1 Department of Orthopaedic Surgery, Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, The Seventh Affiliated Hospital, Sun Yat-sen University, 518107 Shenzhen, Guangdong, China
2 Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, The First Affiliated Hospital of Sun Yat-sen University, 510060 Guangzhou, Guangdong, China
3 Department of Orthopaedics, The Second Affiliated Hospital of Chongqing Medical University, 400010 Chongqing, China
4 Department of Orthopaedic Surgery, The Affiliated Hospital of Xuzhou Medical University, 221004 Xuzhou, Jiangsu, China
5 Department of Orthopaedics and Trauma, The Affiliated Hospital of Yunnan University, Yunnan University, 650031 Kunming, Yunnan, China
6 Department of Spinal Surgery, The Affiliated Hospital of Qingdao University, 266005 Qingdao, Shandong, China
7 Department of Gynecology and Obstetrics, The Seventh Affiliated Hospital, Sun Yat-sen University, 518107 Shenzhen, Guangdong, China
8 AO Research Institute Davos, 7270 Davos Platz, Switzerland
9 Department of Orthopedics, Fuzhou Second Hospital, 350007 Fuzhou, Fujian, China
* These authors contributed equally as corresponding authors
§ These authors equally contributed to this paper
Abstract
Physical activity shows a positive correlation with overall health, and vigorous intermittent lifestyle physical activity (VILPA) similarly offers advantages in reducing the risk of all-cause mortality. Might the short-time mechanical stimuli be discernible to cells, eliciting commensurate physiological responses? The study's objective was to investigate the cellular response to short-time mechanical stimuli. Human umbilical cord-derived mesenchymal stem cells (hUCMSCs), isolated and thoroughly characterized, were subjected to various stimuli, including activation and mechanical stretching, with Ca2+ influx assessed through alterations in fluorescence intensity. Further validation of these findings was confirmed through short hairpin RNA (shRNA) and inhibitors. In addition, a comprehensive examination of PIEZO1 alterations was conducted through quantitative real-time polymerase chain reaction (qRT-PCR) and western blot (WB) techniques. The results shown different frequencies of stretching stimulation and durations induced varying degrees of Ca2+ influx. The most substantial increase occurred within 2–3 minutes in the group subjected to 0.5 Hz stretching for 2 minutes (p < 0.05). Stretching at 0.5 Hz resulted in significant elevation in PIEZO1 mRNA expression at 15 minutes and 1 hour. Additionally, stretching cause a gradual rise in PIEZO1 protein levels, with a notable peak observed at 2 hours. In conclusion, cells primarily sense short-time mechanical stimuli through PIEZO1, predominantly mediated by regulated Ca2+ influx. This underscores PIEZO1's crucial role in cellular responsiveness to transient mechanical cues, advancing our understanding of mechanosensory mechanisms in cellular physiology.
Graphical Abstract

Keywords
- Vigorous intermittent lifestyle physical activity
- short-time mechanical stimuli
- PIEZO1
- Ca
