Deoxynivalenol interferes with intestinal motility via injuring the contractility of enteric smooth muscle cells: A novel hazard to the gastrointestinal tract by environmental toxins

Deoxynivalenol (DON) is a prevalent Fusarium mycotoxin, occurs predominantly in the global environment, especially in cereals, animal feed and food commodities. The widespread contamination causes a serious risk to human and animal health. DON usually impairs weight gain, which is presumably from its capacity to reduce feed intake by interfering with intestinal motility. To clarify the role of smooth muscle cells (SMCs) contractility in intestinal motility and growth inhibition caused by DON, twelve weaned piglets were firstly divided into two groups to feed control or Fusarium mycotoxin-contaminated (MC) diet. Results showed that the final body weight, average daily gain and average daily feed intake were significantly reduced in piglets fed the MC diet. Exposure to the MC diet also significantly decreased the thickness of smooth muscle layer and SMCs contractile markers expression (myosin heavy chain 11, smooth muscle actin gamma 2, transgelin, calponin 1) in jejunum and ileum of piglets. Furthermore, oral DON supplementation (3 mg/kg body weight) to mice in six consecutive days could significantly inhibit the upper intestinal transit, impede normal defecation and downregulate SMCs contractile markers expression in small intestine. Finally, we generated a porcine enteric smooth muscle cell line (PISMC), and found that DON could depress its contractility by decreasing PISMC proliferation, migration and contractile markers expression. In conclusion, these findings in vivo and in vitro suggest that DON, as a common environmental toxin, can not only reduce proliferative and motile phenotype, but also decrease contractile apparatus components (contractile markers expression) in SMCs, which in turn influences SMCs contractility and then interferes with intestinal motility and growth performance