Salivary Gland Mucosa-Associated Lymphoid Tissue-Type Lymphoma From Sjogren's Syndrome Patients in the Majority Express Rheumatoid Factors Affinity-Selected for IgG

Objective: Patients with Sjӧgren's syndrome (SS) have an increased risk of developing malignant B cell lymphomas, particularly mucosa-associated lymphoid tissue (MALT)–type lymphomas. We have previously shown that a predominant proportion of patients with SS-associated salivary gland MALT lymphoma express somatically hypermutated IgM with strong amino acid sequence homology with stereotypic rheumatoid factors (RFs). The present study was undertaken in a larger cohort of patients with SS-associated MALT lymphoma to more firmly assess the frequency of RF reactivity and the significance of somatic IGV-region mutations for RF reactivity. Methods: B cell antigen receptors (BCRs) of 16 patients with SS-associated salivary gland MALT lymphoma were analyzed. Soluble recombinant IgM was produced of 12 MALT lymphoma samples, including 1 MALT lymphoma sample that expressed an IgM antibody fitting in a novel IGHV3-30–encoded stereotypic IGHV subset. For 4 of the 12 IgM antibodies from MALT lymphoma samples, the somatically mutated IGHV and IGKV gene sequences were reverted to germline configurations. Their RF activity and binding affinity were determined by enzyme-linked immunosorbent assay and surface plasmon resonance, respectively. Results: Nine (75%) of the 12 IgM antibodies identified in patients with SS-associated salivary gland MALT lymphoma displayed strong monoreactive RF activity. Reversion of the IGHV and IGKV mutations to germline configuration resulted in RF affinities for IgG that were significantly lower for 3 of the 4 somatically mutated IgM antibodies. In stereotypic IGHV3-7/IGKV3-15–encoded RFs, a recurrent replacement mutation in the IGKV3-15–third complementarity-determining region was found to play a pivotal role in the affinity for IgG-Fc. Conclusion: A majority of patients with SS-associated salivary gland MALT lymphoma express somatically mutated BCRs that are selected for monoreactive, high-affinity binding of IgG-Fc. These data underscore the notion that soluble IgG, most likely in immune complexes in inflamed tissues, is the principal autoantigen in the pathogenesis of a variety of B cell lymphomas, particularly SS-associated MALT lymphomas

Sulindac targets nuclear β-catenin accumulation and Wnt signalling in adenomas of patients with familial adenomatous polyposis and in human colorectal cancer cell lines

Nonsteroidal anti-inflammatory drugs (NSAIDs) have chemopreventive potential against colorectal carcinomas (CRCs). Inhibition of cyclooxygenase (COX)-2 underlies part of this effect, although COX-2-independent mechanisms may also exist. Nonsteroidal anti-inflammatory drugs appear to inhibit the initial stages of the adenoma-carcinoma sequence, suggesting a link to the APC/beta-catenin/TCF pathway (Wnt-signalling pathway). Therefore, the effect of the NSAID sulindac on nuclear (nonphosphorylated) beta-catenin and beta-catenin/TCF-mediated transcription was investigated. Nuclear #946;-catenin expression was assessed in pretreatment colorectal adenomas and in adenomas after treatment with sulindac from five patients with familial adenomatous polyposis (FAP). Also, the effect of sulindac sulphide on beta-catenin/TCF-mediated transcription was studied. Adenomas of FAP patients collected after treatment with sulindac for up to 6 months showed less nuclear beta-catenin expression compared to pretreatment adenomas of the same patients. Sulindac sulphide abrogated beta-catenin/TCF-mediated transcription in the CRC cell lines DLD1 and SW480, and decreased the levels of nonphosphorylated beta-catenin. As a result, the protein levels of the positively regulated TCF targets Met and cyclin D1 were downregulated after sulindac treatment. This study provides in vivo and in vitro evidence that nuclear beta-catenin localisation and beta-catenin/TCF-regulated transcription of target genes can be inhibited by sulindac. The inhibition of Wnt-signalling provides an explanation for the COX-2-independent mechanism of chemoprevention by NSAID

Characterization and Expression of Glutamate Dehydrogenase in Response to Acute Salinity Stress in the Chinese Mitten Crab, Eriocheir sinensis

Glutamate dehydrogenase (GDH) is a key enzyme for the synthesis and catabolism of glutamic acid, proline and alanine, which are important osmolytes in aquatic animals. However, the response of GDH gene expression to salinity alterations has not yet been determined in macro-crustacean species.GDH cDNA was isolated from Eriocheir sinensis. Then, GDH gene expression was analyzed in different tissues from normal crabs and the muscle of crabs following transfer from freshwater (control) directly to water with salinities of 16‰ and 30‰, respectively. Full-length GDH cDNA is 2,349 bp, consisting of a 76 bp 5'- untranslated region, a 1,695 bp open reading frame encoding 564 amino acids and a 578 bp 3'- untranslated region. E. sinensis GDH showed 64-90% identity with protein sequences of mammalian and crustacean species. Muscle was the dominant expression source among all tissues tested. Compared with the control, GDH expression significantly increased at 6 h in crabs transferred to 16‰ and 30‰ salinity, and GDH expression peaked at 48 h and 12 h, respectively, with levels approximately 7.9 and 8.5 fold higher than the control. The free amino acid (FAA) changes in muscle, under acute salinity stress (16‰ and 30‰ salinities), correlated with GDH expression levels. Total FAA content in the muscle, which was based on specific changes in arginine, proline, glycine, alanine, taurine, serine and glutamic acid, tended to increase in crabs following transfer to salt water. Among these, arginine, proline and alanine increased significantly during salinity acclimation and accounted for the highest proportion of total FAA.E. sinensis GDH is a conserved protein that serves important functions in controlling osmoregulation. We observed that higher GDH expression after ambient salinity increase led to higher FAA metabolism, especially the synthesis of glutamic acid, which increased the synthesis of proline and alanine to meet the demand of osmoregulation at hyperosmotic conditions

A cross-sectional study of self-reported chemical-related sensitivity is associated with gene variants of drug-metabolizing enzymes

BACKGROUND: N-acetyltransferases (NAT) and glutathione S-transferases (GST) are involved in the metabolism of several ubiquitous chemical substances leading to the activation and detoxification of carcinogenic heterocyclic and aromatic amines. Since polymorphisms within these genes are described to influence the metabolism of ubiquitous chemicals, we conducted the present study to determine if individuals with self-reported chemical-related sensitivity differed from controls without self-reported chemical-related sensitivity with regard to the distribution of genotype frequencies of NAT2, GSTM1, GSTT1, and GSTP1 polymorphisms. METHODS: Out of 800 subjects who answered a questionnaire of ten items with regard to their severity of chemical sensitivity 521 unrelated individuals agreed to participate in the study. Subsequently, genetic variants of the NAT2, GSTM1, GSTT1, and GSTP1 genes were analyzed. RESULTS: The results show significant differences between individuals with and without self-reported chemical-related sensitivity with regard to the distribution of NAT2, GSTM1, and GSTT1 gene variants. Cases with self-reported chemical-related sensitivity were significantly more frequently NAT2 slow acetylators (controlled OR = 1.81, 95% CI = 1.27–2.59, P = 0.001). GSTM1 and GSTT1 genes were significantly more often homozygously deleted in those individuals reporting sensitivity to chemicals compared to controls (GSTM1: controlled OR 2.08, 95% CI = 1.46–2.96, P = 0.0001; GSTT1: controlled OR = 2.80, 95% CI = 1.65–4.75, P = 0.0001). Effects for GSTP1 gene variants were observed in conjunction with GSTM1, GSTT1 and NAT2 gene. CONCLUSION: The results from our study population show that individuals being slow acetylators and/or harbouring a homozygous GSTM1 and/or GSTT1 deletion reported chemical-related hypersensitivity more frequently

Free energies of binding of R- and S-propranolol to wild-type and F483A mutant cytochrome P450 2D6 from molecular dynamics simulations

Detailed molecular dynamics (MD) simulations have been performed to reproduce and rationalize the experimental finding that the F483A mutant of CYP2D6 has lower affinity for R-propranolol than for S-propranolol. Wild-type (WT) CYP2D6 does not show this stereospecificity. Four different approaches to calculate the free energy differences have been investigated and were compared to the experimental binding data. From the differences between calculations based on forward and backward processes and the closure of thermodynamic cycles, it was clear that not all simulations converged sufficiently. The approach that calculates the free energies of exchanging R-propranolol with S-propranolol in the F483A mutant relative to the exchange free energy in WT CYP2D6 accurately reproduced the experimental binding data. Careful inspection of the end-points of the MD simulations involved in this approach, allowed for a molecular interpretation of the observed differences

Effect of various levels of squid protein on growth and some biochemical parameters of Penaeus japonicus juveniles

Abstract only.An unknown growth factor previously suspected in squid meal was found in the protein fraction of squid (Loligo vulgaris). It is clearly different from hydro-alcohol-soluble feed attractants that are also present in squid meal. This squid protein fraction (SPF) improves the growth of Penaeus japonicus juveniles when added either in a semi-purified or in a more complex mixed diet. This growth-promoting effect does not seem to be related to the amino acid composition of SPF. In order to obtain more information on its action, several levels (1.5 to 16.0%) of SPF were added to a mixed diet. The diets were isoproteic (59% D.M.), isolipidic (8.5% D.M.), supplemented with vitamins, cholesterol, glucosamine, etc. They were fed as wet pellets to 3 replicates of 15 shrimp; blue mussel was used as the control. The growth of shrimp increased with the SPF level and attained a plateau above 6%. Body weight was significantly higher than that of the control group at this level. RNA content and RNA:DNA ratio increased with the SPF level indicating that growth was improved more by hypertrophy than by hyperplasy of the cells. The hepatosomatic ratio remained unchanged. The assay of two digestive enzymes, proteases and amylases, showed no clear effect of SPF on protease or amylase activities. More experiments are needed to explain the effect of the unknown growth factor of SPF

Effect of squid extracts on time course. Appearance of glucose and free aminoacids in haemolymph in Penaeus japonicus after feeding : preliminary results

International audienc

Recent and old duplications in crustaceans "Internal Transcribed Spacer 1" : structural and phylogenetic implications

Internal Transcribed Spacer structures are important in preserving accessibility to specific enzymes for the maturation of rRNAs. ITS1 sequences reported in the literature in Crustaceans range between 182 and 820 bp and are characterized by the absence of repeats or the presence of only a limited number of microsatellites. Here, we sequenced ITS1 for a range of shrimp families (infraorder Caridea) and show that most taxa have much larger ITS1 sequences. We find a high number of microsatellites in Alpheus hebes and Crangon crangon and we report repeat units in Pandalidae, Palaemonidae and mainly in Alpheidae species. Up to four repeats were found in A. vanderbilti (1915 bp), A. rostratus (1635 bp) and A. lottini (1625 bp). In general, four helices were found in ITS1. Repeat units led to extra hairpins and loops. No conserved positions occurred except in helix 4. Three clades were defined in A. lottini for the first time. We estimated the ITS1 divergence rate for the three clades of A. lottini collected in French Polynesia using existing calibrations of substitution rates. Rates of sequence evolution are largely influenced by repeat units, which likely evolve separately. By comparison with COI marker, we estimated the divergence rate of the whole ITS1 sequence to range from 0.5 to 1.4% Pmy and between 0.12 and 0.5% for the 3' end of ITS1 located outside the repeat units. Given the degree of identity between repeats, we suggest that a duplication event recently occurred in A. floridanus (98% identity) whereas an ancient duplication happened in A. sulcatus (50% identity) early at the origination of the group Alpheidae, approximately 50 mya ago. In conclusion, our results highlight an over representation of shorter ITS1 sequences in public repositories, and underlines the importance to further understand patterns of molecular evolution of this functionally important gene