Low-intensity pulsed ultrasound promotes Schwann cell viability and proliferation via the GSK-3β/β-catenin signaling pathway

Abstract

Background: It has been reported that ultrasound enhances peripheral nerve regeneration, but the mechanism remains elusive. Low-intensity pulsed ultrasound (LIPUS) has been reported to enhance proliferation and alter protein production in various types of cells. In this study, we detected the effects of LIPUS on Schwann cells.Material and methods: Schwann cells were separated from new natal Sprague-Dawley rat sciatic nerves and were cultured and purified. The Schwann cells were treated by LIPUS for 10 minutes every day, with an intensity of 27.37 mW/cm2. After treatment for 5 days, MTT, EdU staining, and flow cytometry were performed to examine cell viability and proliferation. Neurotrophic factors, including FGF, NGF, BDNF, and GDNF, were measured by western blot and real-time PCR. GSK-3β, p-GSK-3β, β-catenin and Cyclin D1 protein levels were detected using a western blot analysis. The expression of Cyclin D1 was also detected by immunofluorescence.Results: MTT and EdU staining showed that LIPUS increased the Schwann cells viability and proliferation. Compared to the control group, LIPUS increased the expression of growth factors and neurotrophic factors, including FGF, NGF, BDNF, GDNF, and Cyclin D1. Meanwhile, GSK-3β activity was inhibited in the LIPUS group as demonstrated by the increased level of p-GSK-3β and the ratio of the p-GSK-3β/GSK-3β level. The mRNA and protein expressions of β-catenin were increased in the LIPUS group. However, SB216763, a GSK-3β inhibitor, reversed the effects of LIPUS on Schwann cells.Conclusion: LIPUS promotes Schwann cell viability and proliferation by increasing Cyclin D1 expression via enhancing the GSK-3β/β-catenin signaling pathway.

Impact of low-intensity pulsed ultrasound on transcription and metabolite compositions in proliferation and functionalization of human adipose-derived mesenchymal stromal cells

“…Xie et al studied human bone marrow stem cells (hBMSCs) and suggested that LIPUS exposure may be involved in the proliferation of hBMSCs through the activation of PI3K/AKT signal pathway 28 . Ren et al studied Schwann cells and showed that LIPUS promoted the activity and proliferation of Schwann cells by enhancing GSK-3β/β-catenin signaling pathways 36 . Budhiraja et al, Xie et al and Ren et al all believed that LIPUS promoted cell proliferation by up-regulating the expression of CyclinD1 27,28,36 CyclinD1 is an early component of cell cycle signaling and binds to Cyclin-dependent Kinase 4 (CDK4), or Cyclin-dependent Kinase 6 (CDK6) to form active complexes.…”

“…Ren et al studied Schwann cells and showed that LIPUS promoted the activity and proliferation of Schwann cells by enhancing GSK-3β/β-catenin signaling pathways 36 . Budhiraja et al, Xie et al and Ren et al all believed that LIPUS promoted cell proliferation by up-regulating the expression of CyclinD1 27,28,36 CyclinD1 is an early component of cell cycle signaling and binds to Cyclin-dependent Kinase 4 (CDK4), or Cyclin-dependent Kinase 6 (CDK6) to form active complexes. This complex leads to a sequence of transcriptional activation and expression www.nature.com/scientificreports/ of cell cycle signaling molecules that drive cells into the next phase of the cell cycle 36 .…”

Low-intensity pulsed ultrasound for regenerating peripheral nerves: potential for penile nerve

“…In 2018, Ren et al . 78 once again confirmed that LIPUS promoted SC viability and proliferation and explored the mechanisms of LIPUS. These authors asserted that the effects of LIPUS were a result of activation of the glycogen synthase kinase 3 beta (GSK-3β)/β-catenin signaling pathway.…”

“…Ren et al . 78 found that in vitro LIPUS promoted SCs secretion of NGF at both the mRNA and protein levels. In 2017, Xia et al .…”

“…Ren et al . 78 found that in vitro LIPUS can promote SCs to secrete BDNF at both the mRNA and protein levels. Contrary to these findings, a study in 2009 77 showed that the mRNA expression of BDNF at the mRNA level was very slightly decreased after LIPUS treatment; these results seem implausible when compared to all other findings.…”