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Effect of Low-Intensity Pulsed Ultrasound on the Cartilage Repair in People With Mild to Moderate Knee Osteoarthritis: A Novel Molecular Mechanism
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Letters to the Editor Effect of Low-Intensity Pulsed Ultrasound on the Cartilage Repair in People With Mild to Moderate Knee Osteoarthritis: A Novel Molecular Mechanism I read with great interest the article by Loyola-Sánchez et al1 regarding the effect of low-intensity pulsed ultrasound (LIPUS) on the cartilage repair in osteoarthritis. I would like to complete the discussion of Loyola-Sánchez by introducing a major route in which LIPUS could repair cartilage in osteoarthritis. Recent studies have shown the essential role of interleukin 1 (IL1) in producing osteoarthritis. These studies have revealed the critical effect of IL1 in regulation of the osteoarthritis inflammatory process.2 Therefore, suppression of IL1 activity could reduce osteoarthritis. LIPUS down regulates IL1 production, which can lead to cartilage repair in osteoarthritis.3 Therefore, this effect of LIPUS might contribute as 1 of the major mechanisms for cartilage repair in knee osteoarthritis. Hamid Namazi Shiraz University of Medical Sciences-Shiraz-Iran Shiraz, Islamic Republic of Iran
theory using different ultrasonic parameters (eg, dose, intensity, duty cycle, time, or mode of application) to observe their effects on human cell metabolism and cartilage structure changes. This involves the challenge of defining appropriate methods to measure the mechanism at the molecular, cellular, and tissue levels of human beings specifically in people with cartilage degenerative changes. Moreover, it is not enough to explore the effects of LIPUS at this cartilage impairment level, but it is necessary to understand the impact of the biochemical/cellular/tissue effects on the symptoms, physical capabilities, and social participation of people living with this chronic musculoskeletal condition. In consequence, doing research on the effects of LIPUS on cartilage repair in OA will require transdisciplinary efforts from cell biologists, engineers, health providers, and clinical research methodologists. The urgency to have disease-modifying treatments for OA strongly justifies this multidisciplinary endeavor. Adalberto Loyola-Sánchez, MSc School of Rehabilitation Science McMaster University Hamilton, ON, Canada
Disclosure: No commercial party having a direct financial interest in the results of the research supporting this letter has or will confer a benefit on the authors or on any organization with which the authors are associated.
Julie Richardson, PhD School of Rehabilitation Science McMaster University Hamilton, ON, Canada
References 1. Loyola-Sánchez A, Richardson J, Beattie KA, Otero-Fuentes C, Adachi JD, MacIntyre NJ. Effect of low-intensity pulsed ultrasound on the cartilage repair in people with mild to moderate knee osteoarthritis: a double-blinded, randomized, placebocontrolled pilot study. Arch Phys Med Rehabil 2012;93:35-42. 2. Clérigues V, Guillén MI, Gomar F, Alcaraz MJ. Haem oxygenase-1 counteracts the effects of interleukin-1 on inflammatory and senescence markers in cartilage-subchondral bone explants from osteoarthritic patients. Clin Sci (Lond) 2012;122:239-50. 3. Tsuang YH, Liao LW, Chao YH, et al. Effects of low intensity pulsed ultrasound on rat Schwann cells metabolism. Artif Organs 2011;35:373-83. http://dx.doi.org/10.1016/j.apmr.2012.01.028
The Authors Respond In response to Namazi’s letter, we want to comment that the recent evidence on the positive effects of low-intensity pulsed ultrasound (LIPUS) over the regulation of the proinflammatory interleukin 1 (IL1) verifies the validity of the mechanotransduction theory. This cellular theory explains how living cells convert mechanical stimulus into biochemical responses through a complex process mediated by a large number of extracellular and intracellular structures, such as stretch-activated ion channels and integrins.1 The down regulation of IL1, observed by Tsuang et al,2 can be considered a result of the mechanical stimulation of the cell and its extracellular matrix. This evidence supports the theoretical assumption that LIPUS therapy stimulates the cartilage repair process, stressing the importance of continuing with this line of research, specifically for the development of a disease-modifying treatment for osteoarthritis (OA). This line of research requires incorporating different levels of understanding. It is necessary to test the mechanotransduction Arch Phys Med Rehabil Vol 93, October 2012
Karen A. Beattie, PhD School of Rehabilitation Science and Department of Medicine McMaster University Hamilton, ON, Canada Carmen Otero-Fuentes, MD Department of Radiology McMaster University Hamilton, ON, Canada Jonathan D. Adachi, MD Department of Medicine McMaster University Hamilton, ON, Canada Norma J. MacIntyre, PhD School of Rehabilitation Science McMaster University Hamilton, ON, Canada Disclosure: No commercial party having a direct financial interest in the results of the research supporting this letter has or will confer a benefit on the authors or on any organization with which the authors are associated. References 1. Ingber DE. Cellular mechanotransduction: putting all the pieces together again. FASEB J 2006;20:811-27. 2. Tsuang YH, Liao LW, Chao YH, et al. Effects of low intensity pulsed ultrasound on rat Schwann cells metabolism. Artif Organs 2011;35:373-83.
http://dx.doi.org/10.1016/j.apmr.2012.03.038
DEPARTMENTS
Letters to the Editor Effect of Low-Intensity Pulsed Ultrasound on the Cartilage Repair in People With Mild to Moderate Knee Osteoarthritis: A Novel Molecular Mechanism I read with great interest the article by Loyola-Sánchez et al1 regarding the effect of low-intensity pulsed ultrasound (LIPUS) on the cartilage repair in osteoarthritis. I would like to complete the discussion of Loyola-Sánchez by introducing a major route in which LIPUS could repair cartilage in osteoarthritis. Recent studies have shown the essential role of interleukin 1 (IL1) in producing osteoarthritis. These studies have revealed the critical effect of IL1 in regulation of the osteoarthritis inflammatory process.2 Therefore, suppression of IL1 activity could reduce osteoarthritis. LIPUS down regulates IL1 production, which can lead to cartilage repair in osteoarthritis.3 Therefore, this effect of LIPUS might contribute as 1 of the major mechanisms for cartilage repair in knee osteoarthritis. Hamid Namazi Shiraz University of Medical Sciences-Shiraz-Iran Shiraz, Islamic Republic of Iran
theory using different ultrasonic parameters (eg, dose, intensity, duty cycle, time, or mode of application) to observe their effects on human cell metabolism and cartilage structure changes. This involves the challenge of defining appropriate methods to measure the mechanism at the molecular, cellular, and tissue levels of human beings specifically in people with cartilage degenerative changes. Moreover, it is not enough to explore the effects of LIPUS at this cartilage impairment level, but it is necessary to understand the impact of the biochemical/cellular/tissue effects on the symptoms, physical capabilities, and social participation of people living with this chronic musculoskeletal condition. In consequence, doing research on the effects of LIPUS on cartilage repair in OA will require transdisciplinary efforts from cell biologists, engineers, health providers, and clinical research methodologists. The urgency to have disease-modifying treatments for OA strongly justifies this multidisciplinary endeavor. Adalberto Loyola-Sánchez, MSc School of Rehabilitation Science McMaster University Hamilton, ON, Canada
Disclosure: No commercial party having a direct financial interest in the results of the research supporting this letter has or will confer a benefit on the authors or on any organization with which the authors are associated.
Julie Richardson, PhD School of Rehabilitation Science McMaster University Hamilton, ON, Canada
References 1. Loyola-Sánchez A, Richardson J, Beattie KA, Otero-Fuentes C, Adachi JD, MacIntyre NJ. Effect of low-intensity pulsed ultrasound on the cartilage repair in people with mild to moderate knee osteoarthritis: a double-blinded, randomized, placebocontrolled pilot study. Arch Phys Med Rehabil 2012;93:35-42. 2. Clérigues V, Guillén MI, Gomar F, Alcaraz MJ. Haem oxygenase-1 counteracts the effects of interleukin-1 on inflammatory and senescence markers in cartilage-subchondral bone explants from osteoarthritic patients. Clin Sci (Lond) 2012;122:239-50. 3. Tsuang YH, Liao LW, Chao YH, et al. Effects of low intensity pulsed ultrasound on rat Schwann cells metabolism. Artif Organs 2011;35:373-83. http://dx.doi.org/10.1016/j.apmr.2012.01.028
The Authors Respond In response to Namazi’s letter, we want to comment that the recent evidence on the positive effects of low-intensity pulsed ultrasound (LIPUS) over the regulation of the proinflammatory interleukin 1 (IL1) verifies the validity of the mechanotransduction theory. This cellular theory explains how living cells convert mechanical stimulus into biochemical responses through a complex process mediated by a large number of extracellular and intracellular structures, such as stretch-activated ion channels and integrins.1 The down regulation of IL1, observed by Tsuang et al,2 can be considered a result of the mechanical stimulation of the cell and its extracellular matrix. This evidence supports the theoretical assumption that LIPUS therapy stimulates the cartilage repair process, stressing the importance of continuing with this line of research, specifically for the development of a disease-modifying treatment for osteoarthritis (OA). This line of research requires incorporating different levels of understanding. It is necessary to test the mechanotransduction Arch Phys Med Rehabil Vol 93, October 2012
Karen A. Beattie, PhD School of Rehabilitation Science and Department of Medicine McMaster University Hamilton, ON, Canada Carmen Otero-Fuentes, MD Department of Radiology McMaster University Hamilton, ON, Canada Jonathan D. Adachi, MD Department of Medicine McMaster University Hamilton, ON, Canada Norma J. MacIntyre, PhD School of Rehabilitation Science McMaster University Hamilton, ON, Canada Disclosure: No commercial party having a direct financial interest in the results of the research supporting this letter has or will confer a benefit on the authors or on any organization with which the authors are associated. References 1. Ingber DE. Cellular mechanotransduction: putting all the pieces together again. FASEB J 2006;20:811-27. 2. Tsuang YH, Liao LW, Chao YH, et al. Effects of low intensity pulsed ultrasound on rat Schwann cells metabolism. Artif Organs 2011;35:373-83.
http://dx.doi.org/10.1016/j.apmr.2012.03.038