The evolution of ADAM gene family in eukaryotes

The ADAM (A Disintegrin And Metalloprotease) gene family encodes proteins with adhesion and proteolytic functions. ADAM proteins are associated with diseases like cancers. Twenty ADAM genes have been identified in humans. However, little is known about the evolution of the family. We analyzed the repertoire of ADAM genes in a vast number of eukaryotic genomes to clarify the main gene copy number expansions. For the first time, we provide compelling evidence that early-branching green algae (Mamiellophyceae) have ADAM genes, suggesting that they originated in the last common ancestor of eukaryotes, before the split of plants, fungi and animals. The ADAM family expanded in early metazoans, with the most significative gene expansion happening during the first steps of vertebrate evolution. We concluded that most of mammal ADAM diversity can be explained by gene duplications in early bone fish. Our data suggest that ADAM genes were lost early in green plant evolution.

Synthesis, structural characterization, cytotoxic properties and DNA binding of a dinuclear copper(II) complex

In this study a novel dinuclear copper(II) complex with adenine and phenanthroline has been synthesized and its structure determined by single crystal X-ray diffraction. In the dinuclear complex [Cu₂(μ-adenine)₂(phen)₂(H2O)2](NO3)4·0.5H2O (phen=1,10-phenanthroline) (1) the two Cu(II) centres exhibit a distorted square pyramidal coordination geometry linked by two nitrogen donors from adenine bridges leading to a Cu-Cu distance of 3.242(3)Å. Intramolecular and intermolecular π⋯π interactions as well as an H-bonding network were observed. The antitumor capacity of the complex has been tested in vitro against human cancer cell lines, cervical carcinoma (HeLa) and colorectal adenocarcinoma (Caco-2), by metabolic tests, using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide as reagent. The complex 1 has remarkable low IC50 values of 0.87±0.06μM (HeLa) and 0.44±0.06μM (Caco-2), when compared with values for cisplatin against the same cell lines. The interaction of complex 1 with calf thymus DNA (CT DNA) was further investigated by absorption and fluorescence spectroscopic methods. A binding constant of 5.09×10(5)M(-1) was obtained from UV-vis absorption studies.

Morphological characterization of pollens from three Apiaceae species and their ingestion by twelve-spotted lady beetle (Coleoptera: Coccinellidae)

Larvae and adults of certain species of predator lady beetles feed on pollen, guaranteeing their survival, and at times, reproduction in the absence of preferred prey. Palynology, therefore, may contribute in the investigation of botanical families visited by these predators in order to obtain this floral resource. There are records of the visitation of Apiaceae flowers by Coleomegilla maculata DeGeer, 1775 (Coleoptera, Coccinellidae), but not the ingestion of their pollen grains by this lady beetle. The external morphology of pollen grains of three Apiaceae aromatic species (Anethum graveolens L., Coriandrum sativum L., Foeniculum vulgare Mill.) was characterized, and it was evaluated the ingestion of these pollens by fourth instar larvae and adults of C. maculata upon confinement along with flowers of these Apiaceae for 24 and 48 hours. The pollen grains of those species presented similar external morphology. In the two times of exposure, the larvae ingested the same amount of pollen from the three Apiaceae species, and the amount of C. sativum pollen ingested was the same between larvae and adults. The amount of A. graveolens pollen grains ingested by the adults was significantly greater than the pollens of C. sativum and F. vulgare, in 24 hours, with the opposite occurring in 48 hours. In the first 24 hours, the adults ingested more A. graveolens pollen than the larvae, with the opposite occurring with F. vulgare. There was no significant difference in the amount of Apiaceae pollen ingested between larvae and adults in 48 hours. The results suggest that the pollen-eating habits of certain aphidophagous lady beetles may be crucial in their preservation within agro-ecosystems.

Expression of pancreatic endocrine markers by mesenchymal stem cells from human umbilical cord vein

BACKGROUND

Mesenchymal stem cells (MSCs) from human umbilical cord vein have great potential for use in cell therapy because of their ease of isolation, expansion, and differentiation, in addition to their relative acceptance from the ethical point of view. Obtaining the umbilical cord at birth does not present any risk to either mother or child.

OBJECTIVE

To isolate and promote in vitro expansion and differentiation of MSCs from human umbilical cord vein into cells with a pancreatic endocrine phenotype.

METHODS

Mesenchymal stem cells obtained from human umbilical cord vein via collagenase digestion were characterized at cytochemistry and fluorescent-activated cell sorting, and expanded in vitro. Differentiation of MSCs into an endocrine phenotype was induced using high-glucose (23 mmol/L) medium containing nicotinamide, exendin-4, and 2-mercaptoethanol. Expression of insulin, somatostatin, glucagon, and pancreatic and duodenal homeobox 1 was analyzed using immunofluorescence.

RESULTS

Cells isolated from the umbilical cord vein were MSCs as confirmed at cytochemistry and fluorescent-activated cell sorting. Expression of somatostatin, glucagon, and pancreatic and duodenal homeobox 1 by differentiated cells was demonstrated using immunofluorescence. Insulin was not expressed.

CONCLUSIONS

The MSC differentiation protocol used in the present study induced expression of some endocrine markers. Insulin was not produced by these cells, probably because of incomplete induction of differentiation.

[Peritoneal tuberculosis as a complication in a case of unclassifiable myelodysplastic/myeloproliferative disease]

We report the case of a 68-year-old male with a diagnosis of unclassifiable myelodysplatic/myeloproliferative disease (WHO classification), under prolonged steroid treatment and unsuccesful chemotherapy response, who developed progressive asthenia, thoracic pain, minimal efforts dyspnea, and abdominal distension, that initially was suspicious of splenic rupture. Exploratory laparotomy showed multiple peritoneal implants, and a diagnosis of peritoneal tuberculosis was obtained from local biopsy. Definitive diagnosis included a positive result to culture and PCR urine test, together with a possible pleural and splenic tuberculous affectation. Response to tuberculostatic treatment was successful. To the best of our knowledge, this is the first reported case with such characteristics.

Functional changes of mice Sertoli cells induced by Cr(V)

Transport of macromolecules from the interstitial testis tissue to cells at the adlumenal compartment of the seminiferous epithelium occurs naturally through Sertoli cells. In previous studies we have shown that Cr(V) intoxication disturbed spermatogenesis in mice. To test if Sertoli cells are affected by chromium, a well proved carcinogen, the uptake and the horseradish peroxidase transport ability of isolated seminiferous tubules of mice administered with a chromium(V) compound, have been studied. Male CD-R mice were exposed daily for 5 days to [CrV-BT]2- through subcutaneous injection and comparisons were made with groups of vehicle-treated mice. Using an in vitro assay we demonstrated that the seminiferous tubules were able to uptake and transport the tracer, in a much faster way than controls, mainly via intercellular and transcellular pathways, providing evidence that this functional role of Sertoli cells is affected by the Cr(V) compound. These findings might improve the knowledge on the toxicity mechanisms of chromium.

Cr(V) involvement in the toxicity pathway of testicular damage

AIM

The functional integrity of the blood-testis barrier (BTB) in male mice exposed to Cr(V) was studied in order to clarify the mechanism underlying testicular injury.

METHODS

Adult male mice were subcutaneously injected repeated doses of 8.02 micromol (0.5 ml) of Cr/mouse.day for 5 days. Animals receiving a similar volume of bis(hydroxyethyl)-aminotris(hydroxymethyl)methane buffer (BT) were used as controls. The animals were sacrificed on day 6 and small fragments of seminiferous tubules, approximately 8-10 mm length, were incised and sutured at both ends. They were exposed in vitro to horseradish peroxidase-containing culture medium for 10 minutes. Tissues were then fixed and processed for ultrastructural studies.

RESULTS

Controls and Cr(V)-treated group resulted in the uptake of the tracer by Sertoli cells. However, the major finding consisted in the permeability of the BTB only in the Cr(V)-group, as evidenced by the presence of the tracer within the junctions between the neighbouring Sertoli cells.

CONCLUSION

The BTB is disrupted in mice submitted to Cr(V). The permeability of the BTB is a crucial feature to be investigated for the understanding of lesions within the seminiferous tubule.

Chromium(VI) induced alterations in mouse spleen cells: a short-term assay

Cr(VI), the highest oxidation state for chromium, is a carcinogenic and mutagenic agent. In vivo and in vitro Cr(VI) toxic effects are related to its intracellular fate. Once inside the cell it is reduced to stable Cr(III) by cysteine, glutathione and ascorbic acid. Additionally, as Cr(V) and/or Cr(IV) intermediates have been reported in Cr(VI) reactions with biological reductants, chromium damage is thought to originate from these chemical species. This work investigated the morphology of splenic cells after short-term exposure to Cr(VI). A dose of 30 mg of K2CrO4/kg body weight was administered to mice and the effects were studied 24 and 48 h after the injections. Histological results revealed a time-dependency effect of Cr(VI) on splenic cells. Changes included enlargement of the capsule and depletion of the red pulp cells, accompanied by an increase in macrophages, 24 h after injection. Partial restoration of red pulp was noted after 48 h.

Characterization and differentiation of ruthenium(II) complexes with 1,4,7-trithiacyclononane and nitrogen heterocycles by electrospray mass spectrometry

Electrospray ionization mass spectrometry (ESIMS) was used to characterize a series of new ruthenium(II) complexes with several nitrogen heterocycles and a common ligand: the crown thioether 1,4,7-trithiacyclononane, [9]aneS(3). ESIMS allows the easy identification of the [Ru(II)Cl([9]aneS(3))Y]X complexes, where Y is a bidentate nitrogen heterocycle and X is Cl(-) or PF(6)(-), through the formation of two diagnostic ions by fragmentation of the common ligand [9]aneS(3). Structures for these ions and mechanisms for their gas-phase formation are proposed based on data from product ion spectra.

Analysis of the gene expression profile of Schistosoma mansoni cercariae using the expressed sequence tag approach

ESTs constitute rapid and informative tools with which to study gene-expression profiles of the diverse stages of the schistosome life cycle. Following a comprehensive EST study of adult worms, analysis has now targeted the cercaria, the parasite larval form responsible for infection of the vertebrate host. Two Schistosoma mansoni cercarial cDNA libraries were examined and partial sequence obtained from 957 randomly selected clones. On the basis of database searches, 551 (57.6%) ESTs generated had no homologs in the public databases whilst 308 (32.2%) were putatively identified, totaling 859 informative ESTs. The remaining 98 (10.2%) were uninformative ESTs (ribosomal RNA and non-coding mitochondrial sequences). By clustering analysis we have identified 453 different genes. The most common sequences in both libraries represented Sm8 calcium binding protein (8% of ESTs), fructose-1,6-bisphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, cytochrome oxidase subunit 1, ATP guanidine kinase and triose phosphate isomerase. One hundred and nineteen identified genes were sorted into 11 functional categories, with genes associated with energy metabolism being the most abundant (13%) and diverse. The diversity and abundance of genes associated with the transcription/translation machinery and with regulatory/signaling functions were also marked. A paramyosin transcript was identified, indicating that this gene is not exclusively expressed in adult worms and sporocysts (as had been suggested previously). The possible physiological relevance to cercariae of the presence of transcripts with homology to calcium binding proteins of the EF-hand superfamily, Gq-coupled rhodopsin photoreceptor, rod phosphodiesterase 8 subunit and peripheral-type benzodiazepine receptor is discussed.

Phoneutria nigriventer toxins block tityustoxin-induced calcium influx in synaptosomes

Neurotoxins can help the understanding of mechanisms involved in neurotransmission. We here report that two neurotoxin isoforms, Tx3-3 and Tx3-4 obtained from the venom of the spider Phoneutria nigriventer inhibited the 45Ca2+ influx in rat cortical synaptosomes induced by the scorpion venom tityustoxin. The IC50 for Tx3-3 and Tx3-4 were 0.32 and 7.9 nM, respectively. The neurotoxins Tx3-3 and Tx3-4 are very effective in inhibiting 45Ca2+ influx and they should be useful in studies involving Ca(2+)-dependent processes.

Update of the gene discovery program in Schistosoma mansoni with the expressed sequence tag approach

Continuing the Schistosoma mansoni Genome Project 363 new templates were sequenced generating 205 more ESTs corresponding to 91 genes. Seventy four of these genes (81%) had not previously been described in S. mansoni. Among the newly discovered genes there are several of significant biological interest such as synaptophysin, NIFs-like and rho-GDP dissociation inhibitor.

Evaluation of cDNA libraries from different developmental stages of Schistosoma mansoni for production of expressed sequence tags (ESTs)

A comparative study of the gene expression profile in different developmental stages of Schistosoma mansoni has been initiated based on the expressed sequence tag (EST) approach. A total of 1401 ESTs were generated from seven different cDNA libraries constructed from four distinct stages of the parasite life cycle. The libraries were first evaluated for their quality for a large-scale cDNA sequencing program. Most of them were shown to have less than 20% useless clones and more than 50% new genes. The redundancy of each library was also analyzed, showing that one adult worm cDNA library was composed of a small number of highly frequent genes. When comparing ESTs from distinct libraries, we could detect that most genes were present only in a single library, but others were expressed in more than one developmental stage and may represent housekeeping genes in the parasite. When considering only once the genes present in more than one library, a total of 466 unique genes were obtained, corresponding to 427 new S. mansoni genes. From the total of unique genes, 20.2% were identified based on homology with genes from other organisms, 8.3% matched S. mansoni characterized genes and 71.5% represent unknown genes.

The effect of 2-(4-phenylpiperidino)cyclohexanol (AH-5183), tityustoxin and ouabain on the release of acetylcholine and its mobilization from cytoplasmic and vesicular pools of rat brain cortical slices

The effect of vesicular acetylcholine (ACh) transport blocker 2-(4-phenylpiperidino)cyclohexanol (AH-5183) on the subcellular storage and release of ACh was studied in rat brain cortical slices. AH-5183 reduced the release of ACh from cortical slices stimulated by tityustoxin and ouabain. Tissue stimulated in the presence of AH-5183 contained more ACh in both the nerve terminal synaptic vesicles and cytoplasmic fraction than did tissue stimulated in drug's absence. Thus, AH-5183 blocked the tityustoxin and ouabain induced release of ACh from both cytoplasmic and vesicular pools. AH-5183 also depressed the spontaneous release of ACh from incubated slices and, in this condition, the drug had no effect in the subcellular distribution of ACh. It is suggested that AH-5183 interferes with the process of ACh release independent of its blocking action on ACh transport into the synaptic vesicles.

Effect of neonatal malnutrition on leucine renewal and protein biosynthesis in neurons of rats

Starting 1--3 days before delivery, pregnant rats were fed isocaloric diets containing either a low (5% casein) or a normal (20% casein) level of protein. At 14 days of age, the malnourished pups showed lower body, brain, and forebrain weights. The number of cells in the forebrain was lower and their size was smaller in the malnourished group. In order to study the turnover rate of 14C-leucine in the free amino acid pool and the rate of 14C-leucine incorporation into TCA-precipitable protein in neuronal cell bodies, a neuronal enriched fraction (NEF) was prepared. Malnutrition altered the free amino acid pool of the NEF by increasing the content of lysine+ornithine, glycine, and aspartic and glutamic acids and lowering that of histidine and threonine. The pools of the remaining amino acids were not altered. The turnover rate of free 14C-luecine was reduced to 60% of that of the controls. The rate of 14C-leucine incorporation into TCA-precipitable protein, corrected for its turnover rate in the free pool, was reduced to 64% of that of the controls.