Polar and antioxidant fraction of Plumbago europaea L., a spontaneous plant of Sardinia.

Secondary metabolite isolation and analysis of Plumbago europaea L. (Plumbaginaceae) is the aim of this work, which is included in a project of our groups on spontaneous and endemic Sardinian species. Plumbago europaea is the only specie of the genera that grows wild in Italy. Metabolites from leaves and roots of this specie were compared. Moreover, at present, literature on the phytochemical characterisation of P. europaea is poor. Plumbagin was isolated in both of the samples analysed, confirming its nature in the Plumbaginaceae family as chemotaxonomic marker of the Plumbaginae tribe. In this work, hydroplumbagin-4-O-glucoside and myricetin-3-O-rhamnoside are isolated for the first time in the genus.

Genetic and phytochemical difference between some Indian and Italian plants of Withania somnifera (L.) Dunal.

The geographical distribution of Withania somnifera (L.) Dunal is quite wide. However, in Italy, this species is very rare and grows spontaneously only in Sicily and in Sardinia. The PCR-RAPD technique has been utilized in this work to determine the genetic relationship among Sicilian, Sardinian and Indian samples and the HPLC analysis of whitaferin A was used as a marker to evaluate the phytochemical differences. The genetic difference between Indian and Sicilian plants of W. somnifera turned out to be smaller than that between Indian and Sardinian plants of this species. The phytochemical analysis as well showed that the Sardinian specimen strongly differed from the Indian and Sicilian ones in its contents of withaferin A. Our results seem to confirm the hypothesis that the Italian populations of this species may not be indigenous but naturalised. Due to the high withaferin A content of the Sardinian samples, these plants could be used as a source for pharmaceutical purposes.

Vitamin C content and antioxidant activity of the fruit and of the Ayurvedic preparation of Emblica officinalis Gaertn.

Emblica officinalis Gaertn. is one of the most important plants of Ayurved, the traditional Indian medicine. In this ancient medicine, the fruit of Emblica officinalis is processed according to a method named "Svaras Bhavana", whereby the therapeutic potential of the plant is enhanced by treating the main herb with its own juice. For many years, the activity of the fruits was attributed to the high content of ascorbic acid; however, this has recently been questioned. The aim of the paper is to clarify this matter. A reliable and feasible HPLC method with diode array detection has been developed for the determination of ascorbic acid in Emblica fruit and particularly in Emblica fruit processed according to the Ayurvedic method. The antioxidant effects have also been evaluated in comparison to the real levels of Vitamin C by different antioxidant tests. The data obtained show that the Emblica fruit contains ascorbic acid (0.4%, w/w), and that the Ayurvedic method of processing increases the healthy characteristics of the fruit thanks to a higher antioxidant activity and a higher content of ascorbic acid (1.28%, w/w). It has also been found that Vitamin C accounts for approximately 45-70% of the antioxidant activity.

A novel human homologue of the SH3BGR gene encodes a small protein similar to Glutaredoxin 1 of Escherichia coli.

Glutaredoxins (GRXs) are ubiquitous GSH-dependent oxidoreductases, which catalyze the reduction of protein-glutathionyl-mixed disulfides and are considered to play an important role in the enzymatic regulation of redox-sensitive proteins. In this paper, we describe the identification and characterization of a new human homologue of the SH3BGR gene, named SH3BGRL3 (SH3 domain binding glutamic acid-rich protein like 3). SH3BGRL3 is widely expressed and codes for a highly conserved small protein, which shows a significant similarity to Glutaredoxin 1 (GRX1) of Escherichia coli and is predicted to belong to the Thioredoxin Superfamily. However, the SH3BGRL3 protein lacks both the conserved cysteine residues, which characterize the enzymatic active site of GRX. This structural feature raises the possibility that SH3BGRL3 could function as an endogenous modulator of GRX biological activity. EGFP-SH3BGRL3 fusion protein expressed in COS-7 cells localizes both to the nucleus and to the cytoplasm. The SH3BGRL3 gene was mapped to chromosome 1p34.3-35.

Review on some plants of Indian traditional medicine with antioxidant activity.

A lot of medicinal plants, traditionally used for thousands of years, are present in a group of herbal preparations of the Indian traditional health care system (Ayurveda) named Rasayana proposed for their interesting antioxidant activities. Among the medicinal plants used in ayurvedic Rasayana for their therapeutic action, some of these have been throughly investigated. In the present paper seven plants (Emblica officinalis L., Curcuma longa L., Mangifera indica L., Momordica charantia L., Santalum album L., Swertia chirata Buch-Ham, Withania somnifera (L.) Dunal) are viewed for their historical, etymological, morphological, phytochemical and pharmacological aspects. The plants described contain antioxidant principles, that can explain and justify their use in traditional medicine in the past as well as the present. In order to identify the plants with antioxidant activity in Ayurveda, a formulation of some rasayanas with well defined antioxidant properties has been examinated. For this purpose, we have considered Sharma's work on the preparation MAK4, MAK5, MA631, MA 471, MA Raja's Cup, MA Student Rasayana, MA Ladies Rasayana.

Developmental expression of the SH3BGR gene, mapping to the Down syndrome heart critical region.

The SH3BGR gene has been recently isolated and mapped to chromosome 21 within the Down syndrome (DS) congenital heart disease (CHD) minimal region. As a first step to evaluate the possible involvement of SH3BGR in CHD that affect 40% of DS patients, we have analyzed by in situ hybridization the expression pattern of the mouse homolog gene (Sh3bgr), during development. Our results show that Sh3bgr is already expressed at embryonic day 7.75 (E7.75) in the precardiogenic mesoderm and that from E8.5 to E10.5 its expression is restricted to the heart. In subsequent developmental stages, Sh3bgr transcripts are also detected in skeletal muscle and in some visceral smooth muscles including urinary bladder and gut wall, but not in vascular smooth muscle. Our results, demonstrating that Sh3bgr is expressed in earliest stages of mouse heart development, support a possible role of this gene in heart morphogenesis and, consequently, in the pathogenesis of CHD in DS.

Identification and characterization of a new gene from human chromosome 21 between markers D21S343 and D21S268 encoding a leucine-rich protein.

We initiated the present work as part of an effort to identify and characterize genes from the EST2-HMG14 region from human chromosome 21 potentially responsible for some of the Down syndrome (DS) features. Genomic sample sequencing with cosmid clone A1047 located in the ETS2-HMG14 region of chromosome 21 has led to the identification and sequencing of a novel 1080-bp cDNA. This cDNA contains a potential ORF of 867 bp predicting a 288-amino-acid protein rich in leucine with a molecular weight of 32.8 kD. Northern blot analysis and RT-PRC indicate that the expression of this novel gene is high in testis and in the human leukemic T cell line Jurkat and lower in other tissues including all fetal tissues studied. We have called to this novel gene c21-LRP (chromosome 21 leucine-rich protein) and, because of its location in the DS-2 region, it could be a candidate for some of the DS anomalies. Mapping experiments have narrowed the location of the c21-LRP gene between markers D21S343 and D21S268 from chromosome 21. Analysis of the c21-LRP protein predicts two transmembrane helices and detects several signatures and potential homologies to known proteins pointing toward several potential roles for this protein.

Identification and characterization of a new human gene encoding a small protein with high homology to the proline-rich region of the SH3BGR gene.

As part of an effort to identify genes potentially involved in the Down Syndrome pathogenesis, in this paper we report the identification and characterization of a new human gene (named SH3BGRL), which shows a high homology to the SH3BGR gene, previously mapped to the Down Syndrome region of chromosome 21. The SH3BGRL gene encodes for a small protein of 114 amino acids, sharing 60% identity and 84% conservation on the amino acid level with the middle, proline-rich region of the SH3BGR gene and containing a similar SH3 (Scr homology 3) binding motif. The SH3BGRL and the proline-rich region of SH3BGR proteins appear to be highly conserved, sharing 95 and 98% identity, respectively, with the mouse homologues. A 1.9 kb transcript of the SH3BGRL gene has been found in all the tissues examined, in contrast with the expression pattern of the SH3BGR gene which is transcribed only in heart and skeletal muscle. The SH3BGR gene and its homologue, SH3BGRL, could be members of a new family of genes containing a highly conserved proline-rich functional domain. The SH3BGRL gene has been mapped by fluorescent in situ hybridization to Chromosome Xq13.3.

Mutations in the caveolin-3 gene cause autosomal dominant limb-girdle muscular dystrophy.

Limb-girdle muscular dystrophy (LGMD) is a clinically and genetically heterogeneous group of myopathies, including autosomal dominant and recessive forms. To date, two autosomal dominant forms have been recognized: LGMD1A, linked to chromosome 5q, and LGMD1B, associated with cardiac defects and linked to chromosome 1q11-21. Here we describe eight patients from two different families with a new form of autosomal dominant LGMD, which we propose to call LGMD1C, associated with a severe deficiency of caveolin-3 in muscle fibres. Caveolin-3 (or M-caveolin) is the muscle-specific form of the caveolin protein family, which also includes caveolin-1 and -2. Caveolins are the principal protein components of caveolae (50-100 nm invaginations found in most cell types) which represent appendages or sub-compartments of plasma membranes. We localized the human caveolin-3 gene (CAV3) to chromosome 3p25 and identified two mutations in the gene: a missense mutation in the membrane-spanning region and a micro-deletion in the scaffolding domain. These mutations may interfere with caveolin-3 oligomerization and disrupt caveolae formation at the muscle cell plasma membrane.

Identification and characterization of a new human cDNA from chromosome 21q22.3 encoding a basic nuclear protein.

Congenital heart disease (CHD) affects over 40% of Down syndrome (DS) patients. The region proposed to contain the gene(s) for DS CHD has been restricted to 21q22.2-22.3, from D21S55 to MX1. The identification and functional characterization of the genes mapping to this region is a necessary step to understand the pathogenesis of CHD in DS. In an effort to contribute to the construction of a transcriptional map of the DS CHD region we have performed direct cDNA selection using a YAC contig that maps between ETS2 and D21S15 and cDNAs synthesised from fetal heart structures. Here we describe the identification and characterization of a new gene, WRB, that maps to 21q22.3 between ACTL5 and HMG 14 and appears to be widely expressed in adult and fetal tissues. The new gene encodes a basic protein of unknown function containing a tryptophan-rich carboxyl-terminal region and a potential nuclear localization signal. Immunofluorescence analysis shows a predominant localization in the cell nucleus. The understanding of the biological function of the protein product should clarify the potential role of WRB in the pathogenesis of DS CHD.

High resolution physical mapping and identification of transcribed sequences in the Down syndrome region-2.

The identification and mapping of genes within the Down syndrome region is an important step toward a complete understanding of the pathogenesis of this disorder. The objective of the present work is to identify and map genes within the Down syndrome region-2. Chromosome 21 cosmid clones corresponding to "cosmid pockets" 121-124 have been first used as a starting material for generation of a single high resolution integrated cosmid/PAC contig with full EcoRI/SmaI restriction map. The integrated contig has been further anchored to genetic and physical maps through the positioning of 6 markers in the following order: ACTL5-D21S3-684G2T7-D21S71-D21S343-D21S 268. The entire contig covers 342 kb of the Down syndrome region-2 of chromosome 21. Subsequently, we have isolated, identified, and mapped four novel cDNAs which we have named N143, N144, CHD/333, and 90/3H1 and a potentially transcribed genomic sequence (E05133T7). Additionally, we have accurately located a previously described gene, the WRB gene, between the markers ACTL5-D21S268 within this Down Syndrome Region-2.

Human NRD convertase: a highly conserved metalloendopeptidase expressed at specific sites during development and in adult tissues.

We report the cloning of the human homologue of the rat metalloprotease N-arginine dibasic convertase (NRD convertase). This endopeptidase is responsible for the processing, at the Arg-Lys dibasic site on the N-terminal side of the arginine residue, of propeptides and proproteins. Comparisons of the human and rat full-length cDNAs show similarity and identity of 94 and 91%, respectively. In humans NRD convertase is predominantly expressed in heart, skeletal muscle, and testis. We have also studied the expression of this gene in mouse at various developmental stages and found that the neural tissue is the almost exclusive site of expression in early development (between E 10.5 and E 16.5). To gain information about the possibility that defects in this gene are linked to inherited neuromuscular disorders, we determined the chromosomal location of the human NRD convertase gene by FISH analysis, showing that the gene resides at 1p32.2.

Cloning a new human gene from chromosome 21q22.3 encoding a glutamic acid-rich protein expressed in heart and skeletal muscle.

The identification and functional characterization of genes on chromosome 21 is a necessary step to understand the pathogenesis of the various phenotypic anomalies that affect Down syndrome patients. Using direct cDNA selection we have identified a new gene, SH3BGR, that maps to 21q22.3, proximal to HMG14, and is differentially expressed in heart and skeletal muscle. SH3BGR encodes a novel protein that is characterized by the presence of a proline-rich region containing the consensus sequence for a SH3-binding domain and by an acidic carboxyl-terminal region containing a glutamic acid-rich domain predicted to assume a coiled coil. The presence of two functional domains involved in protein-protein interactions suggests that SH3BGR could be part of a multimeric complex. Its overexpression might alter specific functions of muscular tissue and therefore take part in the pathophysiology of muscular hypotonia in Down syndrome.

High-resolution physical map and identification of potentially regulatory sequences of the human SH3BGR located in the Down syndrome chromosomal region.

We have isolated, mapped and sequenced the 5' promoter region of the human SH3BGR (SH3-Binding Glutamine Rich) gene located in the Down syndrome region-2, between markers D21S55 and MX1 of human chromosome 21. This region has been postulated as the minimal region for congenital heart disease and 6 facial and dermatoglyphic features present in Down syndrome. The SH3BGR gene is expressed in fetal and adult heart and in skeletal muscle and therefore it is a candidate gene for the congenital heart defect and muscle hypotonia. The 5' region of the gene has been positioned in a 115 kb PAC/cosmid contig with full EcoRI/SmaI restriction map covering cosmid pockets 122-123 as well as cosmid pocket 124 located between markers D21S268 and D21S220. Sequencing of the SH3BGR promoter region has allowed the identification of several potential regulatory elements of this candidate gene for the congenital heart disease and other potential DS features. Several of the elements identified are also present in other muscle-expressed genes.

Down syndrome and coeliac disease: usefulness of antigliadin and antiendomysium antibodies.

The usefulness of antigliadin (AGA) and antiendomysium antibodies (EMA) as a screening test for coeliac disease (CD) in 113 Down syndrome (DS) patients (61 children) was evaluated. AGA IgA were present in 22.1%, AGA IgG in 48.6%, EMA in 6.2%. Four symptomatic patients, AGA- and EMA-positive, were affected by CD (3.5%). In three AGA-positive and EMA-positive subjects, permission for intestinal biopsy was refused, while in two AGA-positive and EMA-negative children, the intestinal mucosa was normal. Our study confirms the association of CD and DS, and suggests the usefulness of EMA determination as a test for selecting DS patients for intestinal biopsy.

Presence of soluble amyloid beta-peptide precedes amyloid plaque formation in Down's syndrome.

Abnormal and excessive accumulation of the amyloid beta-peptide (A beta) in the brain is a major and common characteristic of all Alzheimer's disease (AD) forms irrespective of their genetic background. Insoluble aggregates of A beta are identified as amyloid plaques. These deposits are thought to form when the amount of A beta is increased in the brain parenchyma as a result of either overexpression or altered processing of the amyloid precursor protein (APP). Soluble A beta ending at carboxyl-terminal residue 40 (A beta 40) and, in lesser amount, the form ending at residue 42 (A beta 42), are normal products of the APP metabolism in cell cultures. Increased secretion of soluble A beta 42 has been observed in cells transfected with constructs modeling APP gene mutations of familial forms of AD (refs 4, 5). On the basis of these in vitro data it has been hypothesized that the presence of soluble A beta 42 plays a role in the formation of amyloid plaques. Subjects affected by Down's syndrome (DS) have an increased APP gene dosage and overexpress APP. Apparently because of this overexpression, they almost invariably develop amyloid deposits after the age of 30 years, although they are free of them at earlier ages. Moreover, it has been observed that A beta 42 precedes A beta 40 in the course of amyloid deposition in DS brain. Thus, DS subjects provide the opportunity to investigate in the human brain the metabolic conditions that precede the formation of the amyloid deposits. Here we report that soluble A beta 42 is present in the brains of DS-affected subjects aged from 21 gestational weeks to 61 years but it is undetectable in age-matched controls. It is argued that overexpression of APP leads specifically to A beta 42 increase and that the presence of the soluble A beta 42 is causally related to plaque formation in DS and, likely, in AD brains.

Incompletely processed N-glycans of serum glycoproteins in congenital dyserythropoietic anaemia type II (HEMPAS).

Congenital dyserythropoietic anaemia type II, or HEMPAS (hereditary erythroblastic multinuclearity with positive acidified serum lysis test) is a genetic disease caused by membrane disorganization of erythroid cells. The primary defect of this disease lies in the gene encoding enzyme(s) which is responsible for the biosynthesis of Asn-linked oligosaccharides chains of glycoproteins (Fukuda et al, 1990). In order to know whether this gene defect affects the glycosylation in the cells other than the erythroid cells, the carbohydrate structures of the transferrin isolated from the sera of HEMPAS patients were analysed. Fast atom bombardment mass spectrometry analysis showed the presence of high mannose type and hybrid type oligosaccharides in the HEMPAS transferrin which is in contrast to the complex-type oligosaccharides found in the normal transferrin. The results strongly suggest that biosynthesis of Asn-linked oligosaccharide chains in HEMPAS hepatocytes is disturbed. As a result, the serum glycoproteins with incompletely processed carbohydrates are circulating in the plasma in HEMPAS patients, but they must have been absorbed by the cells in the liver and the reticuloendothelial cells. Upon intravenous infusion into rats, as much as 30% of the HEMPAS transferrin was cleared from the plasma circulation. The majority of the HEMPAS transferrins was taken up by the liver, and transferrin was distributed both in the hepatocytes and the Kupffer cells. The presence of enormous amounts of aberrantly glycosylated serum glycoproteins may lead to the liver cirrhosis and secondary tissue siderosis seen in HEMPAS patients.

Expression of the human ETS-2 oncogene in normal fetal tissues and in the brain of a fetus with trisomy 21.

The expression of the ETS-2 proto-oncogene, located on chromosome 21, in normal fetal tissues and in neural tissue of a fetus affected by Down syndrome has been investigated. The results show that the ETS-2 proto-oncogene is expressed in almost all the tissues examined and that it is transcribed at constant levels in neural tissue between the 13th and 24th weeks. ETS-2 expression appeared to be slightly increased in Down syndrome brain compared with that of normal controls of the same gestational age.

Congenital dyserythropoietic anaemia type II (HEMPAS): characterization of aberrant intracellular organelles by immunogold electron microscopy.

Erythrocytes are reticulocytes obtained from peripheral blood of a congenital dyserythropoietic anaemia type II patient were examined by immunoelectron microscopy using anti-band 3 and anti-glycophorin A antibodies. Vacuoles which have membranous structures inside were stained heavily by these antibodies, indicating the presence of band 3 and glycophorin A in these vacuoles. Empty vacuoles which open to the cell surface and those present in cytoplasm were also stained by these antibodies at the inside of the wall. These observations suggest that the vacuoles are functioning for trapping and discarding the defective plasma membranes. On the other hand, small vesicles and ferritin-loaded vacuoles were not stained by these antibodies. In these experiments, peripheral cisternae and most of the intracellular membranous structures at blebs and clefts were not stained by the antibodies. Therefore, they are probably part of the endoplasmic reticulum or are derived from intracellular organelles but not from the plasma membranes.

Primary defect of congenital dyserythropoietic anemia type II. Failure in glycosylation of erythrocyte lactosaminoglycan proteins caused by lowered N-acetylglucosaminyltransferase II.

Congenital dyserythropoietic anemia type II or hereditary erythroblastic multinuclearity with positive acidified serum test (HEMPAS) is a genetic disease caused by membrane abnormality. Previously we have found that Band 3 and Band 4.5 are not glycosylated by lactosaminoglycans in HEMPAS erythrocytes, whereas normally these proteins have lactosaminoglycans (Fukuda, M. N., Papayannopoulou, T., Gordon-Smith, E. C., Rochant, H., and Testa, U. (1984) Br. J. Haematol. 56, 55-68). In order to find out where glycosylation of lactosaminoglycans stops, we have analyzed the carbohydrate structures of HEMPAS Band 3. By fast atom bombardment-mass spectrometry, methylation analysis, and hydrazinolysis followed by exoglycosidase treatments, the following structure was elucidated: (formula; see text) N-Linked glycopeptides synthesized in vitro by reticulocyte microsomes from HEMPAS were shown to be predominantly the above short oligosaccharide, whereas those from normal reticulocytes contain large molecular weight carbohydrates. The N-acetylglucosaminyltransferase II, which transfers N-acetylglucosamine to the C-2 position of the Man alpha 1----6Man beta 1----arm of the biantennary core structure, was therefore examined by using Man alpha 1----6(GlcNAc beta 1----2Man alpha 1----3)Man beta 1----4GlcNAc beta 1----4GlcNAcol as an acceptor. N-Acetylglucosaminyltransferase II activity was demonstrated in the lymphocyte microsome fraction from normal individuals. However, this enzyme activity was found to be decreased in those from HEMPAS patients. These results suggest that the primary defect of HEMPAS lies in the lowered activity of N-acetylglucosaminyltransferase II.