Effects of low-magnitude high-frequency vibration on proliferation and cartilage phenotype of chondrocytes in the rat mandibular condyle.
Source: PubMed, NCBI / U.S. National Library of Medicine
This study explored low-magnitude high-frequency (LMHF) mechanical vibration as a strategy to expand mandibular condylar chondrocyte (MCC) populations with enhanced chondrogenic phenotypes, providing high-quality cellular resources for cartilage tissue engineering. Primary MCCs from 3-week-old Sprague-Dawley rat condylar cartilage were subjected to LMHF vibration stimulation (0.49 g, 40 Hz) using a GJX-5 vibration device. Cell proliferation was evaluated via lactate dehydrogenase (LDH) assay and flow cytometry-based cell cycle analysis. The maintenance and enhancement of the chondrogenic phenotype were determined by enzyme-linked immunosorbent assay (ELISA) for glycosaminoglycan (GAG) secretion and Western blotting for the expression of key markers, including Aggrecan (AGG), bone morphogenetic protein 7 (BMP7), Collagen X, β-catenin, and the autophagy-related protein Atg12. Additionally, alkaline phosphatase (ALP) activity was measured to assess chondrocyte maturation. LMHF vibration exerts no significant effect on the proliferation of MCCs, and its regulatory effect is mostly manifested as a time-dependent pattern. Compared with the control group, LMHF vibration reduced MCC proliferation on Days 1 and 3 but increased it on Day 5, with increased S-phase fraction (SPF)(P < 0.001). ALP activity rose continuously in the vibration group, peaking on day 14. The vibration group showed a 56.5% increase in GAG secretion on day 3 (P < 0.
Abstract
This study explored low-magnitude high-frequency (LMHF) mechanical vibration as a strategy to expand mandibular condylar chondrocyte (MCC) populations with enhanced chondrogenic phenotypes, providing high-quality cellular resources for cartilage tissue engineering. Primary MCCs from 3-week-old Sprague-Dawley rat condylar cartilage were subjected to LMHF vibration stimulation (0.49 g, 40 Hz) using a GJX-5 vibration device. Cell proliferation was evaluated via lactate dehydrogenase (LDH) assay and flow cytometry-based cell cycle analysis. The maintenance and enhancement of the chondrogenic phenotype were determined by enzyme-linked immunosorbent assay (ELISA) for glycosaminoglycan (GAG) secretion and Western blotting for the expression of key markers, including Aggrecan (AGG), bone morphogenetic protein 7 (BMP7), Collagen X, β-catenin, and the autophagy-related protein Atg12. Additionally, alkaline phosphatase (ALP) activity was measured to assess chondrocyte maturation. LMHF vibration exerts no significant effect on the proliferation of MCCs, and its regulatory effect is mostly manifested as a time-dependent pattern. Compared with the control group, LMHF vibration reduced MCC proliferation on Days 1 and 3 but increased it on Day 5, with increased S-phase fraction (SPF)(P < 0.001). ALP activity rose continuously in the vibration group, peaking on day 14. The vibration group showed a 56.5% increase in GAG secretion on day 3 (P < 0.01), upregulated the expression of chondrogenic markers (AGG, BMP7, Collagen X), and downregulated the autophagy-related protein Atg12 (P < 0.05). Appropriate LMHF mechanical vibration (0.49 g, 40 Hz) effectively enhances the chondrogenic phenotype of MCCs. This non-invasive strategy holds significant promise for cartilage tissue engineering and chondrocyte-based therapy.