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- Lordotic-kyphotic vertebrae develop ectopic cartilage-like tissue in Senegalese sole (Solea senegalensis)Publication . Cardeira Da Silva, João; Bensimon-Brito, A.; Pousão-Ferreira, P.; Cancela, Leonor; Gavaia, Paulo J.Lordosis and kyphosis are curvatures of the vertebral column that commonly affect Senegalese sole (Solea senegalensis) under intensive rearing conditions, constituting a problem for the aquaculture industry by increasing labor and operation costs and consequently reducing profits. However, no studies have yet addressed microanatomical changes in vertebral column curvature in this species. We have conducted histological analyses in order to determine the alterations at tissue and cellular levels in these deformities. Development of an ectopic cartilage-like tissue within bone matrix at the growth regions (contact area between two vertebrae) of affected vertebrae was observed in lordotic-kyphotic fish. As previously suggested, the increase in strain supported by deformed vertebrae may trigger the onset of metaplastic tissue formation through an osteochondroprogenitor precursor from the condensation of mesenchymal cells or by trans-differentiation of (pre-)osteoblastic cells to a chondrocytic lineage. The possibility of a notochord contribution, as well as the molecular events related to bone stress and bone types in terms of cellularity, are also discussed.
- Warfarin effects in the skeletal development of zebrafish (Danio rerio)Publication . Peres dos Santos, R.; Bensimon-Brito, A.; Gavaia, Paulo J.; Cancela, LeonorVitamin K-dependent gamma carboxylation (VKGC) is crucial for posttranslational modification of glutamate residues to form α-carboxy glutamic acid (Gla) in the presence of reduced vitamin K, molecular oxygen, and carbon dioxide (1). This modification has important implications, mainly physiological, like homeostasis, signal transduction and bone calcification. This mechanism ensures complete carboxylation of coagulation factors, and proteins like bone Gla protein (BGP) and matrix Gla protein (MGP), being essential for their biological activity. Warfarin is a known anticoagulant that inhibits the action of VKGC (2), inhibiting consequently the activity of the referred proteins.
- Skeletal development and performance of zebrafish Danio rerio (Hamilton, 1822) larvae and juvenile fish fed with different dietsPublication . Cardeira Da Silva, João; Dionísio, Gisela; Bensimon-Brito, A.; Cancela, Leonor; Gavaia, Paulo J.The appearance of skeletal deformities is a major problem associated to intensive, large-scale culture of fish species, affecting growth, development and ultimately, survival of produced fish. Although the mechanisms working behind it are still unclear, it is known that environmental, genetic and nutritional factors play fundamental roles. Given its importance as a vertebrate model to study skeleton-related diseases, the selection of an appropriate dietary protocol is a critical step in order to diminish the nutritional effect on bone and cartilage development.
- Matrix Gla protein expression: a complex process involving the use of alternative promoters, multiple splicing events and microRNAsPublication . Cancela, Leonor; Laizé, Vincent; Conceição, N.; Tiago, Daniel; Maia, Ana-Teresa; Bensimon-Brito, A.; Gavaia, Paulo J.Matrix Gla protein (MGP) is a secreted vitamin K-dependent protein (VKD) located in the extracellular matrix and capable of binding calcium through its -carboxyglutamate residues. Although identified in 1983, transcriptional and post-transcriptional mechanisms regulating its expression remain unclear.
- Effect of warfarin in zebrafish (Danio rerio) bone formation during caudal fin regenerationPublication . Dionísio, Gisela; Bensimon-Brito, A.; Gavaia, Paulo J.; Cancela, LeonorIn the last decade, fish has emerged as an important organism for studies on skeletal development in vertebrates, and evidence has been accumulated showing that zebrafish is a suitable system to perform phenotype-based drug screens. The ability to regenerate epidermal injuries is a general feature of most organisms yet only a few can fully regenerate severed appendages comprising several different tissues. Zebrafish is one of the most used models for regeneration studies, creating a powerful tool to study de novo bone formation without affecting vital development processes.