In vivo phagocytosis and hematology in Astyanax altiparanae, a potential model for surrogate technology

Modelling of macrophage responses to biomaterials in vitro: state-of-the-art and the need for the improvement

The increasing use of medical implants in various areas of medicine, particularly in orthopedic surgery, oncology, cardiology and dentistry, displayed the limitations in long-term integration of available biomaterials. The effective functioning and successful integration of implants requires not only technical excellence of materials but also consideration of the dynamics of biomaterial interaction with the immune system throughout the entire duration of implant use. The acute as well as long-term decisions about the efficiency of implant integration are done by local resident tissue macrophages and monocyte-derived macrophages that start to be recruited during tissue damage, when implant is installed, and are continuously recruited during the healing phase. Our review summarized the knowledge about the currently used macrophages-based in vitro cells system that include murine and human cells lines and primary ex vivo differentiated macrophages. We provided the information about most frequently examined biomarkers for acute inflammation, chronic inflammation, foreign body response and fibrosis, indicating the benefits and limitations of the model systems. Particular attention is given to the scavenging function of macrophages that controls dynamic composition of peri-implant microenvironment and ensures timely clearance of microorganisms, cytokines, metabolites, extracellular matrix components, dying cells as well as implant debris. We outline the perspective for the application of 3D systems for modelling implant interaction with the immune system in human tissue-specific microenvironment avoiding animal experimentation.

Effects of triploid induction on innate immunity and hematology in Astyanax altiparanae

Triploid induction is a promising biotechnique that could be used to enhance aquaculture yields in the near future. However, studies conducted with several fish species have demonstrated that the presence of an extra set of chromosomes may result in deleterious health effects. Furthermore, studies of fish immune responses still need to be conducted before these specimens can be readily commercialized. In the study presented herein, we evaluated the effects of triploid induction on hematology, erythrocyte morphometry and morphology, phagocytosis, and the expression levels of IL-1β and TGF-β using specimens of the Neotropical species, Astyanax altiparanae. In general, the cell counts of erythrocytes, leukocytes, and neutrophils in triploid fish were lower than those in diploid fish. The erythrocytes of triploid fish were larger than those found in diploid fish, but also demonstrated considerably higher frequencies of cellular and nuclear abnormalities. Although not statistically significant, triploid induction resulted in a phagocytic capacity (PC) 20% lower than that found with diploid fish. No notable differences were observed in phagocytic index (PI). Gene expression levels for the cytokine IL-1 were lower in tissues from the head kidney, liver, and spleen of triploid fish with respect to diploid fish. Gene expression levels of TGF-β were lower only in the spleen of triploids compared to diploids. In conclusion, triploid induction resulted in A. altiparanae specimens with immune impairments and potentially lower resistances to disease and low-quality environments.