Proteomic Insights into Molybdenum-Induced Pancreatic Injury in Goats

Molybdenum (Mo) is an essential trace element, but excessive exposure may exert toxic effects in ruminants. The pancreas plays a central role in post-ruminal digestion, yet the effects of high Mo exposure on pancreatic digestive function and its underlying mechanisms in goats remain unclear. This study investigated the effects of chronic Mo exposure on pancreatic function in goats through physiological assessment and proteomic analysis. Twenty Yudong Black goats (six months old, 22.34 ± 1.87 kg) were randomly assigned to a control group or a Mo group (n = 10 each). Goats in the Mo group were fed a basal diet supplemented with 50 mg·kg⁻¹ Na₂MoO₄·2H₂O for 60 days. Body weight, pancreatic organ index, and the activities of pancreatic amylase, lipase, and trypsin were measured. Tandem mass tag (TMT)-based quantitative proteomics was performed on pancreatic tissue. High Mo exposure significantly reduced body weight gain, increased the pancreatic organ index, and decreased pancreatic exocrine enzyme activities. Proteomic analysis identified 765 differentially expressed proteins, including 568 upregulated and 197 downregulated proteins. These proteins were mainly enriched in pathways related to immune and inflammatory responses, cytoskeletal organization, phagocytosis, amino acid metabolism, and lysosome-associated processes. Protein-protein interaction analysis identified VCL, RAC2, ITGB2, and TLN1 as key hub proteins. Parallel reaction monitoring validation confirmed trends consistent with the TMT results. Overall, chronic high Mo exposure impairs pancreatic exocrine digestive function and induces broad proteomic alterations, providing new insight into the molecular mechanisms of Mo-induced pancreatic injury in goats.