The modulation of matrix metalloproteinase and ADAM gene expression in human chondrocytes by interleukin-1 and oncostatin M: a time-course study using real-time quantitative reverse transcription-polymerase chain reaction.

OBJECTIVE: Previous studies have reported elevated levels of interleukin-1 (IL-1) and oncostatin M (OSM) in rheumatoid joints, as well as the synergistic degradation of human articular cartilage by this cytokine combination. The present study was undertaken to investigate the ability of IL-1 and OSM to modulate gene expression of matrix metalloproteinase (MMP), ADAM, and ADAM-TS (ADAM with thrombospondin motifs) family members in human chondrocytes. METHODS: T/C28a4 human chondrocytes were stimulated for 2-48 hours with IL-1 and/or OSM. Total RNA was harvested, reverse transcribed, and assessed by real-time polymerase chain reaction for the expression of various MMP, ADAM, and ADAM-TS messenger RNAs (mRNA). Results were normalized to 18S ribosomal RNA. RESULTS: IL-1 and OSM synergized to markedly induce the expression of the collagenases MMP-1, MMP-8, and MMP-13 as well as MMP-3, an activator of proMMPs. Expression of mRNA for MMPs 1, 3, and 13 was induced early, whereas that of MMP-8 mRNA occurred late. Gene expression of MMP-14, an MMP that degrades collagen and activates proMMP-13, was elevated by this combination. IL-1 and OSM also synergized to induce gene expression of the aggrecanase ADAM-TS4, but not ADAM-TS5. CONCLUSION: These data indicate that the potent cartilage-degrading properties of the combination of IL-1 and OSM are potentially mediated by a synergistic induction of the aggrecan-degrading enzyme ADAM-TS4 and the collagen-degrading enzymes MMP-1, MMP-8, MMP-13, and MMP-14, although differences in the magnitude of response and in the time course of induction were observed. A role for MMPs 3 and 14 in the activation of proMMPs may also be implicated.

Temporal and spatial genetic variation in spawning grounds of European hake (Merluccius merluccius) in the Bay of Biscay.

Polymorphism at five microsatellite loci were screened to determine the genetic variability and the temporal stability of population structure in natural populations of European hake (Merluccius merluccius, L.) within the Bay of Biscay. In addition, the control region (900 bp) and two protein coding genes (ATPase, subunits 6 and 8, 842 bp and a partial sequence of the ND1, 800 bp) of the mitochondrial DNA (mtDNA) were sequenced from geographically distant populations from the extremes of the species range. One hundred individuals from either side of a supposed stock boundary within the bay were collected in autumn 1997. This sampling strategy was repeated during hake spawning seasons in late spring of 1998 and 1999. Low levels of population subdivision were found between putative populations within years. Similarly, low levels of differentiation were found between autumn 1997 northern samples and spring 1998 southern samples which were collected 7 months later on spawning grounds. These results are discussed in relation to ecological, behavioural and oceanographic information. Sampling effects, which may influence these results, are also discussed. Theta (theta) estimates were significantly different from zero in every other pairwise comparison between geographical areas (north and south of the Bay of Biscay) and between years within the same area (P<0.05). Hierarchical analysis of molecular variance (AMOVA) does not confirm the temporal persistence of population structure. These results are discussed in relation to variance in reproductive success, and temporal spawning patterns, which may exist within the bay. mtDNA variability was very low between geographically distant samples from Norway and the Mediterranean Sea with only 10 variable sites found in a total of 2542 bp of mtDNA, these differences being exclusively in the D-loop.

Macrogeographical population differentiation in oceanic environments: a case study of European hake (Merluccius merluccius), a commercially important fish.

Polymorphism at six microsatellite loci was used to study genetic variability and population structure in six geographically distant natural populations of European hake (Merluccius merluccius L.). Four hundred and eighty-three individuals were sampled from Trondheimsfjord in Norway, the Celtic Sea, the southern Bay of Biscay, Faro off Portugal, the Mediterranean Sea north of the coast of Tunisia and the Adriatic Sea. Population subdivision was found between Mediterranean and Atlantic samples, theta = 0.029 (P < 0. 001). No substructuring was found between samples within the Mediterranean Sea, theta = 0.003 and RST = 0.007 (P > 0.05). The Atlantic population structure appears to be more complex than previously suggested by the placement of stock boundaries by the International Council for the Exploration of the Seas (ICES). Analyses based on various models of microsatellite evolution all suggest that differentiation exists between Bay of Biscay and Portugese samples, theta = 0.013 (P < 0.001), RST = 0.036 (P < 0. 001) which are currently managed as one stock. By contrast, fixation indices indicated no differentiation between southern Bay of Biscay samples and Celtic Sea samples, theta = 0.003 (P = 0.02), phiST = 0. 007 (P = 0.10) which are managed as separate stocks. These results suggest that if the observed trends are stable through time, current management policy of European hake may need revision.