Inflammatory Injury and Mitophagy in the Cock Heart Induced by the Oral Administration of Hexavalent Chromium

Abstract

As a highly toxic heavy metal, chromium has caused a certain threat to public health and livestock breeding in recent years. In poultry, as one of our most commonly consumed meat product, its health issues will seriously threaten the safety of human life. As previous studies have confirmed, when cells are stimulated by the external environment, mitochondria, as an organelle that provides energy to the cells, can cause damage and autophagy. The purpose of this study is to confirm whether Cr(VI) can cause mitophagy in cock heart. We first randomly divided 32 cocks into four groups to explore the mechanism of this effect. The cocks were then separately exposed to four different dose levels, namely, the control level and 10, 30, and 50 mg/kg levels, via daily oral intake into the body through mixed feeding for 45 days. After 45 days, we sampled and detected pathological changes and the levels of inflammatory factors (IL-6, TNF-α, and IFN-γ), mitochondrial membrane potential (MMP), adenosine triphosphatases (ATPases), and mitophagy-related proteins (LC3, p62/SQTM1, TOMM20, and Parkin). We found that IL-6, TNF-α, IFN-γ, and LC3II contents increased with the increase in Cr(VI) concentration. However, MMP, ATPases, p62/SQTM1, and TOMM20 levels decreased with the increase in Cr(VI) concentration. At the same time, Cr(VI) exposure caused heart tissue damages and Parkin translocation. In conclusion, our results proved that inflammatory damage, mitochondrial function damage, and mitophagy in cock heart tissues were dependent on Cr(VI) concentration.

Keywords: Cock; Cr(VI); Heart; Inflammatory injury; Mitophagy.