Therapeutic ultrasound stimulation of tendon cell migration.
Ultrasound is a therapeutic agent commonly used to treat sports-related tendinopathy. Tendon healing requires tendon cells migration to the repair site, followed by the proliferation and synthesis of extracellular matrix. This study was designed to determine the effect of ultrasound on migration of tendon cells intrinsic to rat Achilles tendon. Furthermore, the existence of a correlation between this effect and the expression of the contractile actin isoform, alpha-smooth muscle (SM) actin, which is associated with cell mobility, was also examined. Cell migration was evaluated by transwell filter migration assay. The mRNA expressions of alpha-SM actin were determined by reverse transcription-polymerase chain reaction. Dose-dependent ultrasound enhancement of tendon cells migration through the transwell filter was demonstrated. Using immunofluorescence stain for alpha-SM actin, the percentages of alpha-SM actin-positive cells of total cells, nonmigrated cells, and migrated cells on the filter were calculated. Ultrasound-treated cells which had migrated to the bottom side of the filter were more likely to express alpha-SM actin than migrated control cells and nonmigrated cells. However, there was no change of mRNA and protein expression of alpha-SM actin as well as expression of FAK and p-FAK. In conclusion, ultrasound stimulates tendon cell migration in association with increased expression of alpha-SM actin of tendon cells.
Tsai
Wen-Chung
WC
Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, and College of Medicine, Chang Gung University, Taoyuan, Taiwan. tsaiwc@adm.cgmh.org.tw
Chen
Jannie Ying-Syuan
JY
Pang
Jong-Hwei S
JH
Hsu
Chih-Chin
CC
Lin
Miao-Sui
MS
Chieh
Liang-Wei
LW
D000199:Actins / Q000378:metabolism*; D000818:Animals; D002465:Cell Movement / Q000502:physiology*; D002478:Cells, Cultured; D051417:Focal Adhesion Kinase 1 / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D052256:Tendinopathy / Q000473:pathology / Q000628:therapy*; D013710:Tendons / Q000473:pathology / Q000502:physiology*; D014464:Ultrasonic Therapy
C558396:Acta2 protein, mouse; D000199:Actins; D012333:RNA, Messenger; D051417:Focal Adhesion Kinase 1; C496052:Ptk2 protein, rat