Iron accumulation induces reactive oxide species to inhibits mesenchymal stem cells and osteogenesis via nicotinamide adenine dinucleotide phosphate reduced oxidase 4 activation

Abstract

Objective To study iron accumulation affect on mesenchymal stem cells (MSCs), and to explore iron accumulation in MSCs level pathogenesis. Methods In vivo, 6-8 weeks C57 male mice were devived into control group and experimental group, the experimental group was intraperitoneally injected with ferric ammonium citrate (FAC) of 0.1 g/kg/week intervention in eight weeks, the two groups were tested: serum ferritin (FER), osteogenesis markers procollagen type 1 amino-terminal propeptide (P1NP), distal femur trabecular bone reconstruction of three dimensional form and spatial structure parameter, MSCs accounted for the proportion of bone marrow cells. In vitro, 6-8 weeks male C57 mice bone marrow tissue were separation, MSCs were cultivated and devided after reaching a certain number in the control group and experimental group. After 24 h FAC intervention in experimental group, two groups were tested: reactive oxygen species (ROS), nicotinamide adenine dinucleotide phosphate reduced oxidase 4 (NOX4) expression level. Statistical analyses were performed. Results FAC group serum FER [(14.72±0.97) μg/L] was elevated compared to control group [(4.92±0.82) μg/L], P=0.002. FAC group bone marrow MSCs [(2.08±0.98)%] was reduced compared to control group [(3.98±0.82%)%], P=0.004. FAC group MSCs ROS mean value (56.26±8.36) was exceed to control group (257.65±12.69), P=0.000; MSCs NOX4 cell protein was increased compared with the control group; Osteogenesis index P1NP in FAC group [(4.81±0.51) ng/ml] was decreased compared to control group [(10.06±0.96) ng/ml], P=0.001. The micro-CT detection of bone mineral density in FAC group [(53.12±9.86) mg/mm3] was decreased compared to control group [(103.76±7.92) mg/mm3]. FAC group spatial structure parameter showed bone volume/ tissue volume (BV/TV): [(11.23±1.86)%] was decreased compared to control group [(18.63±2.02)%], P=0.002; FAC group trabecular thickness (Tb. Th): [(0.057±0.018) mm] was decreased to control group [(0.083±0.006) mm], P=0.003; FAC group trabecular number (Tb. N): [(0.92±0.22) N/mm] was decreased compared to control group [(1.25±0.18) N/mm], P=0.004. Conclusion The osteogenetic activity is restrained after iron accumulation may be associated with increased MSCs ROS, MSCs ROS increased may be related to iron accumulation induced NOX4 activation. Key words: Iron accumulation; Mesenchymal stem cells; Osteoporosis; Reactive oxide species