Based on previous cloning and sequencing study, real-time PCR and in situ hybridizationassays of the inflamed body wall of LPS-injected Ciona intestinalis showed the enhancedgene expression of a collagen with FACIT structural features (Ci-type IX-Col 1a-chain). Byusing specific antibodies raised against an opportunely chosen Ci-type IX-Col syntheticpeptide, the fibroblast property of hemocytes challenged in vitro with LPS (at 4 h) wasdisplayed by flow cytometry, while immunocytochemistry identified hemocytes with largegranules (morula cells) as collagen-producing cells. Hemocyte lysate supernatant analyzedin immunoblotting contained a 60 kDa band identifiable as 1a-chain-Ci-type IX-Col.Observations of body wall sections (immunohistochemistry method) supported the role ofhemocytes and showed that epidermis expressed Ci-type IX-Col 1a-chain in the time courseof the inflammatory reaction (within 24 h). Transcript and protein were mainly found in theepidermis that outlined the proximal side of the tunic matrix (at 24 h after LPS injection),in cells associated with the epidermis at 4 and 192 h. In conclusion, the C. intestinalisinflammatory response to LPS challenge appeared to be composed of a complex reactionset, and for the first time we showed in ascidians a granulation tissue with FACIT-collagenproduction that could participate in inflammation and wound healing. Like in vertebrates,C. intestinalis acute inflammatory reactions result in a regulated pattern of tissue repairwith collagen expression during remodelling. Ci-type IX-Col could be involved in a networkof non-fibril-forming collagens that participates in the organization of extracellular matrixand defense responses.
|Numero di pagine||11|
|Rivista||Developmental and Comparative Immunology|
|Stato di pubblicazione||Published - 2008|