Cinacalcet corrects hypercalcemia in mice with an inactivating Gα11 mutation

Sarah A. Howles, Fadil M. Hannan, Caroline M. Gorvin, Sian E. Piret, Anju Paudyal, Michelle Stewart, Tertius A. Hough, M. Andrew Nesbit, Sara Wells, Stephen D.M. Brown, Roger D. Cox, Rajesh V. Thakker

Research output: Contribution to journalArticle

Abstract

Loss-of-function mutations of GNA11, which encodes G-protein subunit α11 (Gα11), a signaling partner for the calcium-sensing receptor (CaSR), result in familial hypocalciuric hypercalcemia type 2 (FHH2). FHH2 is characterized by hypercalcemia, inappropriately normal or raised parathyroid hormone (PTH) concentrations, and normal or low urinary calcium excretion. A mouse model for FHH2 that would facilitate investigations of the in vivo role of Gα11 and the evaluation of calcimimetic drugs, which are CaSR allosteric activators, is not available. We therefore screened DNA from > 10,000 mice treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU) for GNA11 mutations and identified a Gα11 variant, Asp195Gly (D195G), which downregulated CaSR-mediated intracellular calcium signaling in vitro, consistent with it being a loss-of-function mutation. Treatment with the calcimimetic cinacalcet rectified these signaling responses. In vivo studies showed mutant heterozygous (Gna11+/195G) and homozygous (Gna11195G/195G) mice to be hypercalcemic with normal or increased plasma PTH concentrations and normal urinary calcium excretion. Cinacalcet (30mg/kg orally) significantly reduced plasma albumin–adjusted calcium and PTH concentrations in Gna11+/195G and Gna11195G/195G mice. Thus, our studies have established a mouse model with a germline loss-of-function Gα11 mutation that is representative for FHH2 in humans and demonstrated that cinacalcet can correct the associated abnormalities of plasma calcium and PTH.
LanguageEnglish
JournalJCI Insight
Volume2
Issue number20
DOIs
Publication statusPublished - 19 Oct 2017

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Protein Subunits
Hypercalcemia
GTP-Binding Proteins
Parathyroid Hormone
Calcium-Sensing Receptors
Mutation
Calcium
Ethylnitrosourea
Drug Evaluation
Calcium Signaling
Mutagens
Serum Albumin
Down-Regulation
Cinacalcet Hydrochloride
Hypocalciuric hypercalcemia, familial, type 2
DNA

Keywords

  • hypercalcemia
  • G protein
  • calcimimetic
  • mutation

Cite this

Howles, S. A., Hannan, F. M., Gorvin, C. M., Piret, S. E., Paudyal, A., Stewart, M., ... Thakker, R. V. (2017). Cinacalcet corrects hypercalcemia in mice with an inactivating Gα11 mutation. 2(20). https://doi.org/10.1172/jci.insight.96540
Howles, Sarah A. ; Hannan, Fadil M. ; Gorvin, Caroline M. ; Piret, Sian E. ; Paudyal, Anju ; Stewart, Michelle ; Hough, Tertius A. ; Nesbit, M. Andrew ; Wells, Sara ; Brown, Stephen D.M. ; Cox, Roger D. ; Thakker, Rajesh V. / Cinacalcet corrects hypercalcemia in mice with an inactivating Gα11 mutation. 2017 ; Vol. 2, No. 20.
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abstract = "Loss-of-function mutations of GNA11, which encodes G-protein subunit α11 (Gα11), a signaling partner for the calcium-sensing receptor (CaSR), result in familial hypocalciuric hypercalcemia type 2 (FHH2). FHH2 is characterized by hypercalcemia, inappropriately normal or raised parathyroid hormone (PTH) concentrations, and normal or low urinary calcium excretion. A mouse model for FHH2 that would facilitate investigations of the in vivo role of Gα11 and the evaluation of calcimimetic drugs, which are CaSR allosteric activators, is not available. We therefore screened DNA from > 10,000 mice treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU) for GNA11 mutations and identified a Gα11 variant, Asp195Gly (D195G), which downregulated CaSR-mediated intracellular calcium signaling in vitro, consistent with it being a loss-of-function mutation. Treatment with the calcimimetic cinacalcet rectified these signaling responses. In vivo studies showed mutant heterozygous (Gna11+/195G) and homozygous (Gna11195G/195G) mice to be hypercalcemic with normal or increased plasma PTH concentrations and normal urinary calcium excretion. Cinacalcet (30mg/kg orally) significantly reduced plasma albumin–adjusted calcium and PTH concentrations in Gna11+/195G and Gna11195G/195G mice. Thus, our studies have established a mouse model with a germline loss-of-function Gα11 mutation that is representative for FHH2 in humans and demonstrated that cinacalcet can correct the associated abnormalities of plasma calcium and PTH.",
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Howles, SA, Hannan, FM, Gorvin, CM, Piret, SE, Paudyal, A, Stewart, M, Hough, TA, Nesbit, MA, Wells, S, Brown, SDM, Cox, RD & Thakker, RV 2017, 'Cinacalcet corrects hypercalcemia in mice with an inactivating Gα11 mutation', vol. 2, no. 20. https://doi.org/10.1172/jci.insight.96540

Cinacalcet corrects hypercalcemia in mice with an inactivating Gα11 mutation. / Howles, Sarah A.; Hannan, Fadil M.; Gorvin, Caroline M.; Piret, Sian E.; Paudyal, Anju; Stewart, Michelle; Hough, Tertius A.; Nesbit, M. Andrew; Wells, Sara; Brown, Stephen D.M.; Cox, Roger D.; Thakker, Rajesh V.

Vol. 2, No. 20, 19.10.2017.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Cinacalcet corrects hypercalcemia in mice with an inactivating Gα11 mutation

AU - Howles, Sarah A.

AU - Hannan, Fadil M.

AU - Gorvin, Caroline M.

AU - Piret, Sian E.

AU - Paudyal, Anju

AU - Stewart, Michelle

AU - Hough, Tertius A.

AU - Nesbit, M. Andrew

AU - Wells, Sara

AU - Brown, Stephen D.M.

AU - Cox, Roger D.

AU - Thakker, Rajesh V.

PY - 2017/10/19

Y1 - 2017/10/19

N2 - Loss-of-function mutations of GNA11, which encodes G-protein subunit α11 (Gα11), a signaling partner for the calcium-sensing receptor (CaSR), result in familial hypocalciuric hypercalcemia type 2 (FHH2). FHH2 is characterized by hypercalcemia, inappropriately normal or raised parathyroid hormone (PTH) concentrations, and normal or low urinary calcium excretion. A mouse model for FHH2 that would facilitate investigations of the in vivo role of Gα11 and the evaluation of calcimimetic drugs, which are CaSR allosteric activators, is not available. We therefore screened DNA from > 10,000 mice treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU) for GNA11 mutations and identified a Gα11 variant, Asp195Gly (D195G), which downregulated CaSR-mediated intracellular calcium signaling in vitro, consistent with it being a loss-of-function mutation. Treatment with the calcimimetic cinacalcet rectified these signaling responses. In vivo studies showed mutant heterozygous (Gna11+/195G) and homozygous (Gna11195G/195G) mice to be hypercalcemic with normal or increased plasma PTH concentrations and normal urinary calcium excretion. Cinacalcet (30mg/kg orally) significantly reduced plasma albumin–adjusted calcium and PTH concentrations in Gna11+/195G and Gna11195G/195G mice. Thus, our studies have established a mouse model with a germline loss-of-function Gα11 mutation that is representative for FHH2 in humans and demonstrated that cinacalcet can correct the associated abnormalities of plasma calcium and PTH.

AB - Loss-of-function mutations of GNA11, which encodes G-protein subunit α11 (Gα11), a signaling partner for the calcium-sensing receptor (CaSR), result in familial hypocalciuric hypercalcemia type 2 (FHH2). FHH2 is characterized by hypercalcemia, inappropriately normal or raised parathyroid hormone (PTH) concentrations, and normal or low urinary calcium excretion. A mouse model for FHH2 that would facilitate investigations of the in vivo role of Gα11 and the evaluation of calcimimetic drugs, which are CaSR allosteric activators, is not available. We therefore screened DNA from > 10,000 mice treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU) for GNA11 mutations and identified a Gα11 variant, Asp195Gly (D195G), which downregulated CaSR-mediated intracellular calcium signaling in vitro, consistent with it being a loss-of-function mutation. Treatment with the calcimimetic cinacalcet rectified these signaling responses. In vivo studies showed mutant heterozygous (Gna11+/195G) and homozygous (Gna11195G/195G) mice to be hypercalcemic with normal or increased plasma PTH concentrations and normal urinary calcium excretion. Cinacalcet (30mg/kg orally) significantly reduced plasma albumin–adjusted calcium and PTH concentrations in Gna11+/195G and Gna11195G/195G mice. Thus, our studies have established a mouse model with a germline loss-of-function Gα11 mutation that is representative for FHH2 in humans and demonstrated that cinacalcet can correct the associated abnormalities of plasma calcium and PTH.

KW - hypercalcemia

KW - G protein

KW - calcimimetic

KW - mutation

U2 - 10.1172/jci.insight.96540

DO - 10.1172/jci.insight.96540

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Howles SA, Hannan FM, Gorvin CM, Piret SE, Paudyal A, Stewart M et al. Cinacalcet corrects hypercalcemia in mice with an inactivating Gα11 mutation. 2017 Oct 19;2(20). https://doi.org/10.1172/jci.insight.96540