title: Dietary calcium deficiency and excess both impact bone development and mesenchymal stem cell lineage priming in neonatal piglets.
abstract: BACKGROUND
  Optimizing calcium nutrition to maximize bone accretion during growth to prevent fragility fractures later in life has spurred greater interest in calcium nutrition in neonates.
  
  
  OBJECTIVE
  The aim of this study was to determine the effect of dietary calcium, from deficiency through excess, on bone growth, and the in vivo and in vitro behavior of mesenchymal stem cells (MSCs) in neonatal pigs.
  
  
  METHODS
  Twenty-four male and female piglets (24 ± 6 h old) were fed either a calcium-deficient [Ca-D; 0.6% Ca on a dry matter (DM) basis], a calcium-adequate diet (Ca-A; 0.9% Ca on a DM basis), or a calcium-excessive diet (Ca-E; 1.3% Ca on a DM basis) for 14 d to assess the impact of dietary calcium on calcium homeostasis and on the behavior of MSCs.
  
  
  RESULTS
  Growth rate was not affected by the Ca-E diet, although bone ash content was 16% higher (P < 0.05) and urinary calcium excretion was 5-fold higher, when normalized to creatinine, compared with the Ca-A group at trial completion. Serum parathyroid hormone (PTH) concentrations were elevated (P < 0.05) in Ca-D piglets in comparison with other groups at both 7 and 14 d. In vivo proliferation of MSCs was 30% higher (P < 0.05) in Ca-E piglets than the other groups. MSCs from both Ca-D- and Ca-E-fed piglets had greater adipogenic potential based on increased gene expression (P < 0.05) of peroxisome proliferator-activated receptor γ (Pparg) and adipocyte fatty acid-binding protein (Ap2) than MSCs from Ca-A piglets. Interestingly, only MSCs from Ca-E-fed piglets had greater (P < 0.05) gene expression of lipoprotein lipase (Lpl) during adipocytic differentiation than those from Ca-A piglets. To assess alterations in lineage allocation and priming, the most and least osteogenic (O+ and O-, respectively) and adipogenic (A+ and A-, respectively) colonies from each MSC isolation were selected on the basis of functional staining. The O+ colonies from Ca-D piglets expressed lower (P < 0.05) levels of osteocalcin (OC) mRNA than did those from other groups, whereas the O- colonies from Ca-E piglets expressed higher (P < 0.05) levels of mRNA of Pparg, Ap2, and Lpl than did those from other groups.
  
  
  CONCLUSIONS
  Neonatal calcium deficiency appears to reduce the osteogenic priming of MSCs while enlarging a subpopulation of potentially adipogenic cells, and excess dietary calcium appears to allow greater multipotency of MSCs. These programming alterations of MSCs could have long-term consequences for bone health.
authors.affiliation: Laboratory of Developmental Nutrition, Department of Animal Science, North Carolina State University, Raleigh, NC.
authors.forename: Yihang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Laboratory of Developmental Nutrition, Department of Animal Science, North Carolina State University, Raleigh, NC chad_stahl@ncsu.edu.
authors.forename: Chad H
authors.initials: CH
authors.lastname: Stahl
mesh_terms: D017667:Adipocytes / Q000187:drug effects; D000818:Animals; D000831:Animals, Newborn; D001846:Bone Development / Q000187:drug effects*; D002118:Calcium / Q000172:deficiency*; D002136:Calcium, Dietary / Q000008:administration & dosage / Q000097:blood*; D002454:Cell Differentiation / Q000187:drug effects; D019070:Cell Lineage / Q000187:drug effects*; D003404:Creatinine / Q000652:urine; D004032:Diet; D004305:Dose-Response Relationship, Drug; D050556:Fatty Acid-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects; D015675:Osteocalcin / Q000235:genetics / Q000378:metabolism; D010012:Osteogenesis / Q000187:drug effects; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism; D010281:Parathyroid Hormone / Q000097:blood; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013552:Swine
chemical_list: D002136:Calcium, Dietary; D050556:Fatty Acid-Binding Proteins; D047495:PPAR gamma; D010281:Parathyroid Hormone; D012333:RNA, Messenger; D015675:Osteocalcin; D003404:Creatinine; D002118:Calcium
keywords: calcium; differentiation potential; mesenchymal stem cells; neonate; swine