THE SYSTEMIC EFFECTS OF EXERCISE IN PRE-PUBERTAL GIRLS AND WOMEN ON MUSCLE AND BONE GROWTH IN VITRO: TRANSLATING PEDIATRIC EXERCISE SCIENCE WITH ANIMATION Ph.D. Thesis – Y. Mezil McMaster University – Medical Sciences THE SYSTEMIC EFFECTS OF EXERCISE IN PRE-PUBERTAL GIRLS AND WOMEN ON MUSCLE AND BONE GROWTH IN VITRO: TRANSLATING PEDIATRIC EXERCISE SCIENCE WITH ANIMATION By Yasmeen Mezil H.B.Sc., M.Sc. A Thesis Submitted to the School of Graduate Studies in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy McMaster University © Copyright by Yasmeen Mezil, March 2020 1 i Ph.D. Thesis – Y. Mezil McMaster University – Medical Sciences Doctor of Philosophy (2020) McMaster University (Medical Sciences) Hamilton, Ontario TITLE: The systemic effects of exercise in pre- pubertal girls and women on muscle and bone growth in vitro: Translating pediatric exercise science with animation AUTHOR: Yasmeen Mezil, H.B.Sc (Brock University), M.Sc. (Brock University) SUPERVISOR: Dr. Brian W. Timmons, Ph.D. NUMBER OF PAGES: 300 ii Ph.D. Thesis – Y. Mezil McMaster University – Medical Sciences ABSTRACT The systemic environment in children is characterized by factors that facilitate muscle and bone development. These systemic factors may help to regulate the growth of these tissues particularly when mechanical loading is minimal, as observed with low-impact exercise. Low-impact exercise induces an alteration in the systemic environment in children and adults, however the direct implications of these changes on muscle and bone development are unclear. The focus of this thesis was to examine the effects of exercise on systemic regulators of muscle and bone growth in prepubertal girls and women, and to determine whether changes in these systemic regulators can influence osteoblast and myoblast proliferation and differentiation. In addition, this thesis will also highlight the importance of translating knowledge in the form of an animation video about the effects of exercise on bone health. Our first study demonstrated that an acute bout of moderate intensity exercise elicits similar responses in systemic regulators (CX3CL1, FGF-2, and IGF-1) of muscle and bone growth in prepubertal girls and women, with exception of a higher inflammatory response (IL-6) in women. In our second study, we show that exercise does not elicit a proliferative response myoblasts and osteoblasts in vitro after treatment with serum collected from prepubertal girls and women. However, iii Ph.D. Thesis – Y. Mezil McMaster University – Medical Sciences proliferation of osteoblasts and myoblasts was higher in women post- exercise relative to prepubertal girls. Moreover, there was no exercise effect on myotube formation in prepubertal girls and women, however mineralization decreased post-exercise in both groups. In our final study, we developed an animation video that summarizes the findings of this thesis to school-age children and explored the educational utility of this knowledge translation tool. Four salient viewpoints were identified in our cohort of children, each with varying degrees of engagement and attitudes towards the video. All participants expressed an improved understanding how exercise influences bone as evidenced by their consensus statement. Altogether, our data suggests that inflammatory responses induced by exercise are attenuated in children relative to adults, which can have an effect on myoblast and osteoblast proliferation. The decrease in mineralization observed after exercise may be indicative of increased bone remodeling followed by an anabolic bone response. Finally, the development of a knowledge translation tool proved to be feasible and beneficial in promoting awareness about the benefits of exercise on bone health. iv Ph.D. Thesis – Y. Mezil McMaster University – Medical Sciences AKNOWLEDGEMENTS In the name of God, the Most Gracious, the Most Merciful. This thesis has been an incredible journey, one that I have had the privilege to share with several individuals. I would first like to thank my supervisor, Dr. Brian Timmons. Thank you so much for your mentorship, guidance, and support throughout this journey. I appreciate all of the opportunities you have given me to thrive as a researcher, as well as the challenges you have tested me with. You have inspired me to push my limits and work outside of my comfort zone, which has translated into aspects beyond my research. It has been an honour working with you. I would like to express a sincere thank you to my supervisory committee, Dr. Sandeep Raha and Dr. Thomas Hawke. Thank you for challenging me with questions and teaching me to consider the implications of my experiment designs. Your guidance and support have been pivotal to my experience as a researcher, thank you for keeping your doors open. I would also like to recognize Dr. Joyce Obeid. Thank you for teaching me the how-to’s of pediatric exercise testing, answering my many questions, and being there to listen. You have been an amazing colleague, friend, and of course my super-hero on multiple occasions, and for that I am grateful. In addition to my mentors, I have been very fortunate to work with incredible individuals during my thesis. I would like to thank my MBU team: Alexis Bullock, Evelina Zebrowski, and Kylee Innes. Thank you helping me launch this project and for spending many hours with me in the lab. Despite the challenges, you continued to be enthusiastic, positive, and cooperative in every step of the way – working with you has truly been a wonderful experience. I would also like to thank the fabulous cast of Exercise Messengers: Rowan Timmons, Carson Timmons, Atticus Singh, and Inna Ushcatz. Your curiosity, perfectionism, and wonderful voices brought my vision to life! Thank you for giving the script your all, I could have not asked for a better cast. To the past and present members of the CHEMP Lab: Dr. Thanh Nguyen, Dr. Gabriela Leites, Dr. Lisa Chu, Dr. David Allison, Dr. Sara King- v Ph.D. Thesis – Y. Mezil McMaster University – Medical Sciences Dowling, Dr. Nicole Proudfoot, Hilary Caldwell, Natascja D'Almonte, Inna Ushcatz, Maddy Byra, Mila Bjelica, Roxy Chen, Bhanu Sharma, Elizabeth Fonseca, and Meighan Colterjohn – thank you for your tremendous support throughout this journey. You have helped me in numerous ways, from promoting recruitment, volunteering to be practise subjects, to providing moral support - it was worth every Beechwood donut. I am incredibly lucky to have had an amazing lab family, thank you. To my adoptive lab family, the Raha Lab: Dr. Michael Wong, Ol’Lenecia Sauvé, Chitman Josan, Jodi Rabeneck, Pat Rodriquez, and Robyn Perreira – thank you for treating me as one of your own, giving me the title of the corner desk, and sharing your cell culture wisdom with me. I will always look back to the wonderful times we have spent together in the wet lab and beyond. I would also like to thank individuals who have lent their expertise over the course of my thesis. To Dr. Dhuha Al-Sajee, Dr. Henry Schwarcz, Aaron Hubbell, and Dr. Andrea Cross – thank you for addressing my questions about microscopy, mineralization, knowledge translation, and animation design! I appreciate the time you took to show me the ropes, and I am thankful to have crossed paths with every one of you. To the Anatomy team: Dr. Vickie Galea, Dr. Bruce Wainman, Dr. Kristina Durham, Dr. Danielle Brewer-Deluce, and Efrah Yousuf – thank you for showing me the art of teaching and providing me with the opportunity to express my admiration for the wonders of the human body! You have helped me become a better educator, and with that a better researcher. I would also like to thank my graduate peers who have contributed greatly to my proactive journey outside of the lab through the Gallery of Graduate Arts, Industry Link, and Graduate Muslim Students Association: Irena Radisevic, Dr. Sonia Padwal, Dr. Tanya Miladinovic, Dr. William Gwynne, Dr. Athan Dial, Chitman Josan, Dr. Amanda Lee, Dr. Michael Wong, Dr. Khaled Yehia, Dr. Basma Ahmed, Dr. Mohammad Hammuda, and Khaqan Majeed. Thank you for being my community, helping me a grow as a team player and leader, and for reminding me of all the wonderful ways we can serve our fellow graduate students. A special shout out to Andrea Cole, Pete Self, and Correen Smith from SGS for granting us an opportunity to SPICE things up! vi Ph.D. Thesis – Y. Mezil McMaster University – Medical Sciences To my wonderful friends beyond the lab who have shown me their continuous support throughout my thesis: Dr. Izabella Ludwa, Dr. Tamadher Al-Ghamdi, Ala Mohamed, Shazia Khan, Fatima Benhalim, Amal Karam, and Hanin Hamad. Thank you for listening and checking in – you have never failed to do so even at times I felt shorthanded in our friendship. You have been an incredible support; I hope to be there for you just as much as you have been there for me. Lastly and certainly not least, I am most grateful to my family: Addel, Ahmed, Baba and Mama. This journey was filled with ups and downs, and you were there for every second of it. Thank you for making me smile and laugh, for mastering the art of asking about my PhD, and for caring for me in the most endearing and powerful of ways. To Mama, thank you for everything. You are my best friend, my impeccable role model, and the light of my life. Thank you for pushing me to believe in myself and make it to the finish line. This is our PhD thesis, and my success is your success. I love you, habibti Mama. vii Ph.D. Thesis – Y. Mezil McMaster University – Medical Sciences I recognize and acknowledge that the work pertained in this thesis was conducted on the traditional territories of the Mississauga and Haudenosaunee nations, and within the lands protected by the “Dish with One Spoon” wampum agreement.