Effects of Acute Heat Stress on a Newly Established Chicken Hepatocyte-Nonparenchymal Cell Co-Culture Model

• Published in: Animals (Basel) 2020-03, Vol.10 (3), p.409
• Main Authors: Mackei, Máté, Molnár, Andor, Nagy, Szabolcs, Pál, László, Kővágó, Csaba, Gálfi, Péter, Dublecz, Károly, Husvéth, Ferenc, Neogrády, Zsuzsanna, Mátis, Gábor
• Format: Article
• Language: English
• Subjects: Animal health; broiler chicken; Carbon dioxide; Cell culture; Cellular stress response; Centrifugation; Chickens; Environmental aspects; Enzymatic activity; Enzyme activity; Exposure; Flow cytometry; Gene expression; Heat; Heat shock proteins; Heat stress; Heat stress disorders; Heat tolerance; Hepatocytes; Homeostasis; Hsp70 protein; Hydrogen peroxide; Immunocytochemistry; Inflammation; Interleukin 6; Interleukin 8; Liver; Macrophages; Metabolic rate; Metabolism; Mimicry; Oxidative stress; Physiological aspects; Poultry; pro-inflammatory cytokines; Protein biosynthesis; Protein synthesis; Proteins; Sediments; Stress response
• ISSN: 2076-2615; 2076-2615
• DOI: 10.3390/ani10030409

Heat stress is one of the most important issues in broiler flocks impairing animal health and productivity. On a cellular level, excess heat exposure can trigger heat shock response acting for the restoration of cell homeostasis by several mechanisms, such as affecting heat shock protein synthesis, redox homeostasis and pro-inflammatory cytokine production. The major aim of this study was to establish a novel avian hepatocyte-nonparenchymal cell co-culture as a model for investigating the cellular effects of heat stress and its interaction with inflammation in chicken liver. Cell fractions were isolated by differential centrifugation from a freshly perfused chicken liver, and hepatocyte mono-cultures as well as hepatocyte-nonparenchymal cell co-cultures (with cell ratio 6:1, hepatocytes to nonparenchymal cells, mimicking a milder hepatic inflammation) were prepared. Isolated and cultured cells were characterized by flow cytometry and immunocytochemistry applying hepatocyte- and macrophage-specific antibodies. Confluent cell cultures were exposed to 43 °C temperature for 1 or 2 h, while controls were cultured at 38.5 °C. The metabolic activity, LDH enzyme activity, reactive oxygen species (H O ) production, extracellular concentration of heat shock protein 70 (HSP70), and that of the pro-inflammatory cytokines interleukin (IL-)6 and IL-8 were assessed. Shorter heat stress applied for 1 h could strongly influence liver cell function by significantly increasing catabolic metabolism and extracellular H O release, and by significantly decreasing HSP70, IL-6, and IL-8 production on both cell culture models. However, all these alterations were restored after 2 h heat exposure, indicating a fast recovery of liver cells. Hepatocyte mono-cultures and hepatocyte-nonparenchymal cell co-cultures responded to heat stress in a similar manner, but the higher metabolic rate of co-cultured cells may have contributed to a better capability of inflamed liver cells for accommodation to stress conditions. In conclusion, the established new primary cell culture models provide suitable tools for studying the hepatic inflammatory and stress response. The results of this study highlight the impact of short-term heat stress on the liver in chickens, underline the mediatory role of oxidative stress in acute stress response, and suggest a fast cellular adaptation potential in liver cells.