[A comparative study of the ELISA and IF methods for antinuclear antibody test]

A new ELISA method for antinuclear antibody(ANA) test was investigated for its clinical usefulness by comparison with a widely used IF method. Both methods used Hep 2 cells as a substrate. ELISA method showed good reproducibility in both within-run(CV = 5.1 approximately 8.7%) and between-run(CV = 8.1 approximately 9.6%) assays. ROC analysis revealed that ELISA method had a higher sensitivity and an equal specificity as compared to IF method. Application of an auto analyzing system to ELISA method could induce the improvement of efficacy and labor saving. The coincidence rate between ELISA and IF methods was 78.6% on the samples from 887 patients with various disorders. In patients with drug induced lupus or connective tissue diseases except for rheumatoid arthritis, the discrepancies were caused mainly by the higher sensitivity of ELISA method. However, the ELISA test was less sensitive for the ANAs showing granular, nuclear membrane, or anti-PCNA antibody like staining patterns by IF method. In conclusion, ELISA method is useful for detecting ANAs because of its high sensitivity and efficiency, though it still has some points to be improved.

Microdissection-mediated selection of chromosome region-specific cDNAs

K562 is a cell line with two acrocentric marker chromosomes containing abnormally banded regions (ABRs), derived from a Ph-positive chronic myelogenous leukemia (CML) patient. Using reverse and forward chromosome painting FISH analysis, we found that 9q34, 13q31, and 22q11 regions co-amplified in the ABRs-bearing acrocentric marker chromosomes of K562. Utilizing the ABRs of the cell line as target DNA for cDNA selection, we established a simple procedure for chromosome region-specific cDNA isolation. After first strand cDNA synthesis from fetal brain mRNAs, short fragment cDNAs (sf-cDNAs) were synthesized with a two-step amplification system by use of our modified Degenerate Oligonucleotide Primed Shuttle Polymerase Chain Reaction (DOP-Shuttle-PCR) method. The sf-cDNAs were hybridized onto RNase A treated metaphases from K562, and the ABRs were microdissected and reamplified with DOP-Shuttle-PCR primer-II. The reamplified sf-cDNAs were cloned into a pBluescript vector. Twenty randomly chosen clones were sequenced and classified into 8 groups. Three out of the 8 grouped clones had been mapped to the long arm of chromosome 22 (22q11), whereas the other 5 were novel cDNAs. Quantitative Southern blot analysis indicated that 7 out of the 8 grouped clones (87.5%) were derived from the co-amplified regions.

Hypoxic effects on cholesterol metabolism of cultured rat aortic and brain microvascular endothelial cells, and aortic vascular smooth muscle cells

We investigated hypoxic effects on cholesterol metabolism in cultured brain microvascular endothelial cells (BEC), aortic endothelial cells (AEC) and aortic vascular smooth muscle cells (VSMC) from rat. In control conditions, acid lipase activities in BEC and AEC were higher than that in VSMC. Acyl-Coenzyme A: cholesterol acyltransferase (ACAT) activities in control cells of BEC and AEC were lower than that of VSMC. Hypoxic treatment caused decreased acid lipase activity. ACAT activity decreased in VSMC. High pressure lipid chromatography (HPLC) study showed that hypoxia caused decreased contents of cholesterol and cholesteryl esters especially in AEC. We suggested that there is different cholesterol metabolism in the hypoxic treatment among endothelial cells and smooth muscle cells.

Induction of c-fos protooncogene transcription and apoptosis by delta 12-prostaglandin J2 in human Pl-21 myeloid leukemia and RC-K8 pre-B lymphoma cells

delta 12-prostaglandin J2 (PGJ2) is a dehydration product of PGD2 and thought to be the most potent antitumor agent among prostaglandin compounds. We examine the cytotoxic effects of PGJ2 on the cell growth of leukemia/lymphoma cells. PGJ2 inhibited the growth of both human PL-21 myeloid leukemia and RC-K8 pre-B lymphoma cells in culture in a dose-dependent manner with fragmentation of nucleus and formation of apoptotic body. Agarose gel electrophoresis revealed DNA ladder formation in the cells treated with PGJ2. Furthermore, PGJ2 induced a rapid and transient expression of apoptosis-related protooncogene, c-fos, in both cells. The gene transcriptional rate was remarkably increased approximately 3.3-fold in PGJ2 treated cells, but the stability of c-fos mRNA was not significantly changed. Inhibition of de novo protein synthesis with cycloheximide increased c-fos mRNA stability but not abrogated PGJ2-induced c-fos transcription. These data suggest that PGJ2 can induce apoptosis of human leukemia/lymphoma cells and the rapid activation of c-fos protooncogene transcription in which de novo protein synthesis is not required.

Isolated recombinant domain of von Willebrand factor displaying increased sensitivity to ristocetin

Type 2B von Willebrand disease is characterized by an abnormal von Willebrand factor molecule with increased affinity for the platelet glycoprotein (GP) Ib-IX receptor. A diagnostic feature of type 2B von Willebrand disease is a characteristic loss of von Willebrand factor high molecular weight multimers. In vitro, the soluble interaction of normal von Willebrand factor with platelets can be initiated with exogenous modulators, the most common being the antibiotic ristocetin. The variant molecules resulting in type 2B von Willebrand disease can sustain binding to platelets at subnormal levels of ristocetin. We characterized the von Willebrand factor gene of an individual with type 2B von Willebrand disease and identified a nucleotide transition resulting in an Arg543-->Trp amino-acid substitution within the GP Ib-IX binding domain of von Willebrand factor. In this study we demonstrate that a recombinant plasmid capable of expressing the isolated GP Ib-IX binding domain of von Willebrand factor, and containing the Arg543-->Trp amino-acid substitution, secretes a dimeric molecule that supports platelet agglutination using subnormal levels of ristocetin. These results demonstrate that the mutation at position 543 increases the affinity between the variant molecule and platelet GP Ib-IX as an intrinsic feature of the isolated von Willebrand factor domain. Thus, structural perturbations within the GP Ib-IX binding domain that are independent of the von Willebrand factor multimeric structure can sufficiently increase the affinity of von Willebrand factor to sustain platelet aggregation, using subnormal levels of ristocetin.

Small increase in triplet repeat length of cerebellum from patients with myotonic dystrophy

Myotonic dystrophy (DM) is genetically characterized by abnormal expansion of an unstable CTG trinucleotide repeat, located in the 3'-untranslated region of mRNA encoding the family of serine-threonine protein kinases. DNA extracted from various organs of patients with DM was analyzed by the Southern blotting method. We identified differently expanded bands in DNAs from various tissues from patients with DM. In studying the length of the CTG repeat in different regions of the brain, we found a noticeably small increase in repeat length in the cerebellum compared with other tissues. While this phenomenon has been reported in other triplet repeat diseases such as Huntington disease, spinocerebellar ataxia type 1, and dentatorubral-pallidoluysian atrophy, we are the first to describe it in DM. Although the mechanism of expansion of the triplet repeat remains to be defined, the tissue-dependent somatic mosaicism suggests that its occurrence may depend on the differentiated state of each tissue.

Cloning of mouse prolidase cDNA: predominant expression of prolidase mRNA in kidney

We cloned mouse prolidase cDNA from a mouse liver cDNA library. Homology to human prolidase is 83.2% at the nucleotide level and 87.2% at the amino acid level. Northern blot analysis showed that while prolidase mRNA was transcribed in brain, heart, liver, and muscle, it was predominantly transcribed in kidney.

Heparin cofactor II-dependent antithrombin activity of calcium spirulan

Calcium spirulan (Ca-SP), a novel sulfated polysaccharide isolated from the blue-green alga Spirulina platensis, enhanced the antithrombin activity of heparin cofactor II (HC II) more than 10000-fold. The apparent second-order rate constant of thrombin inhibition by HC II was calculated to be 4.2 x 10(4) M-1 min-1 in the absence of Ca-SP, and it increased in the presence of 50 micrograms/ml Ca-SP to 4.5 x 10(8) M-1 min-1. Ca-SP effectively induced the formation of a thrombin-HC II complex in plasma. In the presence of Ca-SP, both the recombinant HC II variants Lys173-->Leu and Arg 189-->His, which are defective in interactions with heparin and dermatan sulfate, respectively, inhibited thrombin in a manner similar to native rHC II. This result indicates that the binding site of HC II for Ca-SP is different from the heparin- or dermatan sulfate-binding site. When we removed the calcium from the Ca-SP, the compound did not exert any antithrombin activity. Furthermore, Na-SP, which was prepared by replacement of the calcium in Ca-SP with sodium, accelerated the antithrombin activity of HC II as Ca-SP did. We therefore suggest that the molecular conformation maintained by Ca or Na is indispensable to the antithrombin activity of Ca-SP. The HC II-dependent antithrombin activity of Ca-SP was almost totally abolished by treatment with chondroitinase AC I, heparinase or heparitinase, but not by treatment with chondroitinase ABC and chondroitinase AC II, suggesting that a heparin- or dermatan sulfate-like structure is not responsible for the activation of HC II by Ca-SP. Ca-SP is therefore thought to be a unique sulfated polysaccharide which shows a strong antithrombin effect in an exclusively HC II-dependent manner.

Inhibitory effect of a synthetic prostacyclin analogue, beraprost, on urokinase-type plasminogen activator expression in RC-K8 human lymphoma cells

Plasminogen activation by urokinase-type plasminogen activator (uPA) is implicated in tumor invasion and metastasis by the breakdown of extracellular matrix. We have recently demonstrated the inhibitory effect of cAMP on uPA gene transcription in RC-K8 human lymphoma cells (Biochim Biophys Acta 1268: 293-9, 1995). Prostacyclin produced by endothelial cells is shown to increase cellular cAMP levels by activating adenylate cyclase. We, therefore, examined the effect of a stable analogue of prostacyclin, Beraprost, on uPA production in RC-K8 cells. uPA activity gradually increased in the conditioned medium with time. Beraprost (0.1 nM-1.0 microM) inhibited uPA accumulation in a dose-dependent manner without affecting cell viability. Fibrinzymography demonstrated that high and low molecular forms of uPA were present in the conditioned medium and that after Beraprost-treatment all forms of uPA decreased and no PA/PA inhibitor complex was present. Northern blot analysis revealed that after exposure to Beraprost, uPA mRNA levels increased transiently and then rapidly decreased to below control levels. Treatment with Beraprost resulted in a rapid activation of cellular cyclic AMP-dependent protein kinase (PKA). Beraprost completely negated uPA gene expression induced by phorbol myristate acetate, an activator of protein kinase C (PKC). These results suggest that Beraprost inhibits uPA production by suppressing uPA gene expression through the PKA pathway and that PKA-mediated signals are dominant in uPA gene expression as compared to those medicated by PKC. This inhibition of uPA expression by a prostacyclin analogue may be an important fact to explain the mechanism of anti-metastatic effects of prostacyclin.

Expression of markers for both neuronal and glial cells in human amniotic epithelial cells

Human amniotic epithelial (HAE) cells are formed from amnioblasts, separated from the epiblast at about the 8th day after fertilization. We attempted to detect various developmental antigens specific to neural cells by immunocytochemical methods. The cultured HAE cells displayed positive immunoreactivity to RC1, vimentin, A2B5, neurofilament proteins, microtubule-associated protein 2 (MAP2) and MAP2 kinase. In addition, the cells also demonstrated immunoreactivity to glial fibrillary acidic protein, CNPase, myelin basic protein and galactocerebroside. The appearance rate of positive cells was more than 50% in cells positive to RC1, A2B5, vimentin or neuronal markers, and 20-30% to glial cell markers. Double staining showed the heterogeneous appearance of oligodendrocyte lineage cells. These data indicate that HAE cells may have the putative multipotentiality of neurons, astrocytes and oligodendrocytes.

Acid alpha-glucosidase deficiency: identification and expression of a missense mutation (S529V) in a Japanese adult phenotype

We report a missense mutation in an adult Japanese patient with acid alpha-glucosidase (GAA) deficiency. A TC to GT transition at nucleotides 1585-1586, was identified. This transition resulted in an amino acid substitution of Ser-529 to Val (S529V) in exon 11. We also have demonstrated that the S529V mutation abolishes the catalytic activity of the enzyme. Our data suggest that this mutation is the cause of the clinical manifestation known as adult-onset GAA deficiency. The missense mutation described here is a new mutation, and the first identified in Japanese patients with GAA deficiency.

A deletion of five nucleotides in the L1CAM gene in a Japanese family with X-linked hydrocephalus

X-linked hydrocephalus (HSAS) is the most common form of inherited hydrocephalus characterized by hydrocephalus due to stenosis of the aqueduct of Sylvius, mental retardation, clasped thumbs, and spastic paraparesis. MASA syndrome (mental retardation, aphasia, shuffling gait and adducted thumbs) and SPG1 (X-linked complicated spastic paraplegia) are also X-linked disorders with overlapping clinical signs. Linkage analysis studies implicated the neural cell adhesion molecule L1 (L1CAM) gene as a candidate gene for these X-linked disorders. This genetic study analyzes the L1CAM gene in a Japanese family with members suffering from HSAS, and describes a deletion of five nucleotides in exon 8. Screening by Bg1I digestion of polymerase chain reaction (PCR) products revealed that two siblings have the same mutation and a sister was identified as a heterozygous carrier. The 5 nucleotide deletion causes a shift of the reading frame and introduces a premature stop codon 72 nucleotides downstream, which might result in a truncated protein. The mutation identified herein is a novel L1CAM mutation, which triggers hydrocephalus. We report a unique L1CAM mutation that causes HSAS: the first report of such a mutation in a Japanese family.

[A family with X-linked hydrocephalus resulting from mutations in the neural cell adhesion molecule L1]

We present the two siblings with X-linked hydrocephalus (XLH) and discuss the clinical features and genetical analysis of them. Case 1. The proband, a male, was delivered by the emergency cesarean section because of enlarged head circumference (44cm). His head circumference at 24 years old was 92cm. Neurological examination revealed adducted thumbs, horizontal nystagmus, hyperreflexia and spasticity of legs. He had tonic convulsions. MRI revealed a very thin layer of cerebral cortex. Molecular analysis revealed a deletion of 5 bases in exon 8 of the cell adhesion molecule L1 (L1CAM) gene located at chromosome Xq28. Case 2. The younger maternal half brother of case 1 was also born by the cesarean section, with 48cm in head circumference. A ventriculoatrial shunt was placed at the first month old. Epileptic seizures were seen. At the age of 21 years he had a head circumference of 59cm. A physical examination showed bilateral adducted thumbs, upward deviation of eyes, hyperreflexia and spasticity of legs. CT showed marked generalized ventricular enlargement including the fourth ventricle. Molecular analysis confirmed the same mutations as that of case 1. A maternal uncle had a previous diagnosis of hydrocephalus, and a sister is identified as a heterozygous carrier from molecular genetical analysis. Our results indicate that HLX is caused by the mutations in the gene for neural L1CAM in our family.

The production of heparin cofactor II is not regulated by inflammatory cytokines in human hepatoma cells: comparison with plasminogen activator inhibitor type-1

Using the Northern blot technique, we screened 6 human hepatoma cell lines to investigate the regulation mechanism of heparin cofactor II (HC II) biosynthesis. We found that HuH-7 and Hep G2 cells constitutively expressed the HC II gene. In conditioned medium, HuH-7 cells constantly produced HC II that was functionally active and formed a complex with thrombin in the presence of dermatan sulfate. HC II is thought be an acute phase reactant, and, therefore, we examined the effects of the major inflammatory cytokines, IL-6, IL-1 beta, and TNF-alpha, on the regulation of HC II production in HuH-7 and Hep G2 cells. In HuH-7 cells, the antigen and mRNA levels of plasminogen activator inhibitor type-1 (PAI-1), an acute phase protein produced by hepatocytes, were increased in response to stimulation with either IL-6 or IL-1 beta or both, but HC II antigen and mRNA levels were not changed by the same stimulation. Even when Hep G2 cells were treated with a combination of three cytokines, IL-6, IL-1 beta, and TNF-alpha, HC II antigen and mRNA levels were not changed; however, PAI-1 antigen and mRNA levels were clearly increased. These results suggest that the production of HC II in hepatoma cells is not regulated by the major inflammatory mediators, IL-6, IL-1 beta, and TNF-alpha.

Effects of low molecular weight heparin on a severely antithrombin III-decreased disseminated intravascular coagulation model in rabbits

The effect of dalteparin, a low molecular weight heparin, on severely antithrombin III (ATIII)-decreased disseminated intravascular coagulation (DIC) model was compared with that of unfractionated heparin (heparin). The DIC model in rabbits was produced by continuous infusion of thrombin in combination with bolus injection of latex. After a 3 hr infusion of thrombin, plasma ATIII activity was lowered to 30% of normal plasma. Platelet number, fibrinogen content and alpha 2 plasmin inhibitor (alpha 2PI) activity were also decreased. Dalteparin (25-100 IU/kg/hr) and heparin (25-100 U/kg/hr) inhibited the decrease in ATIII activity, platelet number and fibrinogen content, and had no effect on alpha 2PI activity. Activated partial thromboplastin time (APTT) was prolonged by heparin (50 and 100 U/kg/hr), but not by dalteparin (25-100 IU/kg/hr). The ratio of anti-factor Xa (F.Xa) activity to anti-thrombin activity for dalteparin (50 IU/kg/hr) was higher than that for heparin (50 U/kg/hr). With the addition of exogenous ATIII, the ratio of anti-F.Xa to anti-thrombin for heparin increased, but that for dalteparin did not change. However, the increased ratio for heparin was still lower than the unchanged ratio for dalteparin. These results suggest that both dalteparin and heparin have the ability to rectify the abnormal parameters of severely ATIII-decreased DIC, and that the effects of dalteparin are mainly involved with anti-F.Xa activity whereas the effects of heparin are via anti-thrombin activity.

[Medicinal therapy for lysosomal storage diseases]

Lysosomes contain several dozen different enzymes, mostly acid hydrolases. Materials not digested due to deficient lysosomal enzymes are usually large cellular molecules, which are deposited within the cells. The strategy for medicinal therapy of lysosomal storages disease may be to develop the activators of enzymes, to promote coenzyme and cofactor supplementation and to eliminate undegraded materials from blood into urine. In the last several decades, many trials for these strategies has been done. Cysteamine for cystinosis and penicillamine for Wilson's disease has proved useful in treating these patients. Recently, DMSO has been proved to be an activator of acid sphingomyelinase and to accelerate the intracellular mobilization of LDL-derived cholesterol. We treated patients with Niemann-Pick disease type C by oral administration of DMSO, resulting in some clinical benefits such as decreased size of hepatosplenomegaly, and lesser frequency of seizures with improved EEG. However, the progressive clinical course has not been changed although it appeared to slow down. New activators of lysosomal enzymes should be developed for medicinal therapy of lysosomal storage diseases.

Modulation of urokinase-type plasminogen activator gene expression by inflammatory cytokines in human pre-B lymphoma cell line RC-K8

We examined the effects of inflammatory cytokines, such as interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF alpha), transforming growth factor-beta (TGF beta) and lipopolysaccharide (LPS), on the urokinase-type plasminogen activator (uPA) gene expression in RC-K8 human pre-B lymphoma cells. Recombinant IL-1 alpha, recombinant IL-1 beta and LPS but not recombinant IL-6, recombinant TNF alpha and TGF beta dose-dependently increased uPA accumulation in the conditioned medium. Northern blot analysis revealed that uPA mRNA levels rapidly increased with a peak induction at 2 h after stimulation with IL-1 alpha and IL- 1 beta, but uPA mRNA increase by LPS began at 9 h after stimulation and the increase was maintained until the experiment ended at 24 h. These responses were independent of de novo synthesis, rather amplified in the presence of a protein synthesis inhibitor. The effects by IL-1 alpha and Il-1 beta were prevented by addition of anti-IL-1 alpha and anti-IL-1 beta neutralizing antibodies, respectively. In contrast, both antibodies did not prevent LPS-induced uPA gene expression. Therefore, it is unlikely that the effect by LPS is through induction of IL-1. Both IL-1 alpha and IL- 1 beta rapidly activated uPA gene transcription, but not increased stability of uPA mRNA. These results suggest that both IL-1 alpha and IL-1 beta cause a rapid activation of uPA gene transcription in which de novo protein synthesis is not required and that LPS induces uPA gene expression independently of the IL-1 pathway. These modulations of uPA production by inflammatory mediators may be implicated in tumor growth and metastasis.

Identification and expression of a missense mutation (Y446C) in the acid sphingomyelinase gene from a Japanese patient with type A Niemann-Pick disease

Types A and B Niemann-Pick disease (NPD), an autosomal recessive lysosomal storage disorder, are caused by deficiency of acid sphingomyelinase (ASM). The recent identification of mutations in ASM gene causing types A and B NPD has led to the investigation of the phenotypic heterogeneity and the ethnic distribution of this disease, especially in Ashkenazi Jewish population. To characterize the mutations causing NPD in Japanese population, we analyzed the genomic sequence of ASM from a Japanese patient with type A NPD by PCR amplification and sequencing. A new mutation, Y446C, was identified. The authenticity of this lesion was demonstrated by the expression of the Y446C allele in COS-1 cells. No residual ASM activity was detected from the expression of the Y446C.

Selective activation of heparin cofactor II by a sulfated polysaccharide isolated from the leaves of Artemisia princeps

While checking anticoagulant activities in crude fractions from Wakan-Yakus (traditional herbal drugs), we detected antithrombin activity in the polysaccharide fraction of the leaves of Artemisia princeps Pamp. A sulfated polysaccharide purified from the crude fractions by ion-exchange chromatography on DEAE-cellulose and gel filtration on Sepharose 6B potentiated the heparin cofactor II (HC II)-dependent antithrombin activity but not the antithrombin activity of antithrombin III (AT III). The polysaccharide enhanced the HC II-thrombin reaction more than 6000-fold. The apparent second-order rate constant of thrombin inhibition by HC II increased from 3.8 x 10(4) (in the absence of the polysaccharide) to 2.5 x 10(8) M-1 min-1 in the presence of 25-125 micrograms/ml of the polysaccharide. In human plasma, the polysaccharide accelerated the formation of thrombin-HC II complex. The stimulating effect on HC II-dependent antithrombin activity was almost totally abolished by treatment with chondroitinase AC I, heparinase or heparitinase, while chondroitinase ABC or chondroitinase AC II had little or no effect. These results suggest that the polysaccharide is a glycosaminoglycan-like material with properties that are quite distinct from heparin or dermatan sulfate.