Interrelated role of Klotho and calcium-sensing receptor in parathyroid hormone synthesis and parathyroid hyperplasia

Proc Natl Acad Sci U S A. 2018 Apr 17;115(16):E3749-E3758. doi: 10.1073/pnas.1717754115. Epub 2018 Apr 4.


The pathogenesis of parathyroid gland hyperplasia is poorly understood, and a better understanding is essential if there is to be improvement over the current strategies for prevention and treatment of secondary hyperparathyroidism. Here we investigate the specific role of Klotho expressed in the parathyroid glands (PTGs) in mediating parathyroid hormone (PTH) and serum calcium homeostasis, as well as the potential interaction between calcium-sensing receptor (CaSR) and Klotho. We generated mouse strains with PTG-specific deletion of Klotho and CaSR and dual deletion of both genes. We show that ablating CaSR in the PTGs increases PTH synthesis, that Klotho has a pivotal role in suppressing PTH in the absence of CaSR, and that CaSR together with Klotho regulates PTH biosynthesis and PTG growth. We utilized the tdTomato gene in our mice to visualize and collect PTGs to reveal an inhibitory function of Klotho on PTG cell proliferation. Chronic hypocalcemia and ex vivo PTG culture demonstrated an independent role for Klotho in mediating PTH secretion. Moreover, we identify an interaction between PTG-expressed CaSR and Klotho. These findings reveal essential and interrelated functions for CaSR and Klotho during parathyroid hyperplasia.

Keywords: FGF23; chronic kidney disease; conditional knockout; secondary hyperparathyroidism; tdTomato.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone and Bones / pathology
  • Calcium / metabolism
  • Calcium, Dietary / administration & dosage
  • Female
  • Fibroblast Growth Factor-23
  • Glucuronidase / deficiency
  • Glucuronidase / genetics
  • Glucuronidase / physiology*
  • Homeostasis
  • Hypercalcemia / genetics
  • Hypercalcemia / pathology
  • Hyperparathyroidism / genetics
  • Hyperparathyroidism / pathology
  • Hyperplasia
  • Hypocalcemia / metabolism
  • Hypophosphatemia / genetics
  • Hypophosphatemia / pathology
  • Immunoprecipitation
  • Kidney / pathology
  • Klotho Proteins
  • Male
  • Mice
  • Parathyroid Glands / metabolism*
  • Parathyroid Glands / pathology
  • Parathyroid Hormone / biosynthesis*
  • Parathyroid Hormone / genetics
  • Protein Interaction Mapping
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • Receptors, Calcium-Sensing
  • Receptors, G-Protein-Coupled / deficiency
  • Receptors, G-Protein-Coupled / genetics
  • Receptors, G-Protein-Coupled / physiology*


  • CASR protein, mouse
  • Calcium, Dietary
  • Fgf23 protein, mouse
  • Parathyroid Hormone
  • RNA, Messenger
  • Receptors, Calcium-Sensing
  • Receptors, G-Protein-Coupled
  • Fibroblast Growth Factor-23
  • Glucuronidase
  • Klotho Proteins
  • Calcium