9-Cis-retinoic acid exhibits antifibrotic activity via the induction of cyclooxygenase-2 expression and prostaglandin E2 production in scleroderma fibroblasts.

BACKGROUND: The pathogenesis of scleroderma (SSc) is not fully understood, and there is no effective treatment for this chronic disease. Retinoic acid (RA) can modulate connective tissue metabolism, exhibit antifibrotic activity and improve the clinical symptoms of patients with SSc. However, the mechanisms by which RA elicits its antifibrotic actions remain to be determined. OBJECTIVE: To elucidate the underlying mechanisms by which retinoids exert beneficial effects on SSc. METHODS: Cultured skin fibroblasts from patients with SSc were treated with retinoids (9-cis-, 13-cis- and all-trans-retinoic acid) and their effect on the expression of cyclooxygenase (COX)-2, connective tissue growth factor (CTGF) and type I and III collagen and on the production of PGE(2) was examined. COX-2 expression was analysed by western immunoblotting, PGE(2) production by enzyme immunoassay and CTGF expression, and type I and III collagen expression by reverse transcriptase PCR and western immunoblotting. RESULTS: In cultured SSc fibroblasts, 9-cis-RA significantly increased COX-2 protein expression and PGE(2) production and inhibited the expression of CTGF and type I and III collagen. We further found that expression of CTGF and of type I and III collagen mRNA was inhibited by exogenous PGE(2) in SSc fibroblasts. CONCLUSION: In vitro, 9-cis-RA induced COX-2 expression and PGE(2) production in SSc fibroblasts and PGE(2) downregulated CTGF expression, leading to the inhibition of type I and III collagen synthesis. Our results indicate that the clinical effects of 9-cis-RA on SSc are, at least in part, attributable to the induction of PGE(2) and the subsequent suppression of CTGF expression that results in the blockade of collagenogenesis.

Selective expression of the tba-1 alpha tubulin gene in a set of mechanosensory and motor neurons during the development of Caenorhabditis elegans.

In the nematode Caenorhabditis elegans, a monoclonal antibody 3A5 raised against Drosophila alpha tubulins selectively stains the nervous system immuno-cytochemically. Direct screening of a C. elegans cDNA expression library with 3A5 has allowed cloning of the tba-1 (tubulin alpha-1) gene from C. elegans. The corresponding genomic DNA encodes a protein of 449 amino acid residues that has a high homology with the vertebrate alpha tubulins but a lower homology with yeast alpha tubulins. Interestingly, the carboxyl-terminus sequence EEEGEEY (Glu-Glu-Glu-Gly-Glu-Glu-Tyr) of the nematode tba-1 encoded isotype is identical to these residues in human, mouse, rat, pig and chicken alpha-1 tubulin isotypes that are expressed in the brain. Temporal and spatial expression studies of the tba-1 gene using Northern blot analysis and tba-1::lacZ fusion gene expression analysis during embryonic and the postembryonic development of C. elegans reveal that the tba-1 tubulin is preferentially expressed in the nematode nervous system, especially in a set of mechanosensory neurons and a set of ventral cord motor neurons (DA, DB, VA, and VB) during embryonic and postembryonic development. Our results indicate an inter-species conservation of the alpha tubulin carboxyl-terminal domain in functionally related brain specific isotypes from metazoans as divergent as mammals and nematodes. These results also suggest specificity of the individual alpha tubulin isotypes during neural development.

Aberrations of ammonia metabolism in ornithine carbamoyltransferase-deficient spf-ash mice and their prevention by treatment with urea cycle intermediate amino acids and an ornithine aminotransferase inactivator.

Sparse fur with abnormal skin and hair (spf-ash) mice are deficient in ornithine carbamoyltransferase (OCT) activity, but their OCT protein is kinetically normal. We administered ammonium chloride to spf-ash mice, in order to analyze ammonia metabolism and to find a rationale for the therapy of OCT deficiency. Ammonia concentration in the liver of spf-ash mice increased to a level much higher than in the control. Ammonium chloride injection caused an increase in ornithine (Orn) 5 min after injection and an increase in the sum of Orn, citrulline (Cit) and arginine (Arg) for at least 15 min in the liver of control mice, but no increase in Orn, Cit and Arg in the liver of spf-ash mice. Treatment of spf-ash mice with Arg 5-20 min prior to the injection of ammonium chloride kept the hepatic ammonia concentration at a level comparable to that without the load. A significant reciprocal relationship between ammonia and Orn concentrations in the liver of spf-ash mice 5 min after an ammonium chloride load with or without Arg strongly suggests that ammonia disposal is dependent on the supply of Orn. In spf-ash mice loaded with tryptone as a nitrogen source, Arg supplementation showed a dramatic decrease in urinary orotic acid excretion in a dose-dependent manner. Similar effects were observed with Cit and Orn at the same dose, and a long-lasting effect with an ornithine aminotransferase inactivator, 5-(fluoromethyl)ornithine, at a much lower dose. The rate of urea formation in liver perfused with ammonium chloride was lower in spf-ash mice than in controls, but with the addition of Orn to the medium it increased to a similar level in control and spf-ash mice. These results indicate that OCT is not saturated with Orn in vivo under physiological conditions and that the administration or enrichment of the urea cycle intermediate amino acids enhances the OCT reaction so that the ammonia metabolism of OCT-deficient spf-ash mice is at least partially normalized.

Molecular cloning and developmental expression of the alpha-2 tubulin gene of Caenorhabditis elegans.

Alpha tubulin isotypes are encoded by at least four genes designated alpha-1 to alpha-4 in the nematode Caenorhabditis elegans. We describe here, molecular cloning of the alpha-2 tubulin gene, located on chromosome I, that encodes a protein of 449 amino acids that has high homology to human, mouse and Drosophila alpha tubulins, but relatively lower homology to the yeast alpha tubulins. The alpha-2 tubulin gene is trans-spliced to the SL1 leader sequence. Northern analysis shows that the gene is increasingly transcribed during the early (L1-L3) larval stages but has a lower level of transcription in L4 L4 larvae, adults, and embryos. Using an alpha-2-lacZ fusion gene expression in transgenic animals, we show that the gene is expressed in a tissue-specific manner in the intestine, pharyngeal muscle cells, and a subset of neurons which include a class of DB and VB motor neurons in the ventral nerve cord, posterior touch receptor neurons, PLML, PLMR, in the lumbar ganglia; PVT in the pre-anal ganglion, and ALA in the dorsal ganglion in the head. Our results support the notion that tubulin structure may contribute to the functional specialization of microtubules.

Serum calcium-decreasing factor (caldecrin) from porcine pancreas has proteolytic activity which has no clear connection with the calcium decrease.

We purified a serum calcium-decreasing factor, which showed chymotrypsin-like protease activity, from porcine pancreas to homogeneity. The factor administered to mice intravenously at a dose of 20 micrograms/kg b.w. decreased serum calcium by 15%. Treatment of the factor with the serine protease inhibitor, PMSF, caused a leftward shift in the dose-response curve, showing strengthened activity. It also caused a decrease in serum calcium and hydroxyproline levels in rats. At a dose of 10 ng/ml, the factor inhibited 45Ca release from cultured fetal long bone stimulated by parathyroid hormone (PTH) and PTH-related protein, but not by interleukin-1 alpha, prostaglandin E1 and 1,25-dihydroxy vitamin D3. No other well-known pancreatic proteases had these effects. In view of the results of experiments using protease inhibitor and pancreatic proteases, and in view of the specificity of this factor in vitro, we propose that the factor exerts its serum calcium-decreasing activity most probably not through proteolytic degradation of PTH, but through an inhibition of PTH action on bones by a yet undefined mechanism.

Caldecrin proform requires trypsin activation for the acquisition of serum calcium-decreasing activity.

Proform serum calcium-decreasing factor (procaldecrin) was purified from porcine pancreas acetone powder. Procaldecrin showed chymotrypsin activity after trypsin treatment in a time- and dose-dependent manner. Procaldecrin did not possess serum calcium-decreasing activity but acquired serum calcium-decreasing activity as well as protease activity after trypsin treatment. However, PMSF treatment after activation of procaldecrin by trypsin did not affect the serum calcium-decreasing activity, even though protease activity was nullified by treatment with PMSF. These findings suggest that the serum calcium-decreasing activity acquired by procaldecrin requires conformational change caused by trypsin treatment.

Face immersion in cold water induces prolongation of the QT interval and T-wave changes in children with nonfamilial long QT syndrome.

We investigated the relation between heart rate and the QT interval using face immersion in cold water in children with long QT syndrome (LQTS) without a family history of this condition, and in control children. The face immersion test revealed that all children with high probability of LQTS had a significantly longer QT interval than control children during face immersion, and that the test could induce T-wave alternans or a notched T-wave in all children with a high probability of LQTS.

Analyses of the transglutaminase 1 gene mutation and ultrastructural characteristics in a Japanese patient with lamellar ichthyosis.

We described a Japanese female with lamellar ichthyosis whose transglutaminase 1 gene (TGM1 gene) was mutated. DNA sequence analysis revealed that the patient had a homozygous mutation, i.e. a point mutation from G to A at nucleotide 1494 resulting in the substitution of glycine for arginine at codon 143. Her mother was heterozygous for this mutation. In situ transglutaminase assay in the patient's skin showed loss of enzyme activity. Ultrastructural examination revealed incomplete formation of cornified cell envelopes and electron-dense materials adjacent to plasma membranes. These results suggest that defective transglutaminase activity caused by homozygous TGM1 gene mutation (G143R) results in disruption of cornified envelope assembly and the clinical phenotype of lamellar ichthyosis.

C. elegans osm-3 gene mediating osmotic avoidance behaviour encodes a kinesin-like protein.

In the nematode Caenorhabditis elegans, mutants in osm-3 gene are known to be defective in osmotic avoidance, chemotaxis and dauer formation behaviours. To study the molecular basis of these pleiotropic defects we have cloned the osm-3 gene by germline transformation of osm-3 (p802) mutants through microinjection of the wild type genomic DNA. Northern analysis reveals a 3.0 kb transcript corresponding to osm-3. DNA sequencing of the transforming 4.3 kb fragment revealed a kinesin heavy chain-like protein, which contains conserved ATPase and microtubule binding domains. Our results are consistent with the previous EM data on osm-3 (p802) mutants that show an accumulation of dense matrix material in the amphid sheath cytoplasm and a shortened distal segment of the amphid channel cilium. These data suggest a kinesin-like role of the osm-3 product in axonal transport.

The expression of cadherins in human neuroblastoma cell lines and clinical tumors.

Cadherins are Ca(2+)-dependent cell-cell adhesion molecules which play crucial roles in the cell-cell interactions during development, tumorigenesis and metastasis. The absence of N (neural)-cadherin is correlated with the onset of neural crest migration and its reappearance is correlated with the cessation of migration and precedes gangliogenesis. We investigated the expression of cadherins including N-cadherin in five cell lines and eleven clinical specimens of human neuroblastomas, which originated from neural crest cells. We found that three of the neuroblastoma cell lines and all the clinical specimens were positive for the expression of the N-cadherin protein. The other two neuroblastoma cell lines were negative for the expression suggesting they originated from migrating neural crest cells. All these cell lines and clinical samples expressed either cadherin-6, cadherin-11 or both, i.e. cadherins expressed on neural crest cells, supporting their neural crest origin.

Pyruvate decarboxylase encoded by the PDC1 gene contributes, at least partially, to the decarboxylation of alpha-ketoisocaproate for isoamyl alcohol formation in Saccharomyces cerevisiae.

Isoamyl alcohol is an important flavor component of yeast-fermented alcoholic beverages. To identify the enzyme and gene involved in the decarboxylation of alpha-ketoisocaproate (alpha-KIC) for isoamyl alcohol formation, the enzyme was partially purified and analyzed by mass spectrometry. The pyruvate decarboxylase encoded by the PDC1 gene was considered a likely candidate enzyme. Genetic analysis showed that the activity of alpha-KIC decarboxylase and production of isoamyl alcohol partially decreased in a pdc1 null mutant and increased in a transformant with a multi-copy plasmid carrying the PDC1 gene. These results indicate that pyruvate decarboxylase encoded by the PDC1 gene contributes, at least partially, to the decarboxylation of alpha-KIC for isoamyl alcohol formation.

Different clonal drug sensitivity of murine neuroblastoma cells in vivo.

Four cloned murine neuroblastomas were implanted intramuscularly into the left thigh of adult A/Jax mice. Cyclophosphamide, cisplatin, adriamycin, imidazole carboxamide, and vincristine were administered intraperitoneally, in a dose of one third to one fourth of a median lethal dose, every week after the implantation until all the mice died. The effects of continuous long-term chemotherapy, particularly on clonal differences, were then assessed. Cyclophosphamide was most effective for four murine neuroblastomas, and cisplatin was the next most effective drug. Cisplatin was not effective in the NS-20 cell line, a cholinergic cloned neuroblastoma. The C 1300 cell line (wild type) was tolerant to adriamycin, imidazole carboxamide, and vincristine. The N-18 cell line (an inactive clone) exhibited tolerance of adriamycin and imidazole carboxamide. In the N1E-115 cell line, an adrenergic clone, tumor growth was inhibited by all the drugs given. We conclude from this study that drug sensitivity differs with the clone, and that there are clones resistant to each drug.

Appendiceal abscess mimicking infected urachal cyst in a child with intestinal malrotation.

An appendiceal abscess with intestinal malrotation can occur anywhere in the abdomen, not only in the right lower quadrant. We report a case presenting a midline mass of the lower abdomen whose computed tomography (CT) and ultrasonography (US) findings mimicked a urachal abscess. A retrospective review of CT findings led to the correct diagnosis by showing malposition of the ascending colon.

[Changes in epidural pressure during epidural injection].

To evaluate the change of epidural pressure when local anesthetic was injected into epidural space, we inserted three epidural catheters in 13 patients. Epidural catheters were inserted at Th8/9, Th10/11 and L3/4 intervertebral spaces, and 2% mepivacaine 10 ml was injected through Th10/11 or L3/4 catheter. The change of epidural pressure was recorded from three catheters. The elevation of pressure was largest in the injected catheter, but the pattern of elevation was similar in all three catheters. The results suggest that the elevation of epidural pressure occurs at the same time all over the epidural space when local anesthetic is injected.

[Intraoperative assessment by laser-Doppler skin blood flowmetry of the efficacy of endoscopic thoracic sympathectomy].

We have investigated whether laser-Doppler (L-D) skin blood flowmetry on the finger could be useful for an intraoperative assessment of the efficacy of endoscopic thoracic sympathectomy (ETS) under general anesthesia. Subjects were 5 young adults receiving ETS for palmar hyperhidrosis. ETS was performed with the patients in the semi-sitting position under one lung ventilation. A pair of LDF probes were placed on the palmar side of the both second fingers. Palmar hyperhidrosis disappeared after ETS in all cases, but compensatory hyperhidrosis developed in the back of the body and the thigh. After completion of ETS on one side, the L-D skin blood flow increased to 267.6 +/- 211.1% on the side of ETS, and it increased in 2 other cases and decreased on the contrary in 3 cases on the other side. After ETS on both sides the L-D skin blood flow increased to 265.0 +/- 185.9% on the side of initial ETS and to 211.4 +/- 172.8% on the side of subsequent ETS. The initial EST induced reflex vasoconstriction on the finger of both sides and also on the toe. Spontaneous fluctuation and reflex vasoconstriction of the skin blood flow were still observed, although the periodicity of spontaneous fluctuation between the right and the left finger was lost in some of the cases. An increase in L-D skin blood flow on the side of ongoing ETS is useful for intraoperative assessment of ETS.

Immunoelectron-microscopic detection of globotriaosylceramide accumulated in the skin of patients with Fabry disease.

BACKGROUND: Fabry disease is characterized by the systemic accumulation of glycosphingolipids, particularly in the lysosomes of vascular endothelial cells of most organs due to the deficient activity of alpha-galactosidase A. The major glycolipid accumulated in tissue is globotriaosylceramide (GL-3). To date, no direct detection of GL-3 by immunoelectron microscopy has been reported. OBJECTIVES: To examine whether GL-3 is accumulated exclusively in lysosomes of cutaneous cells using an anti-GL-3 monoclonal antibody (mAb) and immunoelectron microscopy. METHODS: Skin specimens from seven patients with Fabry disease were examined immunohistochemically by light and electron microscopy using an anti-GL-3 mAb. RESULTS: By light microscopy, the cytoplasm of vascular endothelial cells, eccrine gland cells, and perineurium was stained with mouse anti-GL-3 antibody. Electron microscopically, positive signals for GL-3 were limited to dilated lysosomes in the cytoplasm of endothelial cells, pericytes, eccrine gland cells, dermal fibroblasts and perineurium. CONCLUSIONS: Our results demonstrate that the cytoplasmic deposit in Fabry disease was GL-3 and the accumulated GL-3 was localized essentially to lysosomes.