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Crichton Bagnara A1, Bacigalupo Osorio G1, Osses Rivera N2
1Pontifical Catholic University of Valparaíso, School of Kinesiology, Science Faculty, Valparaiso, Chile, 2Pontifical Catholic University of Valparaíso, Institute of Chemistry, Science Faculty, Valparaiso, Chile
Background: Therapeutic Ultrasound (US) had been used widely in physiotherapy with different purpose including the treatment of skeletal muscle injuries. For functional muscle regeneration is required the fusion of myoblast to form multinucleated myotubes. Different studies have evaluated the effect of therapeutic ultrasound on skeletal muscle differentiation, however the effect of continuous compare to pulsed modes in myotubes formation is unclear.
Purpose: The main purpose of this in vitro study was to evaluate the effects of doses and modality of therapeutic ultrasound on C2C12 myoblast morphological differentiation.
Methods: We used C2C12 myoblast, a well stablished skeletal muscle cell line, to evaluate the efficacy of a therapeutic ultrasonic device commonly used in clinical practice (Sonopuls 492, Enraf Nonius®) on morphological differentiation (myotube formation). We applied different ultrasound doses (150 or 300 Joules) and modalities (100% or 20% duty cycle) for consecutive days at 0.4 w/cm2 (ISPTA). Microscopy was used to analyze different parameters of morphological differentiation including number of myotubes, fusion index and distribution of nuclei per myotubes. In addition, creatine kinase (CK) activity was evaluated as a biochemical marker of muscle differentiation. All the experiments were performed at least three independent times and p 0.05 was considered as significant.
Results: We found that pulsed ultrasound (20% Duty cycle) at 300J increases CK activity and induce formation of myotubes with more nuclei than control and 150J treated cells. Time course of myotubes formation shown that, pulsatile US at 300J significantly increase number of myotubes, fusion index and nuclei per myotubes.
Conclusion(s): Pulsed therapeutic ultrasound enhances muscle differentiation of C2C12 myoblast in a dose depend form generating myotubes with more nuclei content.
Implications: We provide evidence to support the benefit of pulsed therapeutic ultrasound in the formation of robust myotubes and the potential application in the field of skeletal muscle tissue repair.
Keywords: Therapeutic ultrasound, muscle regeneration, myotubes
Funding acknowledgements: Vice-rectroria of research and advanced studies (VRIEA-PUCV).
Purpose: The main purpose of this in vitro study was to evaluate the effects of doses and modality of therapeutic ultrasound on C2C12 myoblast morphological differentiation.
Methods: We used C2C12 myoblast, a well stablished skeletal muscle cell line, to evaluate the efficacy of a therapeutic ultrasonic device commonly used in clinical practice (Sonopuls 492, Enraf Nonius®) on morphological differentiation (myotube formation). We applied different ultrasound doses (150 or 300 Joules) and modalities (100% or 20% duty cycle) for consecutive days at 0.4 w/cm2 (ISPTA). Microscopy was used to analyze different parameters of morphological differentiation including number of myotubes, fusion index and distribution of nuclei per myotubes. In addition, creatine kinase (CK) activity was evaluated as a biochemical marker of muscle differentiation. All the experiments were performed at least three independent times and p 0.05 was considered as significant.
Results: We found that pulsed ultrasound (20% Duty cycle) at 300J increases CK activity and induce formation of myotubes with more nuclei than control and 150J treated cells. Time course of myotubes formation shown that, pulsatile US at 300J significantly increase number of myotubes, fusion index and nuclei per myotubes.
Conclusion(s): Pulsed therapeutic ultrasound enhances muscle differentiation of C2C12 myoblast in a dose depend form generating myotubes with more nuclei content.
Implications: We provide evidence to support the benefit of pulsed therapeutic ultrasound in the formation of robust myotubes and the potential application in the field of skeletal muscle tissue repair.
Keywords: Therapeutic ultrasound, muscle regeneration, myotubes
Funding acknowledgements: Vice-rectroria of research and advanced studies (VRIEA-PUCV).
Topic: Electrophysical & isothermal agents; Musculoskeletal; Sport & sports injuries
Ethics approval required: No
Institution: N/A
Ethics committee: N/A
Reason not required: The nature of this study is of in vitro characteristics
All authors, affiliations and abstracts have been published as submitted.
