Correlated expression profile of extracellular matrix-related molecules during the inflammatory response of the teleost fish gilthead seabream.

Extracellular matrix (ECM) components, in addition to their structural functions, interact with cell surface receptors and intracellular components to modulate the transduction of signals for cell growth, differentiation, migration, proliferation, polarization, apoptosis and inflammation. Our previous findings in the gilthead seabream (Sparus aurata L.), a marine seasonal hermaphrodite teleost fish, have shown that both endocrine and immune stimuli modulate the expression of matrix metalloproteases (MMPs) and tissue inhibitors of MMP (TIMPs). In addition, collagen type I (COL1) induces the expression of some pro-inflammatory cytokines and MMPs in professional phagocytes. Consequently, in this study we use real-time RT-PCR to analyze the gene expression profile of several ECM-related molecules (MMP-2, -9 and -13, TIMP-2a, and -2b, COL1A1, and integrin beta1a) in different organs of adult specimens as well as in response to innate immune challenges. Our results showed that liver had the lowest basal levels of them, although they were clearly modulated during injury and infection. In the same way, ECM-related molecules seem to participate in pro-inflammatory processes, being of particular interest COL1 which is synthesized by immune cells and is able to act as autocrine/paracrine stimulus for them. Lastly, we propose that the observed correlations between ECM-related molecules during the inflammatory response should be considered to obtain a more accurate picture of their roles in this process.