Research of immune system and vitamin A role on serum amyloid A production in chicken embryo fibroblast cell culture induced with lipopolysaccharide (LPS) by molecular techniques

Leg diseases in poultry cause various health problems and adversely affect animal welfare. Amyloid arthropathy, one of these leg diseases, is a pathological phenomenon that occurs when amyloid A (AA) protein accumulates in the leg joints of brown layer hens and serum amyloid A (SAA), the precursor of AA protein, forms permanent amyloid fibrils. The aim of this thesis study was to evaluate the production of precursor protein SAA at 24 and 48 hours by enzyme-linked immunosorbent test (ELISA) and real-time quantitative polymerase chain reaction (qPCR) after the induction of chicken embryonic synovial fibroblasts (CESF) with different doses of lipopolysaccharide (LPS), interleukin-1β (IL-1β) and vitamin A. In the study, for the first time, a suitable cell culture system such as primary culture, passage and characterization of CESFs isolated from brown layer hen embryos was created, and immunocytochemistry, hemacolor staining and carbon phagocytosis test were used to characterize the isolated CESFs. According to the results, a statistically significant increase was observed in SAA mRNA expression with qPCR in all groups except the group induced with vitamin A for 48 hours, while no significant increase was found in the SAA level in the culture medium with ELISA. Our findings have shown that SAA expression in CESFs is particularly dependent on LPS concentration, with IL-1β and vitamin A having less effect on SAA expression. It has also been observed that CESFs from brown layer hen embryos represent a suitable study model for amyloid arthropathy.