scholarly journals Pleckstrin homology (PH) domain and leucine rich repeat phosphatase 1 (Phlpp1) suppresses parathyroid hormone receptor 1 (Pth1r) expression and signaling during bone growth

Author(s):  
Samantha R. Weaver ◽  
Earnest L. Taylor ◽  
Elizabeth L. Zars ◽  
Katherine M. Arnold ◽  
Elizabeth W. Bradley ◽  
...  
2020 ◽  
Author(s):  
Samantha R. Weaver ◽  
Earnest L. Taylor ◽  
Elizabeth L. Zars ◽  
Katherine M. Arnold ◽  
Elizabeth W. Bradley ◽  
...  

ABSTRACTEndochondral ossification is tightly controlled by a coordinated network of signaling cascades including parathyroid hormone (PTH). PH domain and leucine rich repeat phosphatase (Phlpp1) affects endochondral ossification by suppressing chondrocyte proliferation in the growth plate, longitudinal bone growth, and bone mineralization. As such, Phlpp1−/− mice have shorter long bones, thicker growth plates, and proportionally larger growth plate proliferative zones. The goal of this study was to determine how Phlpp1 deficiency affects PTH signaling during bone growth. Transcriptomic analysis revealed greater Pth1r expression and H3K27ac enrichment at the Pth1r promoter in Phlpp1-deficient chondrocytes. PTH(1-34) enhanced and PTH(7-34) attenuated cell proliferation, cAMP signaling, CREB phosphorylation, and cell metabolic activity in Phlpp1-inhibited chondrocytes. To understand the role of Pth1r action in the endochondral phenotypes of Phlpp1-deficient mice, Phlpp1−/− mice were injected with Pth1r ligand PTH(7-34) daily for the first four weeks of life. PTH(7-34) reversed the abnormal growth plate and long bone growth phenotypes of Phlpp1−/− mice but did not rescue deficits in bone mineral density or trabecular number. These results demonstrate that elevated Pth1r expression and signaling contributes to increased proliferation in Phlpp1−/− chondrocytes and shorter bones in Phlpp1-deficient mice. Our data reveal a novel molecular relationship between Phlpp1 and Pth1r in chondrocytes during growth plate development and longitudinal bone growth.


2019 ◽  
Author(s):  
Kathryn M. Appleton ◽  
Mi-Hye Lee ◽  
Erik G. Strungs ◽  
Carlos Nogueras-Ortiz ◽  
Diane Gesty-Palmer ◽  
...  

2019 ◽  
Vol 141 (37) ◽  
pp. 14486-14490 ◽  
Author(s):  
Shi Liu ◽  
Frederic G. Jean-Alphonse ◽  
Alex D. White ◽  
Denise Wootten ◽  
Patrick M. Sexton ◽  
...  

2015 ◽  
Vol 29 (2) ◽  
pp. 307-321 ◽  
Author(s):  
Percy H. Carter ◽  
Thomas Dean ◽  
Brijesh Bhayana ◽  
Ashok Khatri ◽  
Raj Rajur ◽  
...  

Abstract The parathyroid hormone receptor-1 (PTHR1) plays critical roles in regulating blood calcium levels and bone metabolism and is thus of interest for small-molecule ligand development. Of the few small-molecule ligands reported for the PTHR1, most are of low affinity, and none has a well-defined mechanism of action. Here, we show that SW106 and AH-3960, compounds previously identified to act as an antagonist and agonist, respectively, on the PTHR1, each bind to PTHR1-delNT, a PTHR1 construct that lacks the large amino-terminal extracellular domain used for binding endogenous PTH peptide ligands, with the same micromolar affinity with which it binds to the intact PTHR1. SW106 antagonized PTHR1-mediated cAMP signaling induced by the peptide analog, M-PTH(1–11), as well as by the native PTH(1–9) sequence, as tethered to the extracellular end of transmembrane domain (TMD) helix-1 of the receptor. SW106, however, did not function as an inverse agonist on either PTHR1-H223R or PTHR1-T410P, which have activating mutations at the cytoplasmic ends of TMD helices 2 and 6, respectively. The overall data indicate that SW106 and AH-3960 each bind to the PTHR1 TMD region and likely to within an extracellularly exposed area that is occupied by the N-terminal residues of PTH peptides. Additionally, they suggest that the inhibitory effects of SW106 are limited to the extracellular portions of the TMD region that mediate interactions with agonist ligands but do not extend to receptor-activation determinants situated more deeply in the helical bundle. The study helps to elucidate potential mechanisms of small-molecule binding at the PTHR1.


The Lancet ◽  
1978 ◽  
Vol 312 (8102) ◽  
pp. 1222-1224 ◽  
Author(s):  
H Jüppner ◽  
A.A Bialasiewicz ◽  
R.D Hesch

Sign in / Sign up

Export Citation Format

Share Document