2020
Slc20a1/Pit1 and Slc20a2/Pit2 are essential for normal skeletal myofiber function and survival
Chande S, Caballero D, Ho BB, Fetene J, Serna J, Pesta D, Nasiri A, Jurczak M, Chavkin NW, Hernando N, Giachelli CM, Wagner CA, Zeiss C, Shulman GI, Bergwitz C. Slc20a1/Pit1 and Slc20a2/Pit2 are essential for normal skeletal myofiber function and survival. Scientific Reports 2020, 10: 3069. PMID: 32080237, PMCID: PMC7033257, DOI: 10.1038/s41598-020-59430-4.Peer-Reviewed Original ResearchConceptsHyp miceMuscle functionSkeletal muscleMyofiber functionNormal body weightSkeletal muscle atrophyGene dose-dependent reductionConditional knockout miceReduced oxygen consumption rateStimulation of AMP kinaseKnockout miceHypophosphatemic disordersMuscle atrophyERK1/2 activationGrip strengthConditional deletionHormonal changesLow bloodBody weightC2C12 myoblastsMiceFurther evaluationBlood phosphateDependent reductionAMP kinase
2017
Intraperitoneal pyrophosphate treatment reduces renal calcifications in Npt2a null mice
Caballero D, Li Y, Fetene J, Ponsetto J, Chen A, Zhu C, Braddock DT, Bergwitz C. Intraperitoneal pyrophosphate treatment reduces renal calcifications in Npt2a null mice. PLOS ONE 2017, 12: e0180098. PMID: 28704395, PMCID: PMC5509111, DOI: 10.1371/journal.pone.0180098.Peer-Reviewed Original ResearchConceptsRenal calcificationCompared to WT miceElevated urinary excretionRenal stone diseaseNucleotide pyrophosphatase phosphodiesterase 1WT miceDietary calciumUrinary excretionIntraperitoneal administrationStone diseaseNull miceMouse mutationMiceCalcificationNephrocalcinosisNpt2aDisordersUnrecognized factorsContribution of genotypePresent studyPhosphodiesterase 1PPINpt2cPatientsNephrolithiasisResponse of Npt2a knockout mice to dietary calcium and phosphorus
Li Y, Caballero D, Ponsetto J, Chen A, Zhu C, Guo J, Demay M, Jüppner H, Bergwitz C. Response of Npt2a knockout mice to dietary calcium and phosphorus. PLOS ONE 2017, 12: e0176232. PMID: 28448530, PMCID: PMC5407772, DOI: 10.1371/journal.pone.0176232.Peer-Reviewed Original ResearchConceptsCompared to WT miceWT miceDietary calciumDietary phosphateCalcium x phosphorus productUrine phosphate levelsUrinary calcium excretionUrine anion gapDevelopment of novel therapiesWild-typeRenal stone diseaseWild-type miceNpt2a-knockout (KO) miceCalcium excretionFGF23 levelsNovel therapiesPreventing nephrolithiasisPlasma phosphateStone diseaseAnion gapAddition of calciumKnockout micePhosphorus productCalcium phosphate depositionHuman carriers
2016
Impaired urinary osteopontin excretion in Npt2a−/− mice
Caballero D, Li Y, Ponsetto J, Zhu C, Bergwitz C. Impaired urinary osteopontin excretion in Npt2a−/− mice. American Journal Of Physiology. Renal Physiology 2016, 312: f77-f83. PMID: 27784695, PMCID: PMC5283892, DOI: 10.1152/ajprenal.00367.2016.Peer-Reviewed Original ResearchConceptsOPN gene expressionUrinary excretionRenal phosphate wasting disordersHigh-phosphate dietPhosphate wasting disordersOral phosphate supplementationRenal gene expressionRenal stone diseaseGene expressionAdditional risk factorsOPN levelsRole of OPNWasting disordersStone diseaseUrine excretionMouse modelNpt2aRisk factorsMouse mutationPhosphate supplementationRenal phosphateMiceRestored to wild-type levelsExcretionNephrocalcinosisHypophosphatemia promotes lower rates of muscle ATP synthesis
Pesta DH, Tsirigotis DN, Befroy DE, Caballero D, Jurczak MJ, Rahimi Y, Cline GW, Dufour S, Birkenfeld AL, Rothman DL, Carpenter TO, Insogna K, Petersen KF, Bergwitz C, Shulman GI. Hypophosphatemia promotes lower rates of muscle ATP synthesis. The FASEB Journal 2016, 30: 3378-3387. PMID: 27338702, PMCID: PMC5024687, DOI: 10.1096/fj.201600473r.Peer-Reviewed Original ResearchConceptsMuscle ATP synthesisATP synthesisMuscle weaknessIsolated muscle mitochondriaSolute carrier familyWild-type littermate controlsSolute carrier family 34Carrier familyLower ratesInsulin-stimulated ratesMuscle mitochondriaChronic hypophosphatemiaHeart failureHypophosphatemic groupHypophosphatemic miceHypophosphatemiaLittermate controlsKnockout miceBlood PLow ratePlasma PPatientsSimilar findingsMember 1Plasma inorganic phosphate
2008
Genetic Evidence of Serum Phosphate-Independent Functions of FGF-23 on Bone
Sitara D, Kim S, Razzaque MS, Bergwitz C, Taguchi T, Schüler C, Erben RG, Lanske B. Genetic Evidence of Serum Phosphate-Independent Functions of FGF-23 on Bone. PLOS Genetics 2008, 4: e1000154. PMID: 18688277, PMCID: PMC2483943, DOI: 10.1371/journal.pgen.1000154.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsBone and BonesBone DensityCalcification, PhysiologicCells, CulturedFibroblast Growth Factor-23Fibroblast Growth FactorsGene ExpressionHypophosphatemiaMiceMice, Inbred C57BLMice, KnockoutMuscle, SkeletalOsteoblastsPhenotypePhosphatesSerumSkullSodium-Phosphate Cotransporter Proteins, Type IIaUrineConceptsFGF-23 geneFgf-23-/- micePhosphate homeostasisGenetic evidenceFgf-23-/-Regulation of phosphate homeostasisCrucial biological importanceFirst genetic evidenceSystemic phosphate homeostasisSkeletal mineralizationCellular functionsDouble mutantNew mouse lineMaster regulatorProtein abundanceGenomic ablationMolecular mechanismsDouble mutant miceChondrocyte differentiationTargeted disruptionSkeletal phenotypeBiological importanceGenesEnergy metabolismHomeostasis