Lansoprazole-induced osteoporosis via the IP3R- and SOCE-mediated calcium signaling pathways

Abstract

Background Many clinical studies have shown a correlation between proton pump inhibitors (PPIs) and osteoporosis or fractures. The purpose of this study was to establish a murine model of chronic oral PPI administration to verify whether PPIs caused bone metabolic impairment and investigate the relevant molecular mechanism underlying the effects of PPIs on MC3T3-E1 murine osteoblasts. Methods A lansoprazole-induced bone loss model was used to investigate the damaging effects of PPIs. In vivo, immunohistochemistry, Hematoxylin–Eosin (HE) staining, micro-CT analysis, and blood biochemical analyses were used to evaluate the effect of lansoprazole on bone injury in mice. In vitro, the effects of lansoprazole and related signaling pathways in MC3T3-E1 cells were investigated by CCK-8 assays, EdU assays, flow cytometry, laser confocal microscopy, patch clamping, reverse transcription-quantitative polymerase chain reaction and Western blotting. Results After 6 months of lansoprazole gavage in ICR mice, the micro-CT results showed that compared with that in the vehicle group, the bone mineral density (BMD) in the high-dose group was significantly decreased (P < 0.05), and the bone microarchitecture gradually degraded. Biochemical analysis of bone serum showed that blood calcium and phosphorus were both decreased (P < 0.01). We found that long-term administration of lansoprazole impaired skeletal function in mice. In vitro, we found that lansoprazole (LPZ) could cause calcium overload in MC3T3-E1 cells leading to apoptosis, and 2-APB, an inhibitor of IP3R calcium release channel and SOCE pathway, effectively blocked increase in calcium caused by LPZ, thus protecting cell viability. Conclusions Longterm administration of LPZ induced osteoporotic symptoms in mice, and LPZ triggered calcium increases in osteoblasts in a concentration-dependent manner. Intracellular calcium ([Ca2+]i) persisted at a high concentration, thereby causing endoplasmic reticulum stress (ERS) and inducing osteoblast apoptosis.

Endoplasmic reticulum stress: a novel targeted approach to repair bone defects by regulating osteogenesis and angiogenesis

“…ER stress-mediated osteoblast apoptosis is driven by an increase in the intracellular Ca 2+ concentration [ 101 ]. An increased intracellular Ca 2+ disrupts Ca 2+ homeostasis, leading to Ca 2+ overload [ 102 ] and excessive ER stress103 and inducing osteoblast apoptosis [ 104 , 105 ]. Furthermore, micronutrients such as cadmium [ 106 ], fluorine [ 107 , 108 ], and iron [ 109 ] initiate the ER stress apoptosis pathway by increasing intracellular Ca 2+ .…”

Clinical Use of Lansoprazole and the Risk of Osteoporosis: A Nationwide Cohort Study

“…Therefore, PPI-related bone fragility might be determined by the impairment of the repair mechanisms for bone microfractures [6,7]. In particular, Cheng et al identified that lansoprazole, a commonly used PPI, could inhibit the P-type ATPases SERCA and Ca 2+ -ATPase, leading to an increase in Ca 2+ in osteoblasts and inducing endoplasmic reticulum stress and apoptosis; furthermore, blocking the increase in intracellular calcium had a significant protective effect against osteoblast apoptosis [8]. Data on the effect of PPIs on osteoporotic fracture risk have, however, been divergent.…”

PPI-Induced Changes in Plasma Metabolite Levels Influence Total Hip Bone Mineral Density in a UK Cohort

“…(12) A recent in vitro study using the mouse osteoblast cell line MC3T3-E1 showed that lansoprazole could lead to intracellular calcium overload, inducing endoplasmic reticulum stress and causing osteoblast apoptosis; moreover, 6-month treatment with lansoprazole in mouse models significantly decreased femoral BMD, in a dose-dependent manner. (13) Metabolomics is a promising agnostic tool to better understand metabolic changes induced by PPI use, and for identifying molecular biomarkers of PPI-mediated BMD loss. Several animal and human studies have been carried out to identify metabolites associated with low BMD and osteoporosis.…”

“…( 12 ) A recent in vitro study using the mouse osteoblast cell line MC3T3‐E1 showed that lansoprazole could lead to intracellular calcium overload, inducing endoplasmic reticulum stress and causing osteoblast apoptosis; moreover, 6‐month treatment with lansoprazole in mouse models significantly decreased femoral BMD, in a dose‐dependent manner. ( 13 )…”