2020
Different elemental infant formulas show equivalent phosphorus and calcium bioavailability in healthy volunteers
Bergwitz C, Eussen SRBM, Janssens PLHR, Visser M, Carpenter TO, van Helvoort A. Different elemental infant formulas show equivalent phosphorus and calcium bioavailability in healthy volunteers. Nutrition Research 2020, 85: 71-83. PMID: 33450668, DOI: 10.1016/j.nutres.2020.11.004.Peer-Reviewed Original ResearchConceptsGeometric mean ratiosAcid-suppressive medicationsArea under the curveHealthy volunteersSerum phosphateCalcium bioavailabilityGastric acid-suppressive medicationsRetrospective chart reviewSerum calcium concentrationBioavailability of phosphorusCross-over studyInfant formulaElemental formula useSingle oral doseCalcium excretionDouble-blindGram of phosphorusSingle-centerChart reviewOral doseOvernight fastingSerum phosphorusBioequivalence criteriaWashout periodMean ratios
2019
Transgenic mouse model for conditional expression of influenza hemagglutinin-tagged human SLC20A1/PIT1
Chande S, Ho B, Fetene J, Bergwitz C. Transgenic mouse model for conditional expression of influenza hemagglutinin-tagged human SLC20A1/PIT1. PLOS ONE 2019, 14: e0223052. PMID: 31613887, PMCID: PMC6793878, DOI: 10.1371/journal.pone.0223052.Peer-Reviewed Original ResearchMeSH KeywordsActinsAnimalsBeta-GlobinsBiological TransportBone DensityCalcitriolChickensCytomegalovirusFemaleFibroblast Growth Factor-23Fibroblast Growth FactorsFounder EffectHemagglutinin Glycoproteins, Influenza VirusHumansMaleMiceMice, TransgenicOsteoblastsParathyroid HormonePhosphatesPrimary Cell CulturePromoter Regions, GeneticRabbitsRecombinant Fusion ProteinsSkullTranscription Factor Pit-1TransgenesConceptsPrimary calvaria osteoblastsLoxP-stop-loxPLoxP-STOP-loxP cassetteMouse modelDihydroxy vitamin D levelsHemagglutinin (HABone mineral densityVitamin D levelsInfluenza hemagglutinin (HAConditional mouse modelActivation of transgene expressionElevated plasma PiTransgenic mouse modelPlasma iPTHUrine PiBeta-globin geneSerum calciumWT littermatesMineral densityDays of ageProtein excretionD levelsSemi-quantitative RT-PCRStandard chowTransgenic mice
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 levelsExcretionNephrocalcinosis
2014
Mutations in SLC34A3/NPT2c Are Associated with Kidney Stones and Nephrocalcinosis
Dasgupta D, Wee MJ, Reyes M, Li Y, Simm PJ, Sharma A, Schlingmann KP, Janner M, Biggin A, Lazier J, Gessner M, Chrysis D, Tuchman S, Baluarte HJ, Levine MA, Tiosano D, Insogna K, Hanley DA, Carpenter TO, Ichikawa S, Hoppe B, Konrad M, Sävendahl L, Munns CF, Lee H, Jüppner H, Bergwitz C. Mutations in SLC34A3/NPT2c Are Associated with Kidney Stones and Nephrocalcinosis. Journal Of The American Society Of Nephrology 2014, 25: 2366-2375. PMID: 24700880, PMCID: PMC4178443, DOI: 10.1681/asn.2013101085.Peer-Reviewed Original ResearchConceptsIdiopathic hypercalciuriaDecreased tubular reabsorption of phosphateIncreased risk of kidney stone formationSerum 1,25(OH)2 vitamin DTubular reabsorption of phosphateAssociated with kidney stonesVitamin D levelsSolute carrier family 34Renal phosphate wastingDecreased serum phosphateHereditary hypophosphatemic ricketsHealthy family membersReabsorption of phosphateRisk of kidney stone formationRickets/osteomalaciaDecreased tubular reabsorptionKidney stone formationSLC34A3 mutationsIndependent of genotypeMedullary nephrocalcinosisSerum phosphateVitamin DDependent phosphate cotransporterTubular reabsorptionD levels
2012
Fanconi-Bickel Syndrome and Autosomal Recessive Proximal Tubulopathy with Hypercalciuria (ARPTH) Are Allelic Variants Caused by GLUT2 Mutations
Mannstadt M, Magen D, Segawa H, Stanley T, Sharma A, Sasaki S, Bergwitz C, Mounien L, Boepple P, Thorens B, Zelikovic I, Jüppner H. Fanconi-Bickel Syndrome and Autosomal Recessive Proximal Tubulopathy with Hypercalciuria (ARPTH) Are Allelic Variants Caused by GLUT2 Mutations. The Journal Of Clinical Endocrinology & Metabolism 2012, 97: e1978-e1986. PMID: 22865906, PMCID: PMC3462928, DOI: 10.1210/jc.2012-1279.Peer-Reviewed Original ResearchMeSH KeywordsAdolescentAmino Acid SequenceAnimalsFamilial Hypophosphatemic RicketsFamily HealthFanconi SyndromeFemaleGenes, RecessiveGenetic VariationGenome-Wide Association StudyGlucose Transporter Type 1Glucose Transporter Type 2HumansHypercalciuriaHypophosphatemia, FamilialKidney Tubules, ProximalMaleMiceMice, TransgenicMolecular Sequence DataOocytesPedigreeRicketsSodium-Phosphate Cotransporter Proteins, Type IIaSodium-Phosphate Cotransporter Proteins, Type IIcXenopus laevisConceptsGlucose transporter 2Sequence analysis of candidate genesCandidate genesSequence analysisGenome-wide linkage scanAnalysis of candidate genesFanconi-Bickel syndromeProximal renal tubulopathyRenal tubulopathyNucleotide sequence analysisGenetic mappingHomozygous mutationPhosphate importLinkage scanMolecular basisXenopus oocytesTransport of glucoseGLUT2 mutationsMolecular levelGenesGlucose transportUrinary phosphate excretionAllelic variantsPhosphate homeostasisDirect nucleotide sequence analysisNovel NaPi-IIc mutations causing HHRH and idiopathic hypercalciuria in several unrelated families: Long-term follow-up in one kindred
Yu Y, Sanderson SR, Reyes M, Sharma A, Dunbar N, Srivastava T, Jüppner H, Bergwitz C. Novel NaPi-IIc mutations causing HHRH and idiopathic hypercalciuria in several unrelated families: Long-term follow-up in one kindred. Bone 2012, 50: 1100-1106. PMID: 22387237, PMCID: PMC3322249, DOI: 10.1016/j.bone.2012.02.015.Peer-Reviewed Original ResearchConceptsVitamin D levelsIdiopathic hypercalciuriaKindred APTH levelsD levelsLong-term follow-upBilateral medullary nephrocalcinosisMild bone abnormalitiesSuppressed PTH levelsMutation c.Hereditary hypophosphatemic ricketsRenal phosphate-wastingRickets/osteomalaciaAssess treatment efficacyCompound heterozygous mutationsHHRH patientsKindred BKindred CSLC34A3 mutationsOral phosphateHeterozygous c.Medullary nephrocalcinosisHeterozygous mutationsNaPi-IIcHypercalciuria
2011
Hereditary hypophosphatemic rickets with hypercalciuria and nephrolithiasis—Identification of a novel SLC34A3/NaPi‐IIc mutation
Phulwani P, Bergwitz C, Jaureguiberry G, Rasoulpour M, Estrada E. Hereditary hypophosphatemic rickets with hypercalciuria and nephrolithiasis—Identification of a novel SLC34A3/NaPi‐IIc mutation. American Journal Of Medical Genetics Part A 2011, 155: 626-633. PMID: 21344632, PMCID: PMC4777326, DOI: 10.1002/ajmg.a.33832.Peer-Reviewed Original ResearchMeSH KeywordsBase SequenceChild, PreschoolFamilial Hypophosphatemic RicketsFemaleHumansHypercalciuriaInfantInfant, NewbornMaleMolecular Sequence DataMutationNephrolithiasisPedigreePolymorphism, Single NucleotidePregnancyRestriction MappingReverse Transcriptase Polymerase Chain ReactionRNA, MessengerSodium-Phosphate Cotransporter Proteins, Type IIcConceptsHereditary hypophosphatemic ricketsHypophosphatemic ricketsElevated 1,25-dihydroxyvitamin DGastrointestinal calcium absorptionHistory of nephrolithiasisIncreased gastrointestinal calcium absorptionPTH levelsRecurrent nephrolithiasisRenal ultrasoundSerum calciumCalcium absorptionNaPi-IIcPatient's motherHypercalciuriaSplicing mutationCompound heterozygosityNephrolithiasisRicketsNovel splice mutationHHRHDihydroxyvitaminPhenotypic changesMutationsMothersSplice mutation
2010
Autoimmune Hypocalciuric Hypercalcemia Unresponsive to Glucocorticoid Therapy in a Patient with Blocking Autoantibodies against the Calcium-Sensing Receptor
Pallais JC, Kemp EH, Bergwitz C, Kantham L, Slovik DM, Weetman AP, Brown EM. Autoimmune Hypocalciuric Hypercalcemia Unresponsive to Glucocorticoid Therapy in a Patient with Blocking Autoantibodies against the Calcium-Sensing Receptor. The Journal Of Clinical Endocrinology & Metabolism 2010, 96: 672-680. PMID: 21159843, PMCID: PMC3047232, DOI: 10.1210/jc.2010-1739.Peer-Reviewed Original ResearchMeSH KeywordsAgedAntibodies, AntinuclearAntibodies, BlockingAutoantibodiesAutoimmune DiseasesCalciumDrug ResistanceExtracellular Signal-Regulated MAP KinasesFemaleGlucocorticoidsHumansHypercalcemiaImmunoglobulin EImmunoprecipitationInositol PhosphatesParathyroid HormonePhosphorylationReceptors, Calcium-SensingStimulation, ChemicalType C PhospholipasesConceptsAutoimmune hypocalciuric hypercalcemiaUrinary calcium excretionCalcium-sensing receptorGlucocorticoid therapyGlucocorticoid treatmentPTH levelsCalcium excretionAutoantibody titersAccumulation of inositol-1-phosphateTrial of glucocorticoid therapyHypocalciuric hypercalcemiaEffect of extracellular Ca(2Regulation of PTH secretionSerum PTH levelsElevated PTH levelsInositol-1-phosphate accumulationPTH-mediated hypercalcemiaIonized calcium concentrationAntibody-mediated inhibitionExtracellular Ca(2PTH secretionBlocking autoantibodiesAutoimmune disordersSerum totalHypercalcemia
2008
A novel missense mutation in SLC34A3 that causes hereditary hypophosphatemic rickets with hypercalciuria in humans identifies threonine 137 as an important determinant of sodium-phosphate cotransport in NaPi-IIc
Jaureguiberry G, Carpenter TO, Forman S, Jüppner H, Bergwitz C. A novel missense mutation in SLC34A3 that causes hereditary hypophosphatemic rickets with hypercalciuria in humans identifies threonine 137 as an important determinant of sodium-phosphate cotransport in NaPi-IIc. American Journal Of Physiology. Renal Physiology 2008, 295: f371-f379. PMID: 18480181, PMCID: PMC2519180, DOI: 10.1152/ajprenal.00090.2008.Peer-Reviewed Original ResearchMeSH KeywordsAdultAllelesAnimalsBase SequenceExocytosisFamilial Hypophosphatemic RicketsFemaleHaplotypesHumansHypercalciuriaKidneyMaleMolecular Sequence DataMutation, MissenseOocytesOpossumsPhosphatesPolymorphism, Single NucleotideSodiumSodium-Phosphate Cotransporter ProteinsSodium-Phosphate Cotransporter Proteins, Type IIcThreonineXenopus laevisConceptsEncoding enhanced green fluorescent proteinHereditary hypophosphatemic ricketsNaPi-IIcSodium-phosphate cotransporterLoss of expressionAmino acid residuesSodium-phosphate cotransportGreen fluorescence proteinImportant functional roleComplete lossOpossum kidneyHypophosphatemic ricketsXenopus laevis oocytesNovel missense mutationPaternal alleleWild-typeFunctional analysisFluorescence proteinNH2 terminusAcid residuesApical patchesCompound heterozygous mutationsExpression plasmidFunctional roleRecurrent kidney stones
2005
SLC34A3 Mutations in Patients with Hereditary Hypophosphatemic Rickets with Hypercalciuria Predict a Key Role for the Sodium-Phosphate Cotransporter NaPi-IIc in Maintaining Phosphate Homeostasis
Bergwitz C, Roslin NM, Tieder M, Loredo-Osti JC, Bastepe M, Abu-Zahra H, Frappier D, Burkett K, Carpenter TO, Anderson D, Garabédian M, Sermet I, Fujiwara TM, Morgan K, Tenenhouse HS, Jüppner H. SLC34A3 Mutations in Patients with Hereditary Hypophosphatemic Rickets with Hypercalciuria Predict a Key Role for the Sodium-Phosphate Cotransporter NaPi-IIc in Maintaining Phosphate Homeostasis. American Journal Of Human Genetics 2005, 78: 179-192. PMID: 16358214, PMCID: PMC1380228, DOI: 10.1086/499409.Peer-Reviewed Original ResearchConceptsConsanguineous BedouinFirst membrane-spanning domainMembrane-spanning domainsPhosphate homeostasisRenal sodium-phosphate cotransporterNucleotide sequence analysisDihydroxyvitamin D levelsSingle nucleotide deletionHereditary hypophosphatemic ricketsCompound heterozygous missenseSLC34A3 mutationsHomozygous single nucleotide deletionHypophosphatemic ricketsLinkage scanCandidate genesGenomic DNASodium-phosphate cotransporterSequence analysisD levelsHomozygosity mappingDeletion mutationsGenomewide linkage scanKey roleChromosome 9q34Mutations
2001
Identification of novel CBFA1/RUNX2 mutations causing cleidocranial dysplasia
Bergwitz C, Prochnau A, Mayr B, Kramer F, Rittierodt M, Berten H, Hausamen J, Brabant G. Identification of novel CBFA1/RUNX2 mutations causing cleidocranial dysplasia. Journal Of Inherited Metabolic Disease 2001, 24: 648-656. PMID: 11768584, DOI: 10.1023/a:1012758925617.Peer-Reviewed Original ResearchConceptsCleidocranial dysplasiaPatient's leukocyte DNADelayed tooth eruptionBsmI restriction siteHealthy family membersRUNX2 mutationAberrant amino acidsClavicular dysplasiaPatent fontanelsCore-binding factor a1Haplotype insufficiencyTooth budsTooth eruptionShort statureBone densityLeukocyte DNAIncreased riskGrowth retardationRestriction sitesDistal phalanxNucleotide changesDysplasiaPremature stopFrameshift mutationHealthy members
1997
Cloning and characterization of the vitamin D receptor from Xenopus laevis.
Li Y, Bergwitz C, Jüppner H, Demay M. Cloning and characterization of the vitamin D receptor from Xenopus laevis. Endocrinology 1997, 138: 2347-53. PMID: 9165021, DOI: 10.1210/endo.138.6.5210.Peer-Reviewed Original ResearchMeSH KeywordsAgingAmino Acid SequenceAnimalsBase SequenceBone and BonesChickensCloning, MolecularDimerizationEmbryo, NonmammalianFemaleGene Expression Regulation, DevelopmentalHumansIntestine, SmallKidneyMiceMolecular Sequence DataOrgan SpecificityPolymerase Chain ReactionRatsReceptors, CalcitriolReceptors, Retinoic AcidRecombinant ProteinsRetinoic Acid Receptor alphaSequence Homology, Amino AcidSkinSpecies SpecificityXenopus laevisConceptsVitamin D response elementRat osteocalcin vitamin D response elementVitamin D receptorOsteocalcin vitamin D response elementLower vertebrate speciesMessenger RNA speciesHuman vitamin D receptorMouse retinoid X receptor alphaAmino acid residuesRetinoid X receptor alphaRat osteocalcin vitamin D responsive elementAmino acid levelsX receptor alphaVertebrate speciesRNA speciesMammalian cellsTransfected mammalian cellsXenopus developmentDependent transactivationD response elementNuclear receptor superfamilyXenopus tissuesDNA bindingIon homeostasisNorthern analysis
1995
Pseudohypoparathyroidism type Ib is not caused by mutations in the coding exons of the human parathyroid hormone (PTH)/PTH-related peptide receptor gene
Schipani E, Weinstein LS, Bergwitz C, Iida-Klein A, Kong XF, Stuhrmann M, Kruse K, Whyte MP, Murray T, Schmidtke J. Pseudohypoparathyroidism type Ib is not caused by mutations in the coding exons of the human parathyroid hormone (PTH)/PTH-related peptide receptor gene. The Journal Of Clinical Endocrinology & Metabolism 1995, 80: 1611-1621. PMID: 7745008, DOI: 10.1210/jcem.80.5.7745008.Peer-Reviewed Original ResearchConceptsPseudohypoparathyroidism type IbPHP-IbCoding exonsExon GNucleotide sequenceBase changesHuman genomic DNA clonesExon E2Receptor geneTemperature gradient gel electrophoresisGenomic DNA clonesRestriction enzyme mappingReceptor cytoplasmic tailPHP-Ib patientsPTH/PTH-related peptideReverse transcriptase-polymerase chain reactionSplice donor sitePTH/PTHrP receptor geneTranscriptase-polymerase chain reactionGradient gel electrophoresisType IbChain reactionDirect nucleotide sequencingWild-type receptorNorthern blot analysis