# Serum amyloid a production in chicken embryonic synovial fibroblasts induced by lipopolysaccharide, interleukin-1β, and vitamin A

## TL;DR

This study shows how chicken embryonic synovial fibroblasts produce SAA when exposed to LPS, IL-1β, and vitamin A, which may help understand amyloid arthropathy in hens.

## Contribution

The study identifies LPS as the most effective inducer of SAA in chicken embryonic synovial fibroblasts for amyloid arthropathy research.

## Key findings

- SAA mRNA expression increased significantly in all groups except the vitamin A-induced 48-hour group.
- LPS (10 μg/mL) + IL-1β (30 ng/mL) caused the highest SAA expression increase in 24-hour groups.
- LPS (5 μg/mL) + IL-1β (50 ng/mL) + vitamin A caused the highest SAA expression increase in 48-hour groups.

## Abstract

Amyloid arthropathy, which negatively affects animal welfare by causing various health problems in brown laying hens, is a pathological phenomenon that occurs when amyloid A (AA) protein accumulates in the leg joints and serum amyloid A (SAA), the precursor of AA protein, forms permanent amyloid fibrils. This study aimed to evaluate the SAA production at the 24th and 48th h by enzyme-linked immunosorbent antibody assay (ELISA) in culture medium 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. Hemacolor staining, immunocytochemistry, and carbon powder uptake test were performed to characterize the isolated CESF in the study. A statistically significant increase was observed in SAA mRNA expression in all groups at the 24th and 48th h, except the group induced with vitamin A for 48 h, while no increase was detected in the SAA level by ELISA. In the qPCR results, the highest increase among the 24-hour groups was 2604.5 ± 476 in the LPS (10 μg/mL) + IL-1β (30 ng/mL) applied group, while the highest increase among the 48-hour groups was 1577.4 ± 326.4 in the LPS (5 μg/mL) + IL-1β (50 ng/mL) + Vitamin A applied group. The results have shown that SAA expression in CESF is particularly dependent on LPS concentration, with IL-1β and vitamin A being less effective CESF from the brown layer hen embryos proved to be a suitable study model for amyloid arthropathy.