The parathyroid hormone (PTH)/PTH-related protein (PTHrP) receptor (PTHR1) plays vital roles in bone development and in maintaining calcium and phosphate homeostasis. The PTHR1 mediates these roles by binding two distinct polypeptide hormone ligands - PTHrP and PTH. The PTHR1 is of high medical importance as it is associated with diseases such as osteoporosis, hypoparathyroidism and Jansen's metaphyseal chondrodysplasia. This makes the PTHR1 an important target for therapeutic interventions. Developing effective drugs for the PTHR1 is challenging, however, especially by rational design approaches. The few drugs currently available for the PTHR1 are not ideal. For osteoporosis, the two available drugs: recombinant PTH(1-34), forteo, and a synthetic PTHrP(1-34) analog, abaloparatide, improve bone parameters but utility is limited by factors such as the need for daily injection, as the peptides would be destroyed by gut proteases if taken orally, the potential for adverse effects, such as excess bone resorption and hypercalcemia, and a waning of anabolic efficacy over time. A better understanding of the molecular mechanisms by which ligands bind to the PTHR1 and activate signaling is therefore needed to facilitate the design of more effective PTHR1-based therapies, particularly ones that are orally active. The studies proposed here aim to reveal such new aspects of PTHR1 mechanisms, and to thus define how peptides as well as small-molecules bind to this G protein-coupled receptor and induce selective signaling responses in target cells that ultimately lead to improvements in human health. !

Public Health Relevance

The parathyroid hormone receptor, PTHR1, plays a vital role in bone and calcium physiology, and is an important drug target for a number of diseases, including osteoporosis and hypoparathyroidism. Drug development for the PTHR1 is hampered by a lack of knowledge on how the receptor functions at the molecular level. The studies proposed here are designed to shed light on these basic mechanisms and thus advance knowledge of how this key hormone-receptor system functions in normal biology, and how it might be better controlled pharmacologically to treat human disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Program Projects (P01)
Project #
5P01DK011794-52
Application #
10007844
Study Section
Special Emphasis Panel (ZDK1)
Project Start
Project End
Budget Start
2020-07-01
Budget End
2021-06-30
Support Year
52
Fiscal Year
2020
Total Cost
Indirect Cost
Name
Massachusetts General Hospital
Department
Type
DUNS #
073130411
City
Boston
State
MA
Country
United States
Zip Code
02114
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