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PubMed1996

Increased frequency of organ-specific cardiac antibodies in healthy relatives of patients with dilated cardiomyopathy: evidence for autoimmunity in Polish families.

BACKGROUND AND HYPOTHESIS: Autoantibodies represent markers of autoimmune involvement and are found with increased frequency in patients and their symptom-free relatives at risk compared with normal controls. Cardiac-specific autoantibodies, detected by immunofluorescence, were found in 20% of symptom-free relative of patients with dilated cardiomyopathy (DCM) from England and Italy. The role of autoimmunity may vary in DCM patients from Poland due to ethnic differences in genetic susceptibility to autoimmune disease. METHODS: We assessed the frequency of the organ-specific cardiac autoantibodies in 162 symptom-free relatives of DCM patients [85 male, mean (SD) age 27 (18) years] and 80 control subjects from Poland. Familial DCM (> 1 affected member) was present in 4 families, nonfamilial DCM in the remaining 24 pedigrees. We performed antibody screening and noninvasive cardiological assessment in the whole group. RESULTS: The frequency of cardiac-specific autoantibodies was higher among patients with documented DCM (probands and relatives) (50%) and their symptom-free relatives (38%) than in unrelated normal subjects (10%; p = 0.0001). In 24 (86%) of the pedigrees studied, autoantibodies were found in the proband and/or in at least one family member and tended to be more common in familial than in nonfamilial DCM (50 vs. 35%, p = NS). Echocardiographic indices of left ventricular size and function were similar in relatives with and without detectable antibodies. CONCLUSIONS: The presence of cardiac-specific autoantibodies in symptom-free relatives of DCM patients provides evidence for autoimmunity in the majority (86%) of our pedigrees, including both familial and nonfamilial forms of DCM.

Adolescent↗
PubMed1994

Molecular cloning of two different ACC synthase PCR fragments in carnation flowers and organ-specific expression of the corresponding genes.

Degenerate oligonucleotides to highly conserved regions of 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (EC 4.4.1.14), the key enzyme in ethylene biosynthesis, were used to prime the synthesis and amplification of fragments of about 1,180 bp by polymerase chain reaction (PCR) in samples of cDNA to total RNA isolated from senescing carnation (Dianthus caryophyllus) flowers. Two putative ACC synthase PCR clones were isolated one of which was identical to the sequence of a carnation ACC synthase cDNA clone (CARACC3) recently isolated by Park et al. (Plant Mol Biol 18 (1992) 377-386). The other clone (CARAS1) was ca. 66% homologous at the amino acid level to CARACC3. For both ACC synthase clones, specific oligonucleotides were synthesized and, using PCR, we were able to distinguish between the two ACC synthase transcripts in samples of total RNA isolated from different carnation flower parts and leaves. DNA blots of PCR fragments revealed that, in flowers, both ageing and ethylene stimulated the occurrence of these transcripts in an organ-specific way. CARACC3 was more abundant in RNA from the petals whereas CARAS1 was more abundant in RNA from the styles. Despite a high ethylene production observed in ovaries, the level of both transcripts was low, suggesting the existence of a third ACC synthase gene that is specifically expressed in the ovary. Transcript levels in leaves were low irrespective of treatment.

Amino Acid Sequence↗
PubMed2003

An HLA-peptide mimics organ-specific antigen in autoimmune uveitis: its role in pathogenesis and therapeutic induction of oral tolerance.

Autoimmune uveitis is a sight threatening disease, which is conventionally treated with immunosuppressive medication. New treatment strategies include immunological approaches and aim at antigen specificity like oral tolerance. A peptide from the sequence of certain HLA-class I molecules plays a central role in the pathogenesis. When T cells recognize the HLA-peptide and are activated they are enabled to pass the blood-retina barrier. In the eye they recognize a cross-reactive organ-specific peptide and cause inflammation, which presents as uveitis. Here, we used the HLA-peptide as oral tolerogen to treat uveitis patients in an open study. All patients showed a positive therapeutic response and could reduce their long-lasting conventional immunosuppressive treatment. We did not observe any side effects. Moreover, side effects from conventional therapy could be reduced significantly.

Autoimmune Diseases↗
PubMed1991

The maize cytosolic glyceraldehyde-3-phosphate dehydrogenase gene family: organ-specific expression and genetic analysis.

The distribution of the cytosolic glyceraldehyde-3-phosphate dehydrogenase gene family (Gpc) in the maize genome was investigated; a genetic variant of glyceraldehyde-3-phosphate dehydrogenase activity is also described. Restriction fragment length polymorphism analysis of an F2 population shows that the variant is not linked to the three known Gpc genes. However, this trait is linked to one of two genomic DNA fragments that hybridize to a fragment of the Gpc3 coding region, implying the existence of a fourth Gpc gene. Antibodies and cDNA clones were used to investigate the organ-specific expression of the Gpc genes. Results were compared with the expression of the Gpc genes. Results were compared with the expression of the alcohol dehydrogenase 1 (Adh1) gene. RNA and protein levels were examined in seedling roots and shoots, as well as the leaves, developing endosperm and embryo, and the aleurone. In general, it was found that Gpc3 expression behaves in parallel with Adh1 in these organs, and protein levels closely parallel that of RNA for each gene examined. Both Gpc3 and Adh1 show a marked increase in expression during endosperm development, reaching a maximum 15 days after pollination, but no expression is detected in the leaf. Gpc1 expression is similar to that of Gpc2, with an overall decrease in the level of RNA during endosperm development. This expression is discussed in terms of the common sequences found upstream of genes expressed in the developing maize seed.

Blotting, Northern↗
PubMed1995

Characterization of organ-specific immunoliposomes for delivery of 3',5'-O-dipalmitoyl-5-fluoro-2'-deoxyuridine in a mouse lung-metastasis model.

A previous study has shown that lipophilic prodrugs can be delivered efficiently to normal lung endothelium by incorporation into liposomes covalently conjugated to monoclonal antibody (mAb) 34A against the lung endothelial anticoagulant protein thrombomodulin. In the present study, the potential use of these lung-targeted immunoliposomes (34A-liposomes) for delivery of a lipophilic prodrug, 3',5'-O-dipalmitoyl-5-fluoro-2'-deoxyuridine (dpFUdR), to the tumor-bearing lung was examined using BALB/c mice bearing experimental lung metastasis induced by i.v. injection of EMT-6 mouse mammary tumor cells. Immunohistochemical examination of the tumor-bearing lung showed specificity of mAb 34A to lung endothelium. Tumor cells appeared to localize just outside of the normal blood vessels and were within a small diffusion distance from the mAb 34A-binding sites. 111In-labeled 34A-liposomes containing monosialoganglioside (GM1) were prepared that included [3H]-dpFUdR at 3.0 mol% in the lipid mixture. In vitro cell binding studies further demonstrated that 34A-liposomes bound specifically to normal mouse lung cells that expressed thrombomodulin but not to EMT-6 cells. Biodistribution study showed efficient and immunospecific accumulation of [3H]-dpFUdR incorporated into 34A-liposomes in the lung at a level parallel with that of 111In-labeled 34A-liposomes, indicating that the drug is delivered to the target organ in intact liposomes. Liposomal dpFUdR appeared to be metabolized in the lung to the parent drug FUdR at a rate slower than in the liver and spleen. Furthermore, treatment of lung-metastasis-bearing mice with dpFUdR incorporated into 34A-liposomes on days 1 and 3 after tumor cell injection resulted in a significant increase in the median survival time of treated mice as compared with control mice (%T/C value, 165%). dpFUdR either dispersed in emulsion or incorporated into antibody-free liposomes was ineffective in prolonging the survival of mice. These results indicate the potential effectiveness of organ-specific immunoliposomes containing a lipophilic prodrug for the targeted therapy of metastatic tumors.

Animals↗
PubMed2001

Possible role of organ-specific autoantigen for Fas ligand-mediated activation-induced cell death in murine Sjögren's syndrome.

Activation-induced cell death (AICD) is a well-known mechanism of peripheral T cell tolerance that depends upon an interaction between Fas and Fas ligand (FasL). In this study, we demonstrate that the administration of a soluble form of anti-FasL Ab, FLIM58, results in severe destructive autoimmune exocrinopathy in the murine model of human Sjögren's syndrome (SS), and we found that an organ-specific autoantigen may play an important role on down-modulation of AICD. A high titer of serum autoantibodies against 120-kDa alpha-fodrin autoantigen was detected in the FLIM58-treated mice, and splenic T cell culture supernatants contained high levels of IFN-gamma. In vitro T cell apoptosis assay indicated that FasL-mediated AICD is down-regulated by autoantigen stimulation in spleen cells from the murine SS model, but not from Fas-deficient MRL/lpr mice and FasL-deficient MRL/gld mice. FasL undergo metalloproteinase-mediated proteolytic processing in their extracellular domains, resulting in the release of soluble trimeric ligands (soluble FasL). We showed that the processing of soluble FasL occurs in autoantigen-specific CD4(+) T cells, and that a significant increase in expressions of metalloproteinase-9 mRNA was observed in spleen cells from SS model mice. These findings indicate that the increased generation of soluble FasL inhibits the normal AICD process, leading to the proliferation of effector CD4(+) T cells in the murine SS model.

Animals↗
PubMed1996

Interferon and prednisone therapy in chronic hepatitis C with non-organ-specific antibodies.

BACKGROUND/AIMS: The relationship between hepatitis C virus and autoimmunity is controversial. The issue is particularly relevant in those patients with hepatitis C virus infection and serum autoantibodies in whom steroids can exacerbate viral replication and interferon can lead to decompensated liver disease. The aim of this study was to evaluate the response to a course of prednisone or interferon-alpha 2b. METHODS/RESULTS: The 12 study patients had biopsy-proven chronic hepatitis, serum HCV-RNA (by nested polymerase chain reaction) and non-organ-specific antibodies (eight with liver and kidney microsomal antibodies and four with antinuclear antibodies). Eight of these 12 patients received a 4-month course of prednisone (0.5 mg/kg per day), which increased alanine aminotransferase (mean +/- SE) (174 +/- 31 vs 252 +/- 18 U/l, p < 0.05) and bilirubin levels (0.96 +/- 0.17 vs 1.42 +/- 0.18 mg/dl, p = 0.09), without changing liver histology (Knodell index, 13.6 +/- 0.4 vs 13.1 +/- 0.3). Subsequent treatment with interferon in the 12 patients reduced serum alanine aminotransferase levels (170 +/- 20 vs 41 +/- 7 U/l, p < 0.0001) and portal and lobular inflammation (Knodell index, 13.8 +/- 0.5 vs 8.4 +/- 0.2, p < 0.001). A complete response to interferon was observed in ten of these patients (83%), eight of whom had previously been treated with prednisone. Serum HCV-RNA level decreased in interferon responders. A sustained response 1 year after withdrawal of interferon was seen in only five patients (41%). CONCLUSIONS: Patients with chronic hepatitis C and autoantibodies show a favorable response to interferon, but not to prednisone. The latter regimen can exacerbate liver necrosis in these subjects. The presence of autoantibodies in hepatitis C patients does not modify the response to interferon.

Adult↗
PubMed1976

Allograft immunity to histocompatibility and organ-specific antigens.

An experimental model has been developed in the dog in which a renal allograft was placed in the neck, leaving one of the dog's own kidney in situ. Five nonimmunosuppressed pairs of dogs have been studied by using the leucocyte migration test (LMT) as an in vitro measure of cell-mediated immunity. Antigen preparations from leucocytes, kidney, liver, and skeletal muscle from both the kidney donor and the recipient were used in the LMT in order to study responses against transplantation and organ-specific antigens. Inhibition of migration with donor-specific leucocyte and kidney antigens was detectable prior to clinical evidence of rejection, which was confirmed histologically. Concurrently, inhibition was also observed with autologous kidney antigen and histological damage was noted in the recipient's own nontransplanted kidney, accompanied by increasing proteinuria. Autologous serum withdrawn daily and added to the test culture medium abolished the inhibition of migration, thus suggesting the development of blocking factor.

Animals↗
PubMed1992

Pharmacokinetics and organ specific metabolism of glycine-extended and amidated gastrin in sheep.

Glycine (Gly)-extended gastrin has been described as the inactive precursor form of the biologically active amidated gastrin. The ratio of Gly-extended to amidated gastrin is higher in the circulation than in tissue, suggesting either differential secretion and/or metabolism. Although the distribution of the precursor form is similar in tissue and circulation to its amidated product, the significance of measurable levels of precursor peptide in the circulation is unknown. In this study, we have examined the pharmacokinetic properties and organ-specific metabolism of both the Gly-extended and the amidated forms of gastrin-17 (G-17-Gly and G-17-amide) in the conscious sheep. The metabolic clearance rate, half disappearance time, and production rates were similar for both G-17-Gly and G-17-amide. G-17-Gly was extracted across the head, kidney, and lung but not across the gut and liver. Similarly, G-17-amide was extracted across the head, gut, lung, and kidney but not across the liver. G-17-Gly had no biological activity as evidenced by its failure to stimulate somatostatin secretion nor was there any measurable conversion to amidated gastrin in the circulation. We conclude that the presence of G-17-Gly in the circulation is not the result of a slower clearance and that circulating G-17-Gly is not a precursor for circulating gastrin-amide. The results of this study provide important baseline data for understanding the dynamics of the precursor product relationship between G-Gly and G-amide.

Amino Acid Sequence↗
PubMed1993

[The roles of cytokine in organ-specific tumor metastasis].

The production of cytokines by tumor cells has been suggested as the molecular perturbation responsible for the development of malignant tumors. The behavior of tumor cells in animals is presumed to be affected by these factors, which include such hematopoietic cytokines as GM-CSF, IL-1, and IL-6. Here, we report findings demonstrating that GM-CSF is produced by many murine transplantable tumors with metastatic ability in the lungs, and IL-6 and/or IL-1 are produced by the tumors metastatic in the liver. We discuss the notion that the particular organ or organs in which tumor cells metastasize may be associated with the type of cytokines produced by the tumors. Metastatic spread requires interactions of tumor cells with components of the extracellular matrix of host tissues or with other cells, almost all of which depend on cell surface determinants such as cell adhesion molecules. We also discuss the possibility that the expression and adhesive potentials of adhesive protein (CD44) may be regulated by the cytokine (GM-CSF) excreted from the tumor cells. We then emphasize the possibility that both gene expression of cytokines and adhesive proteins play a critical role in tumor metastasis and in determining organ specificity in metastasis.

Animals↗
PubMed2007

ATG genes involved in non-selective autophagy are conserved from yeast to man, but the selective Cvt and pexophagy pathways also require organism-specific genes.

ATG genes encode proteins that are required for macroautophagy, the Cvt pathway and/or pexophagy. Using the published Atg protein sequences, we have screened protein and DNA databases to identify putative functional homologs (orthologs) in 21 fungal species (yeast and filamentous fungi) of which the genome sequences were available. For comparison with Atg proteins in higher eukaryotes, also an analysis of Arabidopsis thaliana and Homo sapiens databases was included. This analysis demonstrated that Atg proteins required for non-selective macroautophagy are conserved from yeast to man, stressing the importance of this process in cell survival and viability. The A. thaliana and human genomes encode multiple proteins highly similar to specific fungal Atg proteins (paralogs), possibly representing cell type-specific isoforms. The Atg proteins specifically involved in the Cvt pathway and/or pexophagy showed poor conservation, and were generally not present in A. thaliana and man. Furthermore, Atg19, the receptor of Cvt cargo, was only detected in Saccharomyces cerevisiae. Nevertheless, Atg11, a protein that links receptor-bound cargo (peroxisomes, the Cvt complex) to the autophagic machinery was identified in all yeast species and filamentous fungi under study. This suggests that in fungi an organism-specific form of selective autophagy may occur, for which specialized Atg proteins have evolved.

Amino Acid Sequence↗
PubMed1996

The spinach AtpC and AtpD genes contain elements for light-regulated, plastid-dependent and organ-specific expression in the vicinity of the transcription start sites.

Run-on assays with isolated nuclei demonstrate that the transcription rates of AtpC and AtpD (gene products: the CF1 subunits gamma and delta of the chloroplast ATP synthase) are comparable in spinach seedlings. However, chimeric GUS gene fusions with 5'-flanking regions of the AtpC gene direct an approximately 10-fold lower GUS level in transgenic tobacco compared with equivalent fragments from the AtpD gene. Both promoters contain sequences in the vicinity of the respective TATA boxes, which are sufficient to direct light-regulated, plastid-dependent and organ-specific expression of the GUS gene. In contrast, the upstream regions of both promoters differ the higher GUS level directed by the AtpD promoter is caused by enhancer-like elements located upstream of the region involved in the regulated expression, while nucleotides upstream of -73 in the AtpC promoter contribute relatively little to the promoter activity. 5'-Deletion analyses and site-directed mutagenesis studies indicated that the -73/-48 bp AtpC region contains cis-elements crucial for this regulated expression. If five nucleotides within this region (-59/-55) are exchanged, the GUS gene is constitutively expressed and the activity in etiolated seedlings, in seedlings with photobleached plastids and in roots increases to the level detectable in green cotyledons. It is concluded that signal transduction pathways from different regulators converge prior to gene regulation and that these five nucleotides are part of a cis-element which functions as a repressor in darkness, in tissues with impaired plastids and in roots.

Base Sequence↗
PubMed1988

Organ-specific and developmental regulation of the nopaline synthase promoter in transgenic tobacco plants.

Control regions of the nopaline synthase (nos) gene have been widely used to express foreign genes in plants since the promoter is active in a wide variety of plant tissues. We report here the characteristics of the nos promoter activity in transgenic tobacco (Nicotiana tabacum) plants at various developmental stages. The promoter was highly active in the lower parts of a plant and gradually decreased in the upper parts. This vertical gradient was maintained throughout plant growth until the flowering stage when the overall promoter strength decreased significantly in the vegetative organs. However, in various flower organs, the nos promoter activities increased dramatically. Higher activity was observed in calyx, corolla, and stamens although the maximum promoter activity in each organ was found at different stages of flower development. The promoter activity in pistils was low and gradually increased in the ovaries after anthesis. In developing fruits, the nos promoter activity was strongly induced during the mid-stage of embryogenesis. These results indicate that the expression of the nos promoter is developmentally regulated and organ specific in transgenic tobacco plants.

Journal Article↗
PubMed1989

The Pea rbcS-3A Promoter Mediates Light Responsiveness but not Organ Specificity.

The expression of the pea rbcS-3A gene is responsive to light and restricted to chloroplast-containing cells. Previously, we identified transcriptional elements between -410 and -50 relative to the transcription start site as being sufficient for this regulated expression. Here we investigate the role of the promoter region (-50 to +15) in rbcS-3A expression. We demonstrate an interaction between the promoter and upstream sequences located between -189 and -166, which is important for high level expression. In addition we show that, when the rbcS promoter is driven by a weak test enhancer, it can confer light-responsive but not organ-specific expression upon a bacterial reporter gene.

Journal Article↗
PubMed1993

Developmental and organ-specific changes in DNA-protein interactions in the tomato rbcS3B and rbcS3C promoter regions.

Sites of DNA-protein interaction were mapped in the promoter regions of two of the five genes encoding the small subunit of ribulose-1,5-bisphosphate carboxylase (rbcS) in tomato. The two genes, designated rbcS3B and -3C, are actively transcribed in cotyledons of light-grown seedlings and in leaves, but are transcriptionally inactive cotyledons of dark-grown seedlings, in young and mature tomato fruit, and in roots. The combination and order of conserved DNA sequence elements in the promoter regions of the two genes are essentially identical, but differ considerably from that found in the promoters of the other three tomato rbcS genes, which show different transcription patterns. Nuclear extracts from cotyledons of 7-day-old tomato seedlings, and from leaves and young tomato fruit of mature plants defined multiple DNase I-protected sites in the promoter regions of both genes. The protection patterns were organ-specific, and encompassed previously identified conserved DNA sequence motifs as well as uncharacterized sequences. In contrast, nuclear extracts from mature tomato fruit and roots of 7-day-old seedlings failed to protect any of the promoter sequences, implying that DNA-binding proteins required for transcription of rbcS3B and -3C are inactive in these organs. These results are somewhat surprising since DNA-binding proteins from cotyledons of dark-grown seedlings and young fruit interact with the two promoters, although rbcS3B and -3C are not transcribed in these organs. The basis for transcriptional regulation of these two genes is discussed and the detailed pattern of DNase I protection in the promoter regions of the two genes is presented.

Base Sequence↗
PubMed1984

Measurement of total and organ-specific norepinephrine kinetics in humans.

A variety of biochemical tests, most notably measurement of the plasma concentration of norepinephrine, have been used to quantify overall sympathetic nervous system activity in humans. Plasma norepinephrine values provide a fallible index of sympathetic activity in that they are dependent in part on the rate of removal of norepinephrine from plasma. Measurement of the rate of release of norepinephrine to plasma is a better guide to overall sympathetic nervous tone because it avoids this confounding influence of norepinephrine plasma clearance. The overall norepinephrine spillover measurement, however, suffers from one major limitation: the sources of the released norepinephrine are not identified. Recently developed radiotracer techniques allow the estimation of regional sympathetic nervous activity from measurements of the organ-specific norepinephrine spillover rate. We find that the lungs are the main source of norepinephrine release to plasma, with mean pulmonary norepinephrine spillover of 159 ng/min constituting 40% of total norepinephrine release. Pulmonary norepinephrine release exceeded the combined norepinephrine spillover from the heart (3%), kidneys (17%), and hepatomesenteric circulation (8%).

Humans↗