Transcriptomic and Proteomic Analyses Reveal New Insights into Regulatory Mechanisms of Strontium in Bovine Chondrocytes

SIMPLE SUMMARY: Strontium (Sr) is one of the essential microelements of the body, which mainly exists in the bone. Sr has been demonstrated to affect the formation of bone by regulating the development of cattle chondrocytes, which make cartilage. However, the molecular mechanism by which Sr regulates the growth of bovine chondrocytes is unknown. In this study, we investigated 111 differentially expressed genes and 286 differentially expressed proteins. Sr was involved in pathways related to proliferation and differentiation of chondrocytes, fat metabolism, the inflammation process, and immune responses of chondrocytes. This study described the potential regulatory mechanism of Sr in bovine chondrocytes and provided new insights into the functions and application of Sr in ruminants. ABSTRACT: Strontium (Sr) is a trace element found mainly in bone, and it performs a dual action by promoting bone formation and inhibiting bone resorption. Sr has been used to evaluate the gastrointestinal calcium (Ca) absorption capacity of dairy cows due to the similar physicochemical properties of the two elements. However, the possible effects of Sr on dairy cows remain unclear. This study aimed to explore the potential regulatory mechanism of Sr in bovine chondrocytes by performing transcriptomic and proteomic analyses. A total of 111 genes (52 up-regulated and 59 down-regulated) were identified as significantly altered (1.2-fold change and p < 0.05) between control and Sr-treated groups. Moreover, LC-MS-based proteomic analysis detected 286 changed proteins (159 up-regulated and 127 down-regulated) between the control and Sr-treated groups (1.2-fold change and p < 0.05). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations of a combination analysis of the transcriptomic and proteomic data revealed that the genes were predominantly involved in chondrocyte proliferation and differentiation, fat metabolism, the inflammation process, and immune responses. Overall, our data reveal a potential regulatory mechanism of strontium in bovine chondrocytes, thus providing further insights into the functions and application of Sr in ruminants.