2023
Multifocal heterotopic ossification in a man with germline variants of LIM Mineralization Protein‐1 (LMP‐1)
Sangadala S, Shore E, Xu M, Bergwitz C, Lozano‐Calderon S, Lin A, Boden S, Kaplan F. Multifocal heterotopic ossification in a man with germline variants of LIM Mineralization Protein‐1 (LMP‐1). American Journal Of Medical Genetics Part A 2023, 191: 2164-2174. PMID: 37218523, DOI: 10.1002/ajmg.a.63304.Peer-Reviewed Original ResearchConceptsLIM mineralization protein-1Bone morphogenetic protein (BMP) pathwayGermline variantsBone morphogenetic proteinRecombinant BMP-2LMP-1Gene-disease relationshipsC2C12 cellsGenetic analysisIntracellular proteinsWT proteinHeterotopic ossificationProtein pathwayOsteoblast markersWT cellsBMP-2Protein 1Coding variantsGene-diseaseProtein levelsControl cellsPathogenic variantsLMP-1 variantsCo-transfectionMC3T3 cells
2021
Phosphorus bioaccessibility measured in four amino acid–based formulas using in-vitro batch digestion translates well into phosphorus bioavailability in mice
Chande S, Dijk F, Fetene J, Yannicelli S, Carpenter TO, van Helvoort A, Bergwitz C. Phosphorus bioaccessibility measured in four amino acid–based formulas using in-vitro batch digestion translates well into phosphorus bioavailability in mice. Nutrition 2021, 89: 111291. PMID: 34111672, PMCID: PMC8588148, DOI: 10.1016/j.nut.2021.111291.Peer-Reviewed Original ResearchConceptsPhosphorus bioavailabilityAmino acid-based formulaProton pump inhibitorsDigestion modelBioavailability analysisPlasma phosphorus levelsLow phosphorus dietDigestion conditionsBioaccessibilityBioavailabilityStomach acidificationDigestive conditionsIntact fibroblast growth factor 23Phosphorus dietFibroblast growth factor 23Stomach pH.Intact parathyroid hormoneAcid-suppressive medicationsDihydroxy vitamin DGrowth factor 23Phosphorus levelsPhosphorus bioaccessibilityAcidificationPhosphorusIntact fibroblast growth factorFGF23 signalling and physiology.
Ho BB, Bergwitz C. FGF23 signalling and physiology. Journal Of Molecular Endocrinology 2021, 66: r23-r32. PMID: 33338030, PMCID: PMC8782161, DOI: 10.1530/jme-20-0178.Peer-Reviewed Reviews, Practice Guidelines, Standards, and Consensus StatementsConceptsO-glycosylation of FGF23FGF23 signalingSubtilisin-like proprotein convertase furinSuppressing phosphate reabsorptionProprotein convertase furinPost-translationallyO-glycosylationIntact FGF23C-terminusGenetic activityPrevent proteolysisParacrine FGFsHigh-affinity binding sitesFibroblast growth factor 23Fruit flyActive intact FGF23Convertase furinChronic kidney diseaseFGF23 fragmentsGrowth factor 23Physiological roleEndocrine FGFsDihydroxyvitamin D synthesisHyperphosphatemic disordersIntestinal phosphate absorption
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
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 miceEndocrine regulation of MFS2 by branchless controls phosphate excretion and stone formation in Drosophila renal tubules
Rose E, Lee D, Xiao E, Zhao W, Wee M, Cohen J, Bergwitz C. Endocrine regulation of MFS2 by branchless controls phosphate excretion and stone formation in Drosophila renal tubules. Scientific Reports 2019, 9: 8798. PMID: 31217461, PMCID: PMC6584732, DOI: 10.1038/s41598-019-45269-x.Peer-Reviewed Original ResearchConceptsDrosophila renal tubulesFly life spanGenetic ablationRNAi-mediated knockdownInorganic phosphate (Pi) homeostasisHigh-Pi mediumPi transportersAdult fliesControl of FGF signalingHigher speciesPi mediumInduces expressionMFS2FGF signalingExcretion of PiPhosphate homeostasisDrosophilaFly longevityEndocrine regulationHormone fibroblast growth factor 23Renal tubulesHormonal controlPi transportFibroblast growth factor 23Genetic overexpression
2018
Role of phosphate sensing in bone and mineral metabolism
Chande S, Bergwitz C. Role of phosphate sensing in bone and mineral metabolism. Nature Reviews Endocrinology 2018, 14: 637-655. PMID: 30218014, PMCID: PMC8607960, DOI: 10.1038/s41574-018-0076-3.Peer-Reviewed Reviews, Practice Guidelines, Standards, and Consensus StatementsConceptsPi transportersSignal transductionPi homeostasisCellular phosphate homeostasisPhosphate homeostasisExpression of Pi transportersPi-sensing mechanismEssential structural componentIntracellular signal transductionPi transportMulticellular organismsInositol pyrophosphatesIntracellular Pi levelsDomain proteinsRegulation of FGF23 expressionPlasma membranePhosphate sensingDisorders of phosphate homeostasisCell metabolismExtracellular matrixCellular levelHomeostasisTransductionGenetic disordersOrganismsHereditary hypophosphatemic rickets with hypercalciuria: pathophysiology, clinical presentation, diagnosis and therapy
Bergwitz C, Miyamoto KI. Hereditary hypophosphatemic rickets with hypercalciuria: pathophysiology, clinical presentation, diagnosis and therapy. Pflügers Archiv - European Journal Of Physiology 2018, 471: 149-163. PMID: 30109410, DOI: 10.1007/s00424-018-2184-2.ChaptersConceptsElevated 1,25(OH)2D levelsHereditary hypophosphatemic ricketsHypophosphatemic ricketsActive vitamin D analoguesEnhanced intestinal calcium absorptionActive vitamin D analogsFibroblast growth factor 23Kidney stonesRare autosomal recessive disorderIntestinal calcium absorptionGrowth factor 23Risk of kidney stonesUrinary phosphate wastingDistal renal tubulesVitamin D analogsX-linked hypophosphatemiaAutosomal recessive disorderDevelopment of kidney stonesLoss-of-function mutationsSecondary hyperparathyroidismClinical presentationFactor 23Parathyroid hormoneBone lossCalcium absorption
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
2013
Genetic Determinants of Phosphate Response in Drosophila
Bergwitz C, Wee MJ, Sinha S, Huang J, DeRobertis C, Mensah LB, Cohen J, Friedman A, Kulkarni M, Hu Y, Vinayagam A, Schnall-Levin M, Berger B, Perkins LA, Mohr SE, Perrimon N. Genetic Determinants of Phosphate Response in Drosophila. PLOS ONE 2013, 8: e56753. PMID: 23520455, PMCID: PMC3592877, DOI: 10.1371/journal.pone.0056753.Peer-Reviewed Original ResearchConceptsLarval developmentGenome-wide RNAi screenDrosophila larval developmentGenetic determinantsImportant cellular processesNovel genetic determinantsAdult life spanLife spanExtracellular phosphate levelsD-rafRNAi-mediated inhibitionRNAi screenDrosophila melanogasterPhosphate responseCellular processesResponse to phosphateAdult fliesCandidate genesLive fliesMAPK activationAvailability of phosphateCellular responsesHigh phosphate mediumMalpighian tubulesReduced life span
2012
Dietary phosphate modifies lifespan in Drosophila
Bergwitz C. Dietary phosphate modifies lifespan in Drosophila. Nephrology Dialysis Transplantation 2012, 27: 3399-3406. PMID: 22942172, DOI: 10.1093/ndt/gfs362.Peer-Reviewed Reviews, Practice Guidelines, Standards, and Consensus StatementsConceptsImportant cellular processesNutrient-sensing pathwaysDrosophila melanogasterCellular processesLifespan extensionLarval developmentPhosphonoformic acidHuman disordersNormal fliesCellular uptakeSpecific pathwaysEffects of dietary phosphateDrosophilaReduced lifespanModel systemReduced cellular uptakeAdult lifespanLittle phosphateAbsorption of phosphatePathwayLifespanDietary phosphateTherapeutic approachesMelanogasterPowerful toolFanconi-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 analysisRoles of Major Facilitator Superfamily Transporters in Phosphate Response in Drosophila
Bergwitz C, Rasmussen MD, DeRobertis C, Wee MJ, Sinha S, Chen HH, Huang J, Perrimon N. Roles of Major Facilitator Superfamily Transporters in Phosphate Response in Drosophila. PLOS ONE 2012, 7: e31730. PMID: 22359624, PMCID: PMC3280997, DOI: 10.1371/journal.pone.0031730.Peer-Reviewed Original ResearchConceptsActivation of MAPKMajor Facilitator Superfamily (MFS) transporterDrosophila larval developmentRNAi-mediated knockdownMajor facilitator superfamily transportersPutative phosphate transportersDrosophila S2R+ cellsFacilitator superfamily transporterSodium-dependent fashionMetazoan speciesMetazoan cellsDrosophila cellsMammalian cellsPhosphate transporterLarval developmentMajor facilitatorPHO84S2R+ cellsFacilitator superfamilySuperfamily transportersMalpighian tubulesXenopus oocyte assayDrosophilaCellular effectsXenopus oocytesFGF23 and Syndromes of Abnormal Renal Phosphate Handling
Bergwitz C, Jüppner H. FGF23 and Syndromes of Abnormal Renal Phosphate Handling. Advances In Experimental Medicine And Biology 2012, 728: 41-64. PMID: 22396161, PMCID: PMC5234086, DOI: 10.1007/978-1-4614-0887-1_3.Peer-Reviewed Reviews, Practice Guidelines, Standards, and Consensus StatementsConceptsLoss-of-function mutationsParathyroid hormoneAutosomal dominant hypophosphatemic ricketsDentin matrix protein 1Ecto-nucleotide pyrophosphatase/phosphodiesterase 1O-glycosylation of FGF23Hypophosphatemic ricketsAbnormal renal phosphate handlingImpaired O-glycosylationFibroblast growth factor 23Hormonal bone-parathyroid-kidney axisGrowth factor 23Serum phosphate levelsRenal phosphate excretionRenal phosphate handlingFamilial hyperphosphatemic tumoral calcinosisSodium-phosphate cotransporters NaPi-IIaHereditary hypophosphatemic ricketsHyperphosphatemic tumoral calcinosisIncreased serum phosphate levelsFunction mutationsPhosphate-regulating geneRare genetic disorderCotransporter NaPi-IIaDominant hypophosphatemic rickets
2011
An integrative approach to ortholog prediction for disease-focused and other functional studies
Hu Y, Flockhart I, Vinayagam A, Bergwitz C, Berger B, Perrimon N, Mohr SE. An integrative approach to ortholog prediction for disease-focused and other functional studies. BMC Bioinformatics 2011, 12: 357. PMID: 21880147, PMCID: PMC3179972, DOI: 10.1186/1471-2105-12-357.Peer-Reviewed Original ResearchConceptsGenome-wide association studiesIdentification of orthologsModel organismsDisease genesFunctions of human disease genesHuman disease-associated genesGenome-wide association study data setsOrthologous gene relationshipsFunction of orthologsHuman disease genesPercent amino acid identityAmino acid identityDisease-associated genesOnline Mendelian InheritancePossible orthologsOrthologous genesOrtholog predictionOrtholog pairsFunctional genomicsGene functionC. elegansOrthology predictionOrthologous pairsGene relationshipsS. cerevisiae
2010
Acute Down-regulation of Sodium-dependent Phosphate Transporter NPT2a Involves Predominantly the cAMP/PKA Pathway as Revealed by Signaling-selective Parathyroid Hormone Analogs
Nagai S, Okazaki M, Segawa H, Bergwitz C, Dean T, Potts JT, Mahon MJ, Gardella TJ, Jüppner H. Acute Down-regulation of Sodium-dependent Phosphate Transporter NPT2a Involves Predominantly the cAMP/PKA Pathway as Revealed by Signaling-selective Parathyroid Hormone Analogs. Journal Of Biological Chemistry 2010, 286: 1618-1626. PMID: 21047792, PMCID: PMC3020770, DOI: 10.1074/jbc.m110.198416.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsCattleChlorocebus aethiopsCOS CellsCyclic AMPCyclic AMP-Dependent Protein KinasesDown-RegulationHumansIn Vitro TechniquesKidney Tubules, ProximalMaleMiceMice, Inbred C57BLOpossumsOsteoblastsParathyroid HormonePhosphorusPseudohypoparathyroidismRatsSignal TransductionSodiumSodium-Phosphate Cotransporter Proteins, Type IIaConceptsAcute down-regulationNpt2a expressionParathyroid hormoneRenal proximal tubule cellsParathyroid hormone (PTH)/PTH-related peptideCAMP/PKALong-acting PTH analogPTH analogsWild-type miceRenal proximal tubulesIntracellular calcium responsesParathyroid hormone analogProximal tubule cellsOpossum kidney cellsM-PTH(1Prolonged cAMP responsesParathyroid hormone analoguesCAMP/PKA signaling pathwayPTH-dependent regulationRenal brush border membraneClonal cell linesInducing IP(3Pseudohypoparathyroid patientsMembrane expressionCalcium response
2009
Defective O-Glycosylation due to a Novel Homozygous S129P Mutation Is Associated with Lack of Fibroblast Growth Factor 23 Secretion and Tumoral Calcinosis
Bergwitz C, Banerjee S, Abu-Zahra H, Kaji H, Miyauchi A, Sugimoto T, Jüppner H. Defective O-Glycosylation due to a Novel Homozygous S129P Mutation Is Associated with Lack of Fibroblast Growth Factor 23 Secretion and Tumoral Calcinosis. The Journal Of Clinical Endocrinology & Metabolism 2009, 94: 4267-4274. PMID: 19837926, PMCID: PMC2775647, DOI: 10.1210/jc.2009-0961.Peer-Reviewed Original ResearchMeSH KeywordsAmino Acid SequenceAmino Acid SubstitutionAnimalsBase SequenceCalcinosisCarrier StateChlorocebus aethiopsCodonCOS CellsDNA PrimersExonsFibroblast Growth Factor-23Fibroblast Growth FactorsGlycosylationHomozygoteHumansHypophosphatemia, FamilialMolecular Sequence DataNeoplasmsPolymorphism, Single NucleotideProlineSerineConceptsExpression vectors encoding wild-typeSerine to prolineHomozygous mutationFraction of lysatesCOS-7 cellsGlycoprotein fractionDefective O-glycosylationMutant hormoneO-glycosylationProtein speciesExon 2Poor secretionCOS-7Western blot analysisGenetic causeCodon 129Hyperphosphatemic tumoral calcinosisMutationsWild-typeFGF23 mutationsAssociated with lackBlot analysisCarriers in vivoFibroblast growth factorLysates