During chronic kidney disease (CKD),alterations in bone and mineral metabolism include increased production of the hormone fibroblast growth factor 23 (FGF23) that may contribute to cardiovascular mortality.The osteoc...During chronic kidney disease (CKD),alterations in bone and mineral metabolism include increased production of the hormone fibroblast growth factor 23 (FGF23) that may contribute to cardiovascular mortality.The osteocyte protein dentin matrix protein 1 (DMP1) reduces FGF23 and enhances bone mineralization,but its effects in CKD are unknown.We tested the hypothesis that DMP1 supplementation in CKD would improve bone health,prevent FGF23 elevations and minimize consequent adverse cardiovascular outcomes.We investigated DMP1 regulation and effects in wild-type (WT) mice and the Col4a3^-/- mouse model of CKD.Col4a3^-/- mice demonstrated impaired kidney function,reduced bone DMP1 expression,reduced bone mass,altered osteocyte morphology and connectivity,increased osteocyte apoptosis,increased serum FGF23,hyperphosphatemia,left ventricular hypertrophy (LVH),and reduced survival.Genetic or pharmacological supplementation of DMP1 in Col4a3^-/- mice prevented osteocyte apoptosis,preserved osteocyte networks,corrected bone mass,partially lowered FGF23 levels by attenuating NFAT-induced FGF23 transcription,and further increased serum phosphate.Despite impaired kidney function and worsened hyperphosphatemia,DMP1 prevented development of LVH and improved Col4a3^-/- survival.Our data suggest that CKD reduces DMP1 expression,whereas its restoration represents a potential therapeutic approach to lower FGF23 and improve bone and cardiac health in CKD.展开更多
Bone-produced fibroblast growth factor 23(FGF23)increases in response to inflammation and iron deficiency and contributes to cardiovascular mortality in chronic kidney disease(CKD).Neutrophil gelatinase-associated lip...Bone-produced fibroblast growth factor 23(FGF23)increases in response to inflammation and iron deficiency and contributes to cardiovascular mortality in chronic kidney disease(CKD).Neutrophil gelatinase-associated lipocalin(NGAL or lipocalin 2;LCN2 the murine homolog)is a pro-inflammatory and iron-shuttling molecule that is secreted in response to kidney injury and may promote CKD progression.We investigated bone FGF23 regulation by circulating LCN2.At 23 weeks,Col4a3KO mice showed impaired kidney function,increased levels of kidney and serum LCN2,increased bone and serum FGF23,anemia,and left ventricular hypertrophy(LVH).Deletion of Lcn2 in CKD mice did not improve kidney function or anemia but prevented the development of LVH and improved survival in association with marked reductions in serum FGF23.Lcn2 deletion specifically prevented FGF23 elevations in response to inflammation,but not iron deficiency or phosphate,and administration of LCN2 increased serum FGF23 in healthy and CKD mice by stimulating Fgf23 transcription via activation of cAMP-mediated signaling in bone cells.These results show that kidney-produced LCN2 is an important mediator of increased FGF23 production by bone in response to inflammation and in CKD.LCN2 inhibition might represent a potential therapeutic approach to lower FGF23 and improve outcomes in CKD.展开更多
基金supported by grants to A.M.(R01DK101730),V.D.(R01DK102815,R01DK114158),and M.W.(R01DK076116)from National Institute of Health
文摘During chronic kidney disease (CKD),alterations in bone and mineral metabolism include increased production of the hormone fibroblast growth factor 23 (FGF23) that may contribute to cardiovascular mortality.The osteocyte protein dentin matrix protein 1 (DMP1) reduces FGF23 and enhances bone mineralization,but its effects in CKD are unknown.We tested the hypothesis that DMP1 supplementation in CKD would improve bone health,prevent FGF23 elevations and minimize consequent adverse cardiovascular outcomes.We investigated DMP1 regulation and effects in wild-type (WT) mice and the Col4a3^-/- mouse model of CKD.Col4a3^-/- mice demonstrated impaired kidney function,reduced bone DMP1 expression,reduced bone mass,altered osteocyte morphology and connectivity,increased osteocyte apoptosis,increased serum FGF23,hyperphosphatemia,left ventricular hypertrophy (LVH),and reduced survival.Genetic or pharmacological supplementation of DMP1 in Col4a3^-/- mice prevented osteocyte apoptosis,preserved osteocyte networks,corrected bone mass,partially lowered FGF23 levels by attenuating NFAT-induced FGF23 transcription,and further increased serum phosphate.Despite impaired kidney function and worsened hyperphosphatemia,DMP1 prevented development of LVH and improved Col4a3^-/- survival.Our data suggest that CKD reduces DMP1 expression,whereas its restoration represents a potential therapeutic approach to lower FGF23 and improve bone and cardiac health in CKD.
基金supported by grants from the National Institute of Health to V.D.(R01DK102815,R01DK114158)A.M.(R01DK101730).
文摘Bone-produced fibroblast growth factor 23(FGF23)increases in response to inflammation and iron deficiency and contributes to cardiovascular mortality in chronic kidney disease(CKD).Neutrophil gelatinase-associated lipocalin(NGAL or lipocalin 2;LCN2 the murine homolog)is a pro-inflammatory and iron-shuttling molecule that is secreted in response to kidney injury and may promote CKD progression.We investigated bone FGF23 regulation by circulating LCN2.At 23 weeks,Col4a3KO mice showed impaired kidney function,increased levels of kidney and serum LCN2,increased bone and serum FGF23,anemia,and left ventricular hypertrophy(LVH).Deletion of Lcn2 in CKD mice did not improve kidney function or anemia but prevented the development of LVH and improved survival in association with marked reductions in serum FGF23.Lcn2 deletion specifically prevented FGF23 elevations in response to inflammation,but not iron deficiency or phosphate,and administration of LCN2 increased serum FGF23 in healthy and CKD mice by stimulating Fgf23 transcription via activation of cAMP-mediated signaling in bone cells.These results show that kidney-produced LCN2 is an important mediator of increased FGF23 production by bone in response to inflammation and in CKD.LCN2 inhibition might represent a potential therapeutic approach to lower FGF23 and improve outcomes in CKD.
