Role of water-soluble matrix fraction, extracted from the nacre of Pinctada maxima, in the regulation of cell activity in abalone mantle cell culture (Haliotis tuberculata).

In mollusks, the mantle is responsible for the secretion of an organic matrix that mineralizes to form the shell. A model of mantle cell culture has been established from the nacreous gastropod Haliotis tuberculata. First, viability of cells, quantified by the MTT (3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide) reduction assay, was monitored in order to determine a cell density and a time-culturing period in order to investigate biomineralization processes in vitro. During the first 11 days of culture, an increase of MTT response demonstrated an activation of cultured cells mitochondrial activity as confirmed by the total protein content assay. The effect of a water-soluble extract from the organic matrix of Pinctada maxima (WSM) was tested on this cell culture system for 11 days-period exposure. WSM reduced the global viability of mantle cells in a dose-dependent way which corresponded to a cell death. Alkaline phosphatase activity normalized to total protein content increased in the presence of WSM. This increase may be due to an activation of cells and a selection of one (or a few) cell type(s). Further investigations will help us to determine this selectivity issue.