Cloning and characterization of cDNA for carp matrix metalloproteinase 9

ABSTRACT: We have cloned a cDNA encoding the MMP-9 from a carp epidermal cell (EPC) cDNA library. The clone contains a 2025-base pair (bp) open reading frame encoding a protein of 674 amino acids. The deduced amino acid sequence shares 68% and 69% identity with medaka and Japanese flounder MMP-9. The hinge domain of the carp MMP-9, like those of the other non-mammalian species, lacks a type V collagen-like region that is typical of mammalian MMP-9. Gelatin zymography and immunoblot analysis of conditioned media of EPC cells and cDNA-transfected COS-7 cells detected a 76-kDa gelatinase. The apparent molecular mass of the carp zymogen is much smaller than those of its mammalian counterparts while almost identical with that of chicken 75-kDa gelatinase B-like enzyme. Although hypo-osmotic stress induced the elevation of MMP-9 mRNA level in EPC cells, no significant change in the protein in conditioned medium was detected during hypo-osmotic stress. Northern blot analysis detected a large amount of MMP-9 mRNA in carp kidney and spleen, suggesting the high expression of MMP-9 in blood cells, neutrophils, and macrophages. The smaller amount of MMP-9 mRNA was detected in gill, heart, fin, and eye, whereas none of the mRNA was detected in the hepatopancreas, intestine, brain, muscle, and skin.     

cDNA cloning and characterization of two gelatinases from Japanese flounder

SUMMARY: Toughness is one of the most important elements that define the commercial value of the raw meat of fish. Degradation of the extracellular matrix is thought to be a cause of postmortem tenderization of fish meat. A previous study has suggested that this tenderization is caused mainly by metalloproteinases. The present study seeks to identify the proteinase(s) involved in tenderization; hence, cloned cDNA of two gelatinases from Japanese flounder, which showed high homology with mammalian matrix metalloproteinase (MMP)-2 and MMP-9, were designated as jfMMP-2 and jfMMP-9 , respectively. Northern blot analysis revealed that jfMMP-2 mRNA was expressed almost ubiquitously in adult tissues including the brain, muscle, gill, heart, gut, kidney, spleen, testis, and ovary. In contrast, the expression of jfMMP-9 mRNA was observed in those tissues which were abundant in blood cells, such as kidney, spleen, heart, and gill. Both recombinant proteins (jfMMP-2 and jfMMP-9) produced with the COS-7 cell system exhibited gelatin-degrading activity that was sensitive to 1,10-phenanthroline, a typical metalloproteinase inhibitor.     

Biocontrol of Pythium root rot on lisianthus using a new dark septate endophytic fungus Hyaloscypha variabilis J1PC1

European Journal of Plant Pathology - Pythium root rot is one of the most destructive diseases on lisianthus in Japan. Current management strategies against Pythium root rot are insufficient in...     

Schema-dependent gene activation and memory encoding in neocortex

When new learning occurs against the background of established prior knowledge, relevant new information can be assimilated into a schema and thereby expand the knowledge base. An animal model of this important component of memory consolidation reveals that systems memory consolidation can be very fast. In experiments with rats, we found that the hippocampal-dependent learning of new paired associates is associated with a striking up-regulation of immediate early genes in the prelimbic region of the medial prefrontal cortex, and that pharmacological interventions targeted at that area can prevent both new learning and the recall of remotely and even recently consolidated information. These findings challenge the concept of distinct fast (hippocampal) and slow (cortical) learning systems, and shed new light on the neural mechanisms of memory assimilation into schemas.     

Effects of Dietary Brown Rice on the Growth Performance,Systemic Oxidative Status,and Splenic Inflammatory Responses of Broiler Chickens under Chronic Heat Stress

The aim of this study was to evaluate the effects of dietary brown rice on the growth performance, systemic oxidative status, and splenic inflammatory responses of broiler chickens under both thermo-neutral and chronic heat stress conditions. Forty 12-day-old male broiler chickens (ROSS 308) were randomly assigned to two groups and fed either a control diet (corn-based) or a brown rice-based diet. After seven days (19 days old), both groups were randomly divided into two sub-groups (n=10), one of which was exposed to heat stress (33°C for 14 days), while the other was maintained at 24°C. Heat exposure reduced the body weight gain and feed intake (p<0.01) of both groups. In terms of oxidative plasma states, heat exposure reduced the glutathione peroxidase activity and increased the ceruloplasmin content, while the 2-thiobarbituric acid reactive substance and reduced glutathione levels were not affected adversely. Heat exposure activated the immune responses, as evidenced by increased plasma immunoglobin levels, and altered splenic immune-related gene expressions including heat shock proteins, toll-like receptor 4, and interleukin-12. Under both thermo-neutral and heat stress conditions, dietary brown rice improved the growth performance, decreased the immunoglobulin levels, and down-regulated the expression of splenic immune-related genes of broilers, although their systemic oxidative status was not affected. Dietary brown rice should be considered as a valuable component of broiler chicken feeds subjected to both thermo-neutral and heat stress conditions. The positive effects of brown rice on bird performance may be associated with the modulation of the immune responses, as reflected by the decreased production of immunoglobulins and altered splenic immune-related gene expression.