Signal Transduction Of Mitochondrial Apoptotic Pathway During Autolysis Of Sea Cucumber

Sea cucumber belongs to Echinodermata. It is considered as highly nutritive and medicative. It contains protein, minerals, vitamins, a little fat, but without cholesterol. Sea cucumber is susceptible to environmental changes and factors including temperature, salt concentration, nutrient deficiency, exposure to sunlight, UV irradiation and showed body wall melting. This phenomenon is a major concern for sea cucumber production, particularly during transportation and processing.Previous studies found that the initial of sea cucumber melting phenomenon under certain circumstances may be attributed to apoptosis. Apoptosis has closely relationship with the family of Caspase. In this experiment we induce the autolysis of sea cucumber by ultraviolet rays radiation. The trichloroacetic acid(TCA) soluble peptide content was measured to observe the process of sea cucumber autolysis. The mitochondrial membrane potential changes of sea cucumber have been measured by JC-1 staining method during autolysis. Cleaved caspase-3 immunohistochemistry has been performed to observe the apoptosis. The specific activity changes of caspase-3, caspase-9 and other enzyme in sea cucumbers intestinal cells were determined during melting stage.The result showed that the mitochondrial membrane potential of sea cucumber intestines dropped immediately. Cleaved caspase-3 after immunohistochemical staining showed that the strongest phase at 0 h after UV inducing. Thereafter, the ratio of cleaved caspase-3 positive cells turned less, but the ratio of positive cells showed a small increasing in the later stages. The specific activity of caspase-3, caspase-9 and the other enzyme increased gradually after UVC exposure, but their activation form were different from each other.