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Strontium (Sr) belongs to the same group in the periodic table as calcium (Ca). Sr level can serve as an index of rumen Ca absorption capacity; however, the effects of Sr on Ca2+ metabolism are unclear. This study aims to investigate the effect of Sr on Ca2+ metabolism in bovine rumen epithelial cells. The bovine rumen epithelial cells were isolated from the rumen of newborn Holstein male calves (n = 3, 1 day old, 38.0 ± 2.8 kg, fasting). The half maximal inhibitory concentration (IC50) of Sr-treated bovine rumen epithelial cells and cell cycle were used to establish the Sr treatment model. Transcriptomics, proteomics, and network pharmacology were conducted to investigate the core targets of Sr-mediated regulation of Ca2+ metabolism in bovine rumen epithelial cells. The data of transcriptomics and proteomics were analyzed using bioinformatic analysis (Gene Ontology and Kyoto Encyclopedia of genes/protein). Quantitative data were analyzed using one-way ANOVA in GraphPad Prism 8.4.3 and the Shapiro–Wilk test was used for the normality test. Results presented that the IC50 of Sr treatment bovine rumen epithelial cells for 24 h was 43.21 mmol/L, and Sr increased intracellular Ca2+ levels. Multi-omics results demonstrated the differential expression of 770 mRNAs and 2436 proteins after Sr treatment; network pharmacology and reverse transcriptase polymerase chain reaction (RT-PCR) revealed Adenosylhomocysteine hydrolase-like protein 2 (AHCYL2), Semaphoring 3A (SEMA3A), Parathyroid hormone-related protein (PTHLH), Transforming growth factor β2 (TGF-β2), and Cholesterol side-chain cleavage enzyme (CYP11A1) as potential targets for Sr-mediated Ca2+ metabolism regulation. Together these results will improve the current comprehension of the regulatory effect of Sr on Ca2+ metabolism and pave a theoretical basis for Sr application in bovine hypocalcemia.

The trace element strontium has a significant impact on cartilage metabolism. However, the direct effects of strontium on alkaline phosphatase (ALP), a marker of bone growth, and bone morphogenetic protein-4 (BMP-4), which plays a key role in the regulation of bone and cartilage development, are not entirely clear. In order to understand the mechanisms involved in these processes, the chondrocytes were isolated from Wistar rat articular cartilage by enzymatic digestion and cultured under standard conditions. They were then treated with strontium at 0.5, 1.0, 2.0, 5.0, 20.0 and 100.0 μg/mL for 72 h. The mRNA abundance and protein expression levels of ALP and BMP-4 were measured using real-time polymerase chain reaction (real-time PCR) and Western blot analysis. The results showed that the levels of expression of ALP and BMP-4 in chondrocytes increased as the concentration of strontium increased relative to the control group, and the difference became significant at 1.0 μg/mL strontium (P

Strontium (Sr) can reduce cartilage degeneration and stimulate cartilage matrix formation. Angiogenesis plays a developmental role in chondrogenesis, and was stimulated by growth factors such as vascular endothelial growth factor (VEGF) and fibroblast growth factor 2 (FGF2). However, the direct influence of Sr on VEGF and FGF2 expressions in chondrocytes is not entirely clear. The objective of this study was to investigate the effects of different Sr concentrations on VEGF and FGF2 expressions in rat chondrocytes in vitro. Chondrocytes were isolated from Wistar rat articular by enzymatic digestion. As a Sr source, strontium chloride hexahydrate (SrCl2·6H2O) was added to the culture solution at final concentrations of 0, 0.5, 1.0, 2.0, 5.0, 20.0, and 100.0 μg/mL. After 72 h of continuous culture, mRNA abundance and protein expression levels of VEGF and FGF2 in the chondrocytes were determined by real-time polymerase chain reaction (real-time PCR) and Western blot, respectively. The results showed that VEGF and FGF2 expressions were dose-dependently elevated with Sr concentration in chondrocytes. The mRNA abundance and protein expression levels of VEGF were extremely significantly higher than those in the control group (P

The transforming growth factors β1 (TGF-β1) and TGF-β2, as two distinct homodimers of TGF-β superfamily, involve in chondrocyte growth and differentiation. Emerging evidence has implied that strontium (Sr) plays an important role in the bone formation and resorption, and has strong effects on stimulating human cartilage matrix formation in vitro. However, the direct effects of Sr on TGF-β1 and TGF-β2 expressions in chondrocytes are not entirely clear. The purpose of this study was to evaluate the influence of different Sr concentrations on the expression of TGF-β1 and TGF-β2 in rat chondrocytes in vitro. Chondrocytes were isolated from Wistar rat articular by enzymatic digestion. Strontium chloride hexahydrate (SrCl2·6H2O) was used as a Sr source in this study. Sr was added to the culture solution at final concentrations of 0, 0.5, 1.0, 2.0, 5.0, 20.0, and 100 μg/mL. After 72 h of continuous culture, TGF-β1 and TGF-β2 mRNA abundance and protein expression levels in the chondrocytes were determined by real-time polymerase chain reaction (real-time PCR) and Western blot, respectively. The results showed that TGF-β1 and TGF-β2 expressions in chondrocytes increased dose-dependently with Sr concentration. The mRNA abundance of TGF-β1 and TGF-β2 were markedly higher than those observed for control (P