Low-complexity domain-containing protein (LCDP), induced accumulation of calcium carbonate individual crystals to irregular polycrystals in the triangle sail mussel Hyriopsis cumingii.

The nacre layer is composed of sheet-like aragonite crystals, with often loosely arranged polycrystal aragonite sheets which may induce poor mechanical properties in shells. In this study, a full-length low-complexity domain-containing protein (LCDP) cDNA from the triangle sail mussel Hyriopsis cumingii was generated and its role in shell formation investigated. The full-length cDNA was 1058 bp; it had an open reading frame (ORF) of 714 bp encoding 237 amino acids and contained a 20-amino acid signal peptide at the N-terminus and two low-complexity domains. H. cumingii LCDP was not homologous with other species. Tissue expression analyses showed that LCDP was specifically expressed in the mantle. In shell repair assays, significantly higher LCDP expression was observed in the shell repair group from days 12-21 (p < 0.01). After LCDP silencing, aragonite flake shapes in pearl layers became irregular with disordered deposition, while calcium carbonate (CaCO3) crystal surfaces in prismatic layers became rougher and organic matrices between crystals appeared skeletonized, indicating the importance of biomineralization. Our in vitro CaCO3 crystallization assays showed that LCDP induced single crystals to polycrystals, probably via loose arrangement between aragonite flakes. These results provide new insights on freshwater mollusk biomineralization and a theoretical basis for improved pearl quality.

Bioaccumulation of 35 metal(loid)s in organs of a freshwater mussel (Hyriopsis cumingii) and environmental implications in Poyang Lake, China.

Benthic bioaccumulation of hazardous materials has been a great challenge to the health of lake ecosystems. As representative benthic macroinvertebrates, freshwater mussels and their accumulation characteristics have been regarded as effective indicators for assessing potential risks induced by sedimentary metal(loid)s in lakes. Here we profile organ-specific accumulation of 35 metal(loid)s in a freshwater mussel (Hyriopsis cumingii) and their correlations to metal speciation in sediments of Poyang Lake, the largest lake of China. Significant organ-specific characteristics of metal accumulation were found in gills, though higher thallium (Tl) and selenium (Se) were found in the hepatopancreas, and greater arsenic (As) mostly accumulated in gonads. Pearson correlation analysis revealed that the bioaccumulation of silver (Ag), cobalt (Co), and rare earth elements (ΣREE) in gills and As in gonads were closely associated with those in bioavailable fraction of sediments. Based on the biochemical analysis in the major organs, gills exhibited the highest enzymatic activity compared with hepatopancreas and gonads. Sedimentary metals, particularly for available Ag, Co, and ΣREE, play key roles in causing lipid peroxidation in gills and significantly promote the activities of superoxide dismutase (SOD)/glutathione reductase (GR), while many metals (e.g., cadmium, manganese, Se) inhibit the glutathione (GSH) content in gonads and hepatopancreas. Our study indicates a high physiological sensitivity of mussels to these target metals, which highlights the significance of organ-specific accumulation of metal(loid)s in understanding the potential ecological risks of sedimentary metal(loid)s in lake ecosystems.

A novel nacre matrix protein hic24 in Hyriopsis cumingii is essential for calcium carbonate nucleation and involved in pearl formation.

Matrix proteins play important roles in molluscan shell biomineralization, which helps in the understanding of mechanisms associated with pearl formation. In this study, we characterized the gene encoding a novel shell-matrix protein, hic24, in Hyriopsis cumingii and investigated its structure and function. The full cDNA sequence of hic24 is 756 bp, with an open reading frame of 654 bp encoding 217 amino acids, including a signal peptide of 18 amino acids. Sequence analysis revealed that the protein is ∼23.5 kDa, and that Gly accounted for 11.5% of the total amino acid content. Secondary structure prediction indicated a structure comprised predominantly by ß-folds. Quantitative real-time polymerase chain reaction and in situ hybridization indicated that hic24 is expressed in the dorsal epithelial cells of the mantle, indicating hic24 as a nacreous-layer matrix protein. Additionally, hic24 expression patterns during pearl biomineralization showed that hic24 regulates the growth of the later nacreous layer. After attenuating hic24 expression by RNA interference in the mantle, we observed that hic24 plays a role in biomineralization of the shell nacre by inhibiting calcium carbonate nucleation.

Removal of selenium containing algae by the bivalve Sinanodonta woodiana and the potential risk to human health.

Selenium (Se) is an essential micronutrient for animals and humans with a relatively narrow margin between nutritional essentiality and potential toxicity. Even though our previous studies have demonstrated algae could efficiently remove Se, mainly through volatilization, concern is raised about eco-risks posed by the remaining Se in algae. Here, Sinanodonta woodiana was investigated as a biofilter for the removal of Se-containing Chlorella vulgaris and for its potential risk to human health. Our results suggest filtration rates of S. woodiana were independent of Se levels in algal biomass, with a removal efficiency of between 60 and 78%. However, Se concentrations accumulated in mussels were significantly correlated with algal-borne Se levels, with a dietary assimilation efficiency ranging from 12% to 46%. Thus, a pilot biofiltration system was set up to assess uptake and depuration processes. The system was found to efficiently remove Se laden algae through the uptake by mussels, while 21% of Se in mussels could be depurated in 6 days. Among tissues, gills accumulated the highest Se concentration after assimilating algal-borne Se but shed Se compounds in the fastest pace during depuration. Health risks posed by consumption of mussels exposed to different sources of Se were further assessed. S. woodiana accumulated the highest Se concentration after exposure to waterborne SeMet, followed by dietary Se, selenite and control. The relatively higher Se levels were found in gills for all the treatments. After boiling, the most common method of cooking mussels, the greatest reduction in Se concentration occurred in mantle for the control and dietary Se groups and in muscle for the SeMet and selenite treatments. Therefore, within the safe limits, Se-containing mussels can be consumed as a dietary supplement. Overall, our research suggests incorporation of mussels into an algal treatment system can improve Se removal efficiency and also provide financial incentives for practitioners.

Identification of tumor necrosis factor receptor-associated factor 6 in the pearl mussel Hyriopsis cumingii and its involvement in innate immunity and pearl sac formation.

Tumor necrosis factor receptor-associated factor 6 (TRAF6) acts as a central intracellular signal adapter molecule that mediates the tumor necrosis factor receptor superfamily and the interleukin-1 receptor/Toll-like receptor family in vertebrates and invertebrates. In the present study, HcTRAF6, a molluscan homologue of TRAF6 from Hyriopsis cumingii, has been cloned and identified. The entire open reading frame of HcTRAF6 was found to comprise a 1965-bp region that encodes a predicted protein of 654 amino acids, which contains conserved characteristic domains including a RING domain, two TRAF-type zinc finger domains, a typical coiled coil and the MATH domain. Phylogenetic analysis revealed that HcTRAF6 was aggregated closely with CsTRAF6 from Cyclina sinensis in the invertebrate cluster of mollusks. Further, qRT-PCR analysis showed that HcTRAF6 mRNA was extensively distributed in mussel tissues with a high expression in gills. After immune stimulation with Aeromonas hydrophila and lipopolysaccharides, the transcription of HcTRAF6 was obviously induced in the gills and hemocytes. In addition, significant fluctuation in HcTRAF6 expression was observed in the pearl sac, gills and hemocytes after mantle implantation. These findings confirmed its role in the alloimmune response. Dual-luciferase reporter assay showed that over-expression of HcTRAF6 could enhance the activity of the NF-κB reporter in a dose-dependent manner. Further, the RNA interference showed that the up-regulation of antimicrobial peptides in anti-bacterial infection was strongly suppressed in HcTRAF6-silenced mussels and that depletion of HcTRAF inhibited the elimination of A. hydrophila. All these findings together prove that HcTRAF6 functions as an efficient regulator in innate immune mechanisms against invading pathogens and the alloimmune mechanism after mantle implantation in H. cumingii.

Anti-inflammatory activity of cyclo-oxygenase2 inhibitory anionic protein fraction from Lamellidens marginalis (Lamarck).

Aqueous extract of freshwater mussel, Lamellidens marginalis is known to possess potent antioxidant and anti-inflammatory activity. Here, we have made an attempt to purify anti-inflammatory protein from Lamellidens marginalis extract (LME). Aqueous LME was prepared, and total protein was precipitated by 60% ammonium sulfate followed by purification through ion exchange chromatography. Isolated fractions were studied for anti-inflammatory activity in in vitro and in vivo experimental models. Active fractions were characterized by SDS PAGE and HPLC. Protein recovered from ammonium sulfate precipitation showed four distinct peaks in diethyl-aminoethyl cellulose ion exchange chromatography when eluted with stepwise salt gradient. Protein fraction eluted in 0.5 M sodium chloride solution showed maximum specific activity and anti-inflammatory activity in acute model and adjuvant induced chronic inflammation model. This fraction also showed cyclo-oxygenase 2 (COX2) enzyme inhibitory activity in in-vitro system. In SDS-PAGE 0.5 M NaCl fraction showed multiple bands after Coomassie brilliant blue staining and three distinct peaks in HPLC. In this study, we identified an anti-inflammatory protein fraction with high anionic property which could be attributed to inhibition of COX2 enzyme activity.

Characterization of allograft inflammatory factor-1 in Hyriopsis cumingii and its expression in response to immune challenge and pearl sac formation.

The allograft inflammatory factor-1 (AIF-1) is one of the key factors associated with inflammatory response and immune defense. In the present study, we report the identification and characterization of AIF-1 from triangle sail mussel Hyriopsis cumingii (HcAIF-1). The full-length cDNA of HcAIF-1 consisted of a 5'-terminal untranslated region (UTR) of 80 bp, a 3'-UTR of 420 bp with a poly (A) tail, and an open reading frame of 444 bp encoding a polypeptide of 147 amino acids with two conserved EF-hand Ca2+-binding motifs. HcAIF-1 mRNA and protein were expressed in all examined tissues and showed higher mRNA expression levels were observed in immune tissues, especially hemocytes and mantle, and the highest protein expression level was in mantle. The expression level of HcAIF-1 mRNA was significantly upregulated in hemocytes 12-48 h after lipopolysaccharide challenge. After mantle tissue implantation, the expression level of this gene in pearl sac decreased significantly at 3-48 h (P < 0.01), and then was significantly upregulated at 96 h (P < 0.05) and recovered to the control level at 21-28 d. There was significant increase HcAIF-1 transcript abundance in hemocytes 96 h (P < 0.05) after mantle tissue implantation. The phagocytosis rate was significantly enhanced in hemocytes 3-24 h (P < 0.01) after the injection of recombinant HcAIF-1 protein. These findings suggest that HcAIF-1 is important in the underlying mechanism of the innate immune responses and pearl sac formation of H. cumingii.

A Novel Matrix Protein Hic31 from the Prismatic Layer of Hyriopsis Cumingii Displays a Collagen-Like Structure.

In this study, we clone and characterize a novel matrix protein, hic31, from the mantle of Hyriopsis cumingii. The amino acid composition of hic31 consists of a high proportion of Glycine residues (26.67%). Tissue expression detection by RT-PCR indicates that hic31 is expressed specifically at the mantle edge. In situ hybridization results reveals strong signals from the dorsal epithelial cells of the outer fold at the mantle edge, and weak signals from inner epithelial cells of the same fold, indicating that hic31 is a prismatic-layer matrix protein. Although BLASTP results identify no shared homology with other shell-matrix proteins or any other known proteins, the hic31 tertiary structure is similar to that of collagen I, alpha 1 and alpha 2. It has been well proved that collagen forms the basic organic frameworks in way of collagen fibrils and minerals present within or outside of these fibrils. Therefore, hic31 might be a framework-matrix protein involved in the prismatic-layer biomineralization. Besides, the gene expression of hic31 increase in the early stages of pearl sac development, indicating that hic31 may play important roles in biomineralization of the pearl prismatic layer.

Identification and expression analysis of the MSP130-related-2 gene from Hyriopsis cumingii.

MSP130-related-2 is thought to play a role in bio-mineralization as revealed in Crassostrea gigas and sea urchins. In this study, an MSP130-related-2 gene was isolated from Hyriopsis cumingii (HcMSP130-related-2) and characterized for the first time. The HcMSP130-related-2 cDNA was 2307 bp in length and consisted of a 572-bp 5'-untranslated region (5'-UTR), a 1239-bp open reading frame encoding 430-amino acid residues, and a 439-bp 3'-UTR. The molecular weight of the peptide was predicted to be 48551.3 Da, with a theoretical isoelectric point of 4.78 and instability index of 32.74, indicating that the protein is stable. The HcMSP130-related-2 amino acid residues included a signal peptide and several potential N-glycosylation sites. NCBI BLAST analysis indicated that this full-length amino acid sequence showed the highest similarity with HcMSP130-related-2 from C. gigas (45%) and about 38% identity with that from SpMSP130-rel-2 and Strongylocentrotus purpuratus. A phylogenetic tree showed that HcMSP130-rel-2 clustered with MSP130 from C. gigas. HcMSP130-related-2 was expressed in various tissues, including the mantle, blood, gill, foot, liver, kidney, intestine, and muscle, with the highest transcripts found in the mantle. Quantitative real-time polymerase chain reaction was used to analyze the expression of the HcMSP130- related-2 gene in grass carp after inducing shell damage. HcMSP130- related-2 expression was upregulated significantly in the mantle within 7 days (P < 0.05) after damage; however, the expression remained unchanged in the adductor muscle tissues (P > 0.05). These data suggest that HcMSP130-related-2 might be involved in shell formation in H. cumingii.

Identification of housekeeping genes suitable for gene expression analysis in the pearl mussel, Hyriopsis cumingii, during biomineralization.

Quantitative real-time polymerase chain reaction is a sensitive technique for quantifying gene expression levels. One or more appropriate reference genes must be selected to accurately compare mRNA transcript levels across different samples and tissues. The freshwater pearl, Hyriopsis cumingii (Lea), is an important economic species cultured in China. To date, no reference genes for gene expression analysis in this species have been validated. This study aimed to compare the relative expression of seven housekeeping genes across different tissue types and in the mantle or pearl sac during three biomineralization processes: seasonal shell growth, shell healing and pearl-sac formation in H. cumingii. Three programs evaluated the expression stabilities of the seven genes: BestKeeper, geNorm and NormFinder. The beta actin gene (ACTB), commonly used as a housekeeping gene in many studies, was the least stable. The expressions of Ubiquitin (Ubi) and Ribosomal protein L18 (Rpl18) and Elongation factor 1-alpha (EF1α) were more stable than the remaining four genes. Therefore, we suggest that Ubi, Rpl18 and EF1α are suitable reference genes. The three selected reference genes are expected to facilitate analysis of gene expressions during shell or pearl formation in H. cumingii.

Cloning, differential tissue expression of a novel hcApo gene, and its correlation with total carotenoid content in purple and white inner-shell color pearl mussel Hyriopsis cumingii.

As a molecular carrier and storage protein, apolipoprotein (Apo) mediates the intracellular uptake of lipids, proteins, vitamins and carotenoids. In this study, we identified a novel Apo gene, designated hcApo, from the freshwater pearl mussel Hyriopsis cumingii. The complete hcApo cDNA consists of 4104 nucleotides with an open reading frame encoding 1155 amino acid residues. The hcApo protein contains a conserved lipoprotein N-terminal domain (LPD-N) that is a characteristic of the large lipid transfer protein (LLTP) superfamily. The hcApo mRNA is constitutively expressed in a wide range of tissues with the highest expression level in the liver. Moreover, differential expression analysis revealed that the hcApo gene is more highly expressed in the liver, kidney, mantle and gill of purple line mussels compared to white line mussels. In situ hybridization investigations of the precise expression site of hcApo mRNA in the mantle showed that hcApo mRNA is specifically expressed in the outer epithelial cells of the middle fold and the inner epithelial cells of the outer fold of the mantle, as well as throughout the outer epithelium of the outer fold and ventral mantle. Another very important finding is that significantly positive correlation existed between the hcApo gene expression level and the total carotenoid content in purple line mussels. These findings may provide a better understanding of the roles of hcApo in the molecular mechanisms of shell formation and coloring of H. cumingii.

Characterization of cDNAs for calmodulin and calmodulin-like protein in the freshwater mussel Hyriopsis cumingii: differential expression in response to environmental Ca(2+) and calcium binding of recombinant proteins.

Calmodulin and calmodulin-like protein are two crucial calcium regulators in bivalves. However, molecular characteristics and expression patterns of these genes in the freshwater mussel are poorly understood. In this study, two cDNAs encoding novel calmodulin and calmodulin-like protein (HcCaM and HcCaLP) were cloned and characterized from the freshwater pearl mussel Hyriopsis cumingii. The full-length cDNA of HcCaM was 726 bp, including a 118-bp 5'-untranslated region (UTR), a 447-bp open reading frame (ORF), and a 161-bp 3'-UTR. The 1217-bp HcCaLP cDNA comprised of a 51-bp 5'-UTR, a 447-bp ORF, and a 716-bp 3'-UTR. The potential phosphorylation sites of, Arg(80) and Phe(100) in deduced HcCaM were mutated to Thr(80) and Tyr(100) in HcCaLP. Tissue-specific expression analysis revealed that HcCaM mRNA was prominently expressed in the gill, mantle center, and foot. In contrast, HcCaLP mRNA was mainly expressed in the mantle edge. The recombinant HcCaM and HcCaLP proteins expressed in Escherichia coli showed the typical Ca(2+) dependent electrophoretic shift characterization as CaM and differed in the calcium binding affinity. The calcium stimulation test that lasted 5 weeks implied that HcCaM and HcCaLP had differential expression patterns in response to various environmental Ca(2+) concentrations (0.25-1.25 mM). The expression of HcCaM mRNA was up-regulated by low Ca(2+) concentration (0.25 mM), and the highest expression of HcCaLP mRNA occurred under Ca(2+) concentration of 1 mM.

Molecular properties and immune defense of two ferritin subunits from freshwater pearl mussel, Hyriopsis schlegelii.

Ferritin is a conserved iron-binding protein involved in cellular iron metabolism and host defense. In the present study, two distinct cDNAs for ferritins in the freshwater pearl mussel Hyriopsis schlegelii were identified (designated as HsFer-1 and HsFer-2) by SMART RACE approach and expressed sequence tag (EST) analysis. The full-length cDNAs of HsFer-1 and HsFer-2 were of 760 and 877 bp, respectively. Both of the two cDNAs contained an open reading frame (ORF) of 522 bp encoding for 174 amino acid residues. Sequence characterization and homology alignment indicated that HsFer-1 and HsFer-2 had higher similarity to H-type subunit of vertebrate ferritins than L-type subunit. Analysis of the HsFer-1 and HsFer-2 untranslated regions (UTR) showed that both of them had an iron response element (IRE) in the 5'-UTR, which was considered to be the binding site for iron regulatory protein (IRP). Quantitative real-time PCR (qPCR) assays were employed to examine the mRNA expression profiles. Under normal physiological conditions, the expression level of both HsFer-1 and HsFer-2 mRNA were the highest in hepatopancreas, moderate in gonad, axe foot, intestine, kidney, heart, gill, adductor muscle and mantle, the lowest in hemocytes. After stimulation with bacteria Aeromonas hydrophila, HsFer-1 mRNA experienced a different degree of increase in the tissues of hepatopancreas, gonad and hemocytes, the peak level was 2.47-fold, 9.59-fold and 1.37-fold, respectively. Comparatively, HsFer-2 showed up-regulation in gonad but down-regulation in hepatopancreas and hemocytes. Varying expression patterns indicate that two types of ferritins in H. schlegelii might play different roles in response to bacterial challenge. Further bacteriostatic analysis showed that both the purified recombinant ferritins inhibited the growth of A. hydrophila to a certain degree. Collectively, our results suggest that HsFer-1 and HsFer-2 are likely to be functional proteins involved in immune defense against bacterial infection.

Pearl extract enhances the migratory ability of fibroblasts in a wound healing model.

CONTEXT: For 2000 years, traditional Chinese medicine has been used as a remedy for general health improvement, including the fight against aging. Pearl powder has recently been used as a health food that has antioxidant, antiaging, antiradioactive, and tonic activities for cells; it is also applied to cure aphthous ulcer, gastric ulcer, and duodenal ulcer on clinical therapy. In addition, the mother of pearl, nacre, could enhance the cell adhesion and tissue regeneration of skin fibroblasts. OBJECTIVE: Fibroblast is regarded as indispensable in the processes of wound healing. Therefore, the effect of pearl extract (PL) on fibroblasts is investigated in this study. MATERIALS AND METHODS: PL is produced by a room temperature super extraction system (Taiwan patent no. I271 220). DMEM medium containing PL (300 µg/mL) was used to examine the effect of migration-promoting potential on human fibroblast cell line or human primary fibroblast cells in a wound healing model in vitro. RESULTS: Medium containing PL (300 µg/mL) demonstrated that the migratory cell numbers of fibroblasts were three times more than that without PL, and mRNA expression of collagen type III was higher than in collagen type I in fibroblasts. It revealed a migration-promoting potential of human fibroblasts in a wound healing model in vitro. DISCUSSION AND CONCLUSION: The present study found that the migration-promoting effect in PL, which could be a supplement in cell culture. These data suggest PL could be useful for enhancing the wound healing of fibroblasts.

Arsenic toxicity: a heart-breaking saga of a freshwater mollusc.

The freshwater wetland systems of India is a complex habitat that supports a broad range of diverse species including molluscs, which play an important role in supplementing third world countries. In the arsenic affected flood plains of West Bengal, a huge amount of arsenic laden groundwater is raised for the purpose of irrigation. Agricultural runoffs and flood water movement during monsoon may cause accumulation of arsenic in the adjacent freshwater aquifers, the common habitat of Lamellidens marginalis (Mollusca; Bivalvia; Eulamellibranchiata), a filter feeder, sensitive to altered environmental conditions. To examine the nature of toxicity induced by inorganic arsenic on both the haemocytes and tissues of the invertebrate heart, the animals were exposed to five different sublethal concentrations of sodium arsenite for a maximum time span of 30 days in vitro. Significant differences were recorded in the total haemocyte count, biochemical and histopathological parameters of the heart of L. marginalis under the arsenic induced stress. Our observations indicate the development of profound haematopoietic and cardiac stress under the sublethal inorganic arsenite exposure and it also implies the nature of risk imposed on the freshwater aquatic ecosystem under potential arsenic contamination.

Chemical analysis of a polysaccharide from Cristaria plicata (Leach).

A polysaccharide (MPS) isolated from Cristaria plicata (Leach) consisted of d-glucose. Its structural characteristics were investigated by High Performance Liquid Chromatography (HPLC), infrared analysis, gas chromatography-MS, total acid hydrolysis, methylation analysis, periodate oxidation and Smith degradation. The results indicated that the polysaccharide of C. plicata (Leach) has the weight-average molecular weight of about 2.97 × 106 Da. The structure of the polysaccharide was composed of glucose with α-(1 → 4)-linkages with short exterior chains. The fundamental information obtained from this work is beneficial to the interpretation in the relationship of the polysaccharide structure and its biological functions, and suggests that the polysaccharide from mussel may contribute to be used as a dietary supplement for health foods and therapeutics.

Prevention of the progression of adjuvant induced arthritis by oral supplementation of Indian fresh water mussel (Lamellidens marginalis) aqueous extract in experimental rats.

AIM OF THIS STUDY: Mussel is well accepted as food all over India. Beside for its nutritive value, people residing in Kosi river basin, Bihar, India, consume a preparation of soup, made from the footpad of molluscan species, with the belief that it gives relief from signs and symptoms of joint pain and related problems. This study was designed to explore the preventive activity of Indian fresh water mussel (Lamellidens marginalis) aqueous extract oral supplementation in experimental arthritis model. MATERIALS AND METHODS: Arthritis was induced in male albino rats by intradermal injection of Freund's complete adjuvant in right hind footpad. Lamellidens marginalis extract (LME1, 500 mg/kg/day and LME2, 1 g/kg/day) peroral supplementation started from the 1st day after adjuvant injection and was continued for the subsequent 13 days. Severity of arthritis was evaluated from paw diameter, ankle diameter, paw weight, urinary hydroxyproline, glucosamine level, serum interleukin-1ß, IL6, IL10, CINC1, TNFα level, lysosomal enzyme levels and from histopathological assessment. RESULTS: Lamellidens marginalis extract supplementation significantly (p<0.05) decreased paw diameter, ankle diameter, and paw weight in treated groups (LME1, 500 mg/kg/day and LME2, 1 g/kg/day) as compared with arthritic group. Urinary hydroxyproline, glucosamine level, serum IL1ß, IL6, CINC1, TNFα, IL10 and lysosomal enzyme levels were restored significantly (p<0.05) in treated groups (LME1, 500 mg/kg/day and LME2, 1 g/kg/day) as compared to arthritic group. Synovial membrane damage and neutrophil infiltration in histopathological examination was restored significantly by LME supplementation as compared to arthritic group. CONCLUSIONS: Thus, it might be concluded that experimental animals supplemented with Lamellidens marginalis extract were protected against the severity of disease progression in adjuvant induced arthritis.

Effects of pearl powder extract and its fractions on fibroblast function relevant to wound repair.

The water soluble matrix (WSM) of pearl powder [Hyriopsis cumingii Lea (Unionidae)] was extracted, and the insoluble residue was demineralized, size-fractionated, and named as MR14 (> 14 kDa), MR3-14 (3-14 kDa), and MR3 (< 3 kDa). The effects of WSM, MR14, MR3-14, and MR3 on primary mouse oral fibroblast proliferation, collagen accumulation, matrix metalloproteinase-2, -9 (MMP-2, -9) activities, and tissue inhibitor of metalloproteinase-1 (TIMP-1) production were tested by MTT assay, chloramine T method, gelatin zymography, and enzyme-linked immunosorbent assay (ELISA), respectively. The results showed that the WSM and MR14 could significantly (p < 0.05) promote fibroblast proliferation; all of the fractions could significantly promote collagen accumulation; MR14 significantly (p < 0.05) inhibited MMP-2 activity; and all of the fractions could significantly promote TIMP-1 production. This study has proved that the mechanism by which pearl powder promotes wound healing is partly due to its ability to stimulate fibroblast mitosis, collagen deposition, and TIMP-1 production, and the major active fraction may be MR14.

Contaminant concentrations in Asian carps, invasive species in the Mississippi and Illinois Rivers.

Populations of invasive fishes quickly reach extremely high biomass. Before control methods can be applied, however, an understanding of the contaminant loads of these invaders carry is needed. We investigated differences in concentrations of selected elements in two invasive carp species as a function of sampling site, fish species, length and trophic differences using stable isotopes (delta (15)N, delta (13)C). Fish were collected from three different sites, the Illinois River near Havana, Illinois, and two sites in the Mississippi River, upstream and downstream of the Illinois River confluence. Five bighead carp (Hypophthalmichthys nobilis) and five silver carp (Hypophthalmichthys molitrix) from each site were collected for muscle tissue analyses. Freshwater mussels (Amblema plicata) previously collected in the same areas were used as an isotopic baseline to standardize fish results among sites. Total fish length, trophic position, and corrected (13)C, were significantly related to concentrations of metals in muscle. Fish length explained the most variation in metal concentrations, with most of that variation related to mercury levels. This result was not unexpected because larger fish are older, giving them a higher probability of exposure and accumulation of contaminants. There was a significant difference in stable isotope profiles between the two species. Bighead carp occupied a higher trophic position and had higher levels of corrected (13)C than silver carp. Additionally bighead carp had significantly lower concentrations of arsenic and selenium than silver carp. Stable isotope ratios of nitrogen in Asian carp were at levels that are more commonly associated with higher-level predators, or from organisms in areas containing high loads of wastewater effluent.