Study of the distribution of active caspase-3-positive cells in turbot, Scophthalmus maximus (L.), enteromyxosis.
Enteromyxosis caused by Enteromyxum scophthalmi is one of the parasitizations with a higher economic impact on turbot, Scophthalmus maximus (L.), aquaculture. This myxosporean produces severe catarrhal enteritis with abundant inflammatory infiltrates in the lamina propria-submucosa (LP), epithelial detachment and leucocyte depletion of the lymphohaematopoietic organs. Some advances made on the pathogenesis pointed to a role of apoptosis in the enteromyxosis. Therefore, the main aim of this work was to employ the TUNEL assay and the anti-(active caspase-3) immunohistochemical assay to detect apoptotic cells in both healthy and E. scophthalmi-infected turbot in order to establish the presence and distribution of apoptotic cells during development of the disease. More apoptotic cells located within the gastrointestinal epithelium were observed in the initial stages of the infection in E. scophthalmi-infected turbot compared with non-infected turbot. As the infection progressed, a higher degree of apoptosis occurred in the epithelium of folds heavily parasitized. In the severely infected turbot, apoptosis was also found among the leucocytes of the intestinal inflammatory infiltrates. Moreover, the number of active caspase-3-positive cells in the lymphohaematopoietic organs tended to increase with disease severity. In view of the results, increased apoptosis in the epithelium may favour the scaling that occurs during enteromyxosis and cell death of leucocytes in the intestinal LP, contributing to leucocyte depletion in severe cases.
Departamento de Ciencias Clínicas Veterinarias, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo, Spain.
A P
AP
Losada
R
R
Bermúdez
L D
LD
Faílde
M V
MV
Ruiz de Ocenda
M I
MI
Quiroga
D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism*; D005393:Fish Diseases / Q000201:enzymology* / Q000401:mortality / Q000473:pathology; D005412:Flatfishes / Q000469:parasitology*; D041981:Gastrointestinal Tract / Q000469:parasitology / Q000473:pathology; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D007413:Intestinal Mucosa / Q000469:parasitology / Q000473:pathology; D007962:Leukocytes / Q000473:pathology; D055764:Myxozoa / Q000502:physiology; D010273:Parasitic Diseases, Animal / Q000201:enzymology* / Q000401:mortality / Q000473:pathology
D053148:Caspase 3
Enteromyxum scophthalmi; Scophthalmus maximus; apoptosis; caspase-3; turbot