Biological effects of low-intensity ultrasound on dental stem cells

Gao, Qianhua (2016). Biological effects of low-intensity ultrasound on dental stem cells. University of Birmingham. Ph.D.

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Abstract

The value of low-intensity pulsed ultrasound (LIPUS) in regeneration of the dental tissue has not been fully investigated. This investigation aim to research the effects of LIPUS on dental stem cells, and specify the role of signalling pathways in regulating stem cell responses. Dental pulp stem cells (DPSCs), periodontal ligament stem cells (PDLSCs), and bone marrow stem cells (BMSCs) were isolated from Wistar rats. LIPUS significantly increased cell growth and proliferation of DPSCs, PDLSCs and BMSCs. In DPSC, ERK1/2 was activated immediately, whereas ERK1/2 inhibition modulated the proliferation effects. In BMSC, JNK MAPK was activated, and the post-LIPUS proliferation was decreased by JNK inhibition. In PDLSC, JNK MAPK was activated immediately post-treatment, and p38 MAPK was activated until 1 hour. Subsequently, specific JNK and p38 inhibition decreased proliferation effects after LIPUS. Piezo1/2 were up-regulated post-treatment in DPSC, but not statistically significant in PDLSC. Ruthenium Red, an inhibitor of Piezo1/2, only inhibited ERK1/2 activation, but not JNK or p38 MAPK. Furthermore, when Piezo1/2 were inhibited before LIPUS exposure, it modulated the increase of proliferation in DPSC, not in PDLSC. In conclusion, LIPUS does promote proliferation of dental stem cells; The proliferation of dental stem cells is dependent on MAPK signalling, and there was variation in different MSC lineages; LIPUS may also have an effect on ion channels such as Piezo1/2. Such mechanically activated mechanisms have implications for future stem cell-based dental tissue regeneration.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

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