1. Academic Validation
  2. Matrix stiffness regulates nucleus pulposus cell glycolysis by MRTF-A-dependent mechanotransduction

Matrix stiffness regulates nucleus pulposus cell glycolysis by MRTF-A-dependent mechanotransduction

  • Bone Res. 2025 Feb 14;13(1):23. doi: 10.1038/s41413-025-00402-7.
Haoran Xu # 1 2 Kang Wei # 3 Jinhao Ni # 1 Xiaofeng Deng 4 Yuexing Wang 1 Taiyang Xiang 1 Fanglong Song 1 Qianliang Wang 1 Yanping Niu 1 Fengxian Jiang 1 Jun Wang 5 Lei Sheng 6 Jun Dai 7
Affiliations

Affiliations

  • 1 Department of Orthopedic Surgery, The Second Affiliated Hospital of Soochow University, Suzhou, China.
  • 2 Department of Orthopedic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
  • 3 Department of Plastic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China.
  • 4 Department of Rehabilitation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
  • 5 State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Periodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China. junwang@scu.edu.cn.
  • 6 Department of Orthopedic Surgery, The Second Affiliated Hospital of Soochow University, Suzhou, China. shenglei510@suda.edu.cn.
  • 7 Department of Orthopedic Surgery, The Second Affiliated Hospital of Soochow University, Suzhou, China. daijun@suda.edu.cn.
  • # Contributed equally.
Abstract

Increased matrix stiffness of nucleus pulposus (NP) tissue is a main feature of intervertebral disc degeneration (IVDD) and affects various functions of nucleus pulposus cells (NPCs). Glycolysis is the main energy source for NPC survival, but the effects and underlying mechanisms of increased extracellular matrix (ECM) stiffness on NPC glycolysis remain unknown. In this study, hydrogels with different stiffness were established to mimic the mechanical environment of NPCs. Notably, increased matrix stiffness in degenerated NP tissues from IVDD patients was accompanied with impaired glycolysis, and NPCs cultured on rigid substrates exhibited a reduction in glycolysis. Meanwhile, RNA Sequencing analysis showed altered cytoskeleton-related gene expression in NPCs on rigid substrates. Myocardin-related transcription factor A (MRTF-A) is a transcriptional coactivator in mechanotransduction mainly responding to Cytoskeleton remodeling, which was activated and translocated to the nucleus under rigid substrate and was upregulated during IVDD progression. Furthermore, gas chromatography-mass spectrometry (GC-MS) analysis revealed that MRTF-A overexpression reduced NPC glycolytic metabolite abundance and identified a correlation with AMPK pathway. Mechanistically, rigid substrates and MRTF-A overexpression inhibited Kidins220 expression and AMPK phosphorylation in NPCs, whereas MRTF-A inhibition, treated with the MRTF-A inhibitor CCG, partially rescued NP tissue degeneration and glycolytic Enzyme expression. Our data demonstrate that MRTF-A is a critical regulator that responds to increased matrix stiffness in IVDD, and MRTF-A activation reduces NPC glycolysis by down-regulating Kidins220 and inhibiting AMPK phosphorylation.

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