Histopathology of laboratory-reared Nothobranchius fishes: Mycobacterial infections versus neoplastic lesions.
Iva DykováJakub ŽákMartin ReichardKamila SoučkováOndřej SlabýVojtěch BystrýRadim BlažekPublished in: Journal of fish diseases (2021)
Short-lived killifishes of the genus Nothobranchius Peters, 1868 (Cyprinodontiformes) are considered promising model organisms for biomedical research on ageing and tumorigenesis. We conducted histopathological analysis of 411 adult individuals from three Nothobranchius species to study details on spontaneous age-related neoplastic lesions. Light microscopy based on H&E and toluidine blue-stained sections revealed (a) non-proliferative liver changes with pronounced vacuolation of hepatocytes; (b) proliferation of kidney haemopoietic tissue contributing to excretory system damage; (c) proliferation of splenic mononuclear haemoblasts accompanied by reduced erythropoiesis; (d) proliferation of mononuclear cell aggregates in the liver parenchyma; and (e) rare occurrence of hepatocellular adenomas. Ziehl-Neelsen (ZN) staining revealed that the proliferative lesions are a host defence response to mycobacterial infections manifested by activation of the mononuclear phagocytic system and atypical granulomatous inflammatory reaction. 16S rRNA analysis identified three species of Mycobacterium in our samples. Our findings turn attention to lesions which mimic neoplasms by their gross appearance and question the light microscopic interpretation of lesions unless differential ZN staining is included. Beyond the limitations of our morphological approach, the intensity of mycobacterial infections is a challenging opportunity for research into the molecular-genetic background of the mononuclear phagocytic system reaction in Nothobranchius killifish.
Keyphrases
- mycobacterium tuberculosis
- peripheral blood
- signaling pathway
- single cell
- oxidative stress
- risk assessment
- heavy metals
- high resolution
- stem cells
- high throughput
- mesenchymal stem cells
- young adults
- working memory
- dna methylation
- multidrug resistant
- sensitive detection
- bone marrow
- liver injury
- drug induced
- data analysis