Ciliary parathyroid hormone signaling activates transforming growth factor-β to maintain intervertebral disc homeostasis during aging

Liwei Zheng, Yong Cao, Shuangfei Ni, Huabin Qi, Zemin Ling, Xin Xu, Xuenong Zou, Tianding Wu, Ruoxian Deng, Bo Hu, Bo Gao, Hao Chen, Yusheng Li, Jianxi Zhu, Francis Tintani, Shadpour Demehri, Amit Jain, Khaled M. Kebaish, Shenghui Liao, Cheryle A. SéguinJanet L. Crane, Mei Wan, Hongbin Lu, Paul D. Sponseller, Lee H. Riley, Xuedong Zhou, Jianzhong Hu, Xu Cao

Research output: Contribution to journalArticle

Abstract

Degenerative disc disease (DDD) is associated with intervertebral disc degeneration of spinal instability. Here, we report that the cilia of nucleus pulposus (NP) cells mediate mechanotransduction to maintain anabolic activity in the discs. We found that mechanical stress promotes transport of parathyroid hormone 1 receptor (PTH1R) to the cilia and enhances parathyroid hormone (PTH) signaling in NP cells. PTH induces transcription of integrin αvβ6 to activate the transforming growth factor (TGF)-β-connective tissue growth factor (CCN2)-matrix proteins signaling cascade. Intermittent injection of PTH (iPTH) effectively attenuates disc degeneration of aged mice by direct signaling through NP cells, specifically improving intervertebral disc height and volume by increasing levels of TGF-β activity, CCN2, and aggrecan. PTH1R is expressed in both mouse and human NP cells. Importantly, knockout PTH1R or cilia in the NP cells results in significant disc degeneration and blunts the effect of PTH on attenuation of aged discs. Thus, mechanical stress-induced transport of PTH1R to the cilia enhances PTH signaling, which helps maintain intervertebral disc homeostasis, particularly during aging, indicating therapeutic potential of iPTH for DDD.

Original languageEnglish (US)
Article number21
JournalBone Research
Volume6
Issue number1
DOIs
StatePublished - Dec 1 2018

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ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Physiology
  • Histology

Cite this

Zheng, L., Cao, Y., Ni, S., Qi, H., Ling, Z., Xu, X., Zou, X., Wu, T., Deng, R., Hu, B., Gao, B., Chen, H., Li, Y., Zhu, J., Tintani, F., Demehri, S., Jain, A., Kebaish, K. M., Liao, S., ... Cao, X. (2018). Ciliary parathyroid hormone signaling activates transforming growth factor-β to maintain intervertebral disc homeostasis during aging. Bone Research, 6(1), [21]. https://doi.org/10.1038/s41413-018-0022-y