with stage I carcinoma already showed elevated serum MK levels. The present results indicated that serum MK could serve as a general tumour marker with a good potential for clinical application.
Assuntos
Biomarcadores Tumorais/sangue , Carcinoma Papilar/sangue , Proteínas de Transporte/sangue , Citocinas , Neoplasias Gastrointestinais/sangue , Neoplasias Pulmonares/sangue , Fatores de Crescimento Neural/sangue , Neoplasias da Glândula Tireoide/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos/análise , Neoplasias da Mama/sangue , Carcinoma Hepatocelular/sangue , Galinhas , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Neoplasias Hepáticas/sangue , Masculino , Pessoa de Meia-Idade , Midkina , Coelhos , Sensibilidade e EspecificidadeRESUMO
Midkine is a heparin-binding growth factor with survival-promoting and migration-enhancing activities. In order to understand the regulation of midkine signaling, we isolated midkine-binding proteoglycans from day 13 mouse embryos, when midkine is intensely expressed. Deglycosylation followed by SDS/PAGE revealed various protein bands; one of these was identified as PG-M/versican by in gel trypsin digestion and sequencing the resulting peptides. PG-M/versican isolated from day 13 mouse embryos bound midkine with a Kd of 1.0 nM. Pleiotrophin/heparin-binding growth-associated molecule, which has a structure related to midkine, was also bound similarly. Digestion with chondroitinase ABC, AC-I or B abolished the binding to midkine. Heparin as well as chondroitin sulfate D and E inhibited the binding. After chondroitinase ABC digestion, the midkine-binding PG-M/versican released 4-sulfated, 6-sulfated, 2, 6-disulfated and 4,6-disulfated unsaturated disaccharides. These results suggest that midkine binds to a polysulfated domain in the chondroitin sulfate chain with a region of dermatan sulfate structure. This proteoglycan may modulate the midkine activity, as binding to midkine can enhance midkine action by concentrating it to the cell periphery or inhibit the action by competing with the binding to a signaling receptor.
Assuntos
Proteínas de Transporte/metabolismo , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Citocinas , Proteoglicanas/metabolismo , Sequência de Aminoácidos , Animais , Proteoglicanas de Sulfatos de Condroitina/isolamento & purificação , Sulfatos de Condroitina/metabolismo , Humanos , Lectinas Tipo C , Camundongos , Midkina , Dados de Sequência Molecular , VersicanasRESUMO
Midkine (MK) is a heparin-binding growth factor with migration-promoting and survival-promoting activities. To identify signaling receptor(s) of MK, membrane glycoproteins with MK-binding activity were isolated from day 13 mouse embryos by lectin- and MK-affinity chromatography. SDS-PAGE followed by protein sequence analysis revealed the presence of LDL receptor-related protein (LRP) and NCAM in the fraction. The dissociation constant of binding between LRP and MK was 3.5 nM. Receptor-associated protein (RAP), which interfered with the binding, inhibited MK-dependent survival of embryonic neurons. Brushin/megalin, which is also a high molecular weight protein belonging to the LDL receptor family, bound to MK less strongly than LRP. These findings suggest that LRP is a component of the receptor complex for MK.
Assuntos
Proteínas de Transporte/fisiologia , Citocinas , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/fisiologia , Fatores de Crescimento Neural/fisiologia , Receptores de Citocinas/química , Receptores de Citocinas/fisiologia , Receptores de Fatores de Crescimento/química , Receptores de Fatores de Crescimento/fisiologia , Receptores Imunológicos/química , Sequência de Aminoácidos , Animais , Embrião de Mamíferos , Complexo Antigênico da Nefrite de Heymann , Humanos , Cinética , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade , Glicoproteínas de Membrana/metabolismo , Camundongos , Midkina , Dados de Sequência Molecular , Moléculas de Adesão de Célula Nervosa/química , Proteínas Recombinantes/metabolismo , Transdução de SinaisRESUMO
Midkine (MK) is a heparin-binding growth factor involved in diverse biological phenomena, e.g. neuronal survival, carcinogenesis, and tissue repair. MK expression is detected mainly in the kidney in adult mice. In this study, we show that, at a dose that can induce recoverable renal damage and induce apoptosis, cisplatin (CDDP) transiently suppressed MK expression in mouse kidney. In vitro, CDDP suppressed MK expression and induced apoptosis in cultured G401 cells, a Wilms' tumor cell line. Exogenous MK protein partially rescued G401 cells from CDDP-induced apoptosis. MK enhanced the expression of Bcl-2, but not that of Bcl-x(L), in G401 cells in a dose-dependent manner, and it prevented the Bcl-2 reduction due to CDDP. Moreover, Bcl-2 expression in mouse kidney was also transiently suppressed by CDDP treatment, the expression profile being similar to that of MK. These results imply that MK exerts cytoprotective activity toward a damaging insult, presumably at least in part through enhancement of the expression of Bcl-2.
Assuntos
Antineoplásicos/farmacologia , Proteínas de Transporte/farmacologia , Cisplatino/farmacologia , Citocinas , Neoplasias Renais/patologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Tumor de Wilms/patologia , Animais , Apoptose/efeitos dos fármacos , Proteínas de Transporte/efeitos dos fármacos , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Rim/efeitos dos fármacos , Rim/patologia , Neoplasias Renais/tratamento farmacológico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Midkina , Proteínas Proto-Oncogênicas c-bcl-2/efeitos dos fármacos , Células Tumorais Cultivadas , Regulação para Cima , Tumor de Wilms/tratamento farmacológicoRESUMO
Neointima formation is a common feature of atherosclerosis and restenosis after balloon angioplasty. To find a new target to suppress neointima formation, we investigated the possible role of midkine (MK), a heparin-binding growth factor with neurotrophic and chemotactic activities, in neointima formation. MK expression increased during neointima formation caused by intraluminal balloon injury of the rat carotid artery. Neointima formation in a restenosis model was strongly suppressed in MK-deficient mice. Continuous administration of MK protein to MK-deficient mice restored neointima formation. Leukocyte recruitment to the vascular walls after injury was markedly decreased in MK-deficient mice. Soluble MK as well as that bound to the substratum induced migration of macrophages in vitro. These results indicate that MK plays a critical role in neointima formation at least in part owing to its ability to mediate leukocyte recruitment.
Assuntos
Angioplastia com Balão/efeitos adversos , Arteriopatias Oclusivas/terapia , Proteínas de Transporte/genética , Citocinas , Fatores de Crescimento Neural/genética , Túnica Íntima/patologia , Animais , Arteriosclerose/terapia , Arterite/terapia , Estenose das Carótidas/terapia , Movimento Celular , Células Cultivadas , Expressão Gênica , Macrófagos/citologia , Masculino , Camundongos , Camundongos Mutantes , Midkina , Músculo Liso Vascular , Ratos , Ratos Sprague-DawleyRESUMO
Midkine is a heparin-binding polypeptide which is implicated in the control of development and repair of various tissues. Recognition of sulfate groups in glycosaminoglycans is important for its function. To elucidate further its mechanism of action, the interactions of midkine with sulfated glycolipids were studied. Of various glycolipids and lipids examined, midkine bound strongly to sulfatide and cholesterol-3-sulfate (CHO-3-SO4) in a dose-dependent manner but failed to bind to other standard glycolipids and lipids. The properties of midkine binding to sulfatide and to CHO-3-SO4 differed in their sensitivity to inhibition by anionic polysaccharides, salt concentration and unlabeled midkine. Heparin inhibited midkine binding to sulfatide but weakly inhibited its binding to CHO-3-SO4. Liposomes bearing sulfatide carried out significant interactions with immobilized midkine, whereas those bearing CHO-3-SO4 did not. Incorporation of sulfatide into 32D cells and trypsinized COS cells enhanced 125I-labelled midkine binding, whereas incorporation of ganglioside or galactosylceramide had no effect. Furthermore, sulfatide-incorporated cells enhanced cell attachment to midkine-coated coverslips. These results indicate that midkine binds to sulfatide under physiological conditions and the midkine-sulfatide interaction may be important in controlling cell attachment.
Assuntos
Proteínas de Transporte/metabolismo , Citocinas , Sulfoglicoesfingolipídeos/metabolismo , Adsorção , Animais , Células COS/citologia , Células COS/metabolismo , Adesão Celular/fisiologia , Membrana Celular/metabolismo , Lipossomos/metabolismo , Midkina , Propriedades de SuperfícieRESUMO
We have examined the expression of midkine (MK), a neurotrophic factor with heparin-binding activity, in human esophageal cancer cells. Seven esophageal cell lines tested expressed the transcript and 8 out of 14 human esophageal tumor specimens were positively stained with anti-MK antibody, while surrounding normal esophageal tissues in these specimens were not stained. The 5'-flanking, 2.3 kb genomic region of the MK gene was shown to drive the transcription of a reporter gene in the esophageal cell lines in a cis acting manner. Forced expression in esophageal cancer cells of herpes simplex virus-thymidine kinase gene mediated by the flanking region of the MK gene conferred sensitivity to a prodrug, ganciclovir. The 5'-upstream region of the MK gene thus possesses putative promoter activity which can be used for suicide gene-based gene therapy for esophageal cancer.
Assuntos
Proteínas de Transporte/genética , Citocinas , Neoplasias Esofágicas/terapia , Regulação Neoplásica da Expressão Gênica/fisiologia , Terapia Genética/métodos , Proteínas de Neoplasias/genética , Fatores de Crescimento Neural/genética , Idoso , Antivirais/uso terapêutico , Feminino , Ganciclovir/uso terapêutico , Técnicas de Transferência de Genes , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Midkina , Regiões Promotoras Genéticas , Células Tumorais CultivadasRESUMO
The expression of midkine (MK) in lung tumors induced by N-nitrosobis(2-hydroxypropyl)amine (BHP) in rats was examined. The animals were administered 2000 p.p.m. of BHP in their drinking water for 12 weeks, then maintained without further treatment until being killed 20-28 weeks after the beginning of the experiment. MK mRNA expression of adenocarcinomas and squamous cell carcinomas assessed by means of the reverse transcriptase-polymerase chain reaction and northern blot analysis was significantly higher than in rat embryonic tissues (positive controls) and contrasted strongly with the lack in normal lungs. MK protein was detected immunohistochemically in 58.3% of alveolar hyperplasias, 92.3% of adenomas and 100% of adenocarcinomas and squamous cell carcinomas. The extent of staining significantly increased along with malignant progression in adenomatous (pre-)neoplastic lesions and tended to become more pronounced with malignant progression in squamous lesions. The results suggest that MK may play some essential roles in the development and progression of lung tumors induced by BHP in rats.
Assuntos
Carcinógenos/toxicidade , Proteínas de Transporte/genética , Citocinas , Neoplasias Pulmonares/genética , Nitrosaminas/toxicidade , Adenocarcinoma/induzido quimicamente , Adenocarcinoma/genética , Adenocarcinoma/patologia , Animais , Sequência de Bases , Northern Blotting , Carcinoma de Células Escamosas/induzido quimicamente , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Primers do DNA , Feminino , Imuno-Histoquímica , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/patologia , Masculino , Midkina , Gravidez , RNA Mensageiro/genética , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
A heterozygote for congenital deficiency of plasma plasmin in inhibitor had hemorrhagic episodes repeatedly after the age of 79. Before the age of 79, he had not exhibited any hemorrhagic tendency and did not have abnormal bleeding even after surgical operations. Although heterozygotes for congenital deficiency of this inhibitor usually have no or only a mild hemorrhagic tendency, this case suggests that they may exhibit severe hemorrhagic tendency when they reach advanced ages because of age-related vascular changes producing hemostatic imbalance.
Assuntos
Envelhecimento/genética , Antifibrinolíticos/metabolismo , Hemorragia/genética , Heterozigoto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/sangue , Antifibrinolíticos/uso terapêutico , Fibrinólise/efeitos dos fármacos , Predisposição Genética para Doença , Hemorragia/sangue , Hemostasia/efeitos dos fármacos , Humanos , Masculino , LinhagemRESUMO
cDNA of human alpha-1,3/4-fucosyltransferase (Fuc-TIII) was placed under the control of the chicken beta-actin promoter and cytomegalovirus enhancer, then introduced into male pronuclei of fertilized mouse eggs. A transgenic mouse line thus obtained exhibited enhanced expression of Lex (4C9) antigen in endothelial cells located in the glomerulus, sinusoidal capillaries of the liver and capillaries of the heart. Furthermore, in the transgenic mice, sialyl dimeric Lex (FH6) and sialyl Lea (2D3) antigens were strongly expressed in the glomerular endothelial cells.
Assuntos
DNA Complementar/biossíntese , Fucosiltransferases/genética , Antígenos CD15/genética , Animais , Sequência de Bases , Configuração de Carboidratos , DNA Complementar/química , Rim/imunologia , Fígado/imunologia , Pulmão/imunologia , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Miocárdio/imunologiaRESUMO
The cDNA of murine alpha-1,3-galactosyltransferase was placed under the control of the beta-actin promoter and cytomegalovirus enhancer, then introduced into male pronuclei of fertilized mouse eggs. The three transgenic mouse lines obtained were analysed for the expression of the transferase by staining with Griffonia simplicifolia agglutinin I-B4 (GSI-B4), which is alpha-galactosyl specific. Compared with wild-type mice, all lines of transgenic mice expressed GSI-B4 binding sites more intensely in the renal tubular brush border and lung alveolar epithelium, and newly expressed them in the photoreceptor outer segments, goblet cells of the small intestine and around spermatogonia. GSI-B4 binding sites were also detected in the liver of some transgenic mice. Even though the introduced enzyme gene was expressed in embryos, it did not severely hinder embryogenesis. The transgenic mice tended to secrete more proteins in the urine than the wild type. Furthermore, low body weights, partial damage to hair growth and early death occurred more frequently in the transgenic mice.
Assuntos
Galactosiltransferases/biossíntese , Animais , Sítios de Ligação , Sequência de Carboidratos , DNA Complementar , Epitélio/metabolismo , Feminino , Galactosiltransferases/genética , Galactosiltransferases/metabolismo , Túbulos Renais/metabolismo , Lectinas/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Microvilosidades/metabolismo , Dados de Sequência Molecular , Alvéolos Pulmonares/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
The efficacy of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on neutropenia was evaluated in 14 patients with AIDS and AIDS-related complex (ARC). In all patients, including 11 neutropenic patients, 100 or 200 micrograms/m2 of rhG-CSF significantly increased the neutrophil counts. The response was greater in patients with higher neutrophil counts before the treatment, and was also dose-dependent. Although the effect seemed to be less potent, the agent also increased the neutrophil counts even when zidovudine (azidothymidine, AZT) and other myelosuppressive antiviral agents were administered simultaneously. These observations indicate that rhG-CSF may be beneficial in preventing and treating some secondary infections, and will make it easier to continue therapy with antiviral agents in patients with AIDS or ARC.