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Ryan Christopher Riddle, Ph.D.

Headshot of Ryan Christopher Riddle
  • Associate Professor of Orthopaedic Surgery

Research Interests

Musculoskeletal development, Skeletal metabolism, Wnt signaling more


Dr. Ryan Riddle is an assistant professor of orthopaedic surgery at the Johns Hopkins University School of Medicine.  He earned his Ph.D. from Pennsylvania State University College of Medicine and completed postdoctoral fellowships at the University of Alabama at Birmingham and Johns Hopkins University School of Medicine.

Dr. Riddle’s research focuses on Wnt/b-catenin signaling in musculoskeletal development and in response to mechanical, hormonal, and other anabolic signals. His prior work examined skeletal mechanotransduction—the process in which mechanical signals are translated to biochemical signals.

He is a member of the American Society for Bone & Mineral Research and the Endocrine Society. His work has been recognized with a 2011-2012 Musculoskeletal Pilot and Feasibility Grant from the JHU Center for Musculoskeletal Research and is supported by grants from the Veterans Administration and the National Institutes of Health. more


  • Associate Professor of Orthopaedic Surgery

Departments / Divisions



  • B.S.; Loyola University (Maryland) (2002)
  • Ph.D.; Pennsylvania State University (Pennsylvania) (2007)

Additional Training

  • University of Alabama, Birmingham, AL, 2007

Research & Publications

Research Summary

Research in Dr. Riddle’s laboratory is focused on Wnt/b-catenin signaling in musculoskeletal development.  He utilizes mouse genetics to examine receptor and intracellular signaling mechanisms.  In one project, he is interested in the unique and overlapping functions of Wnt signaling components in the accrual of bone and muscle mass.  The Wnt pathway consists of 10 highly related Frizzled receptors, two co-receptors, and several ligands that activate signaling, and human mutations that modify signaling efficacy are associated with both high and low bone mass phenotypes.  Using transgenic mice lacking Wnt signaling components in bone or muscle cells, his research seeks to determine the requirement for this signaling pathway during bone and muscle development and in the response to mechanical, hormonal, and other anabolic signals.  In a second, but related project, his laboratory has found that mice lacking the Wnt co-receptor, low density lipoprotein-related receptor-5, in osteoblasts accumulate body fat and develop dyslipidemia.  These findings have led to new studies designed to examine the energetic requirements of bone cells and to determine how the skeleton communicates its metabolic needs to other tissues.

Selected Publications

View all on PubMed

Riddle RC, Clemens TL. Bone cell bioenergetics and skeletal energy homeostasis. Physiol Rev. 2017 April;97(2):667-698. doi: 10.1152/physrev.00022.2016. Review.

Ziegler SG, Ferreira CR, MacFarlane EG, Riddle RC, Tomlinson RE, Chew EY, Martin L, Ma CT, Sergienko E, Pinkerton AB, Millán JL, Gahl WA, Dietz HC. Ectopic calcification in pseudoxanthoma elasticum responds to inhibition of tissue-nonspecific alkaline phosphatase. Sci Transl Med. 2017 Jun 7;9(393). pii: eaal1669. doi: 10.1126/scitranslmed.aal1669.

Tomlinson RE, Li Z, Li Z, Minichiello L, Riddle RC, Venkatesan A, Clemens TL. NGF-TrkA signaling in sensory nerves is required for skeletal adaptation to mechanical loads in mice. Proc Natl Acad Sci U S A. 2017 May 2;114(18):E3632-E3641. doi: 10.1073/pnas.1701054114. Epub 2017 Apr 17.

Li Z, Frey JL, Wong GW, Faugere MC, Wolfgang MJ, Kim JK, Riddle RC, Clemens TL. Glucose Transporter-4 Facilitates Insulin-Stimulated Glucose Uptake in Osteoblasts. Endocrinology. 2016 Nov;157(11):4094-4103. Epub 2016 Sep 30.

Zoch ML, Abou DS, Clemens TL, Thorek DL, Riddle RC. In vivo radiometric analysis of glucose uptake and distribution in mouse bone. Bone Res. 2016 Apr 5;4:16004. doi: 10.1038/boneres.2016.4. eCollection 2016.

Contact for Research Inquiries

Orthopaedic Research Labs
720 Rutland Avenue
Ross Research Building
Baltimore, MD 21205 map

Academic Affiliations & Courses

Graduate Program Affiliation

Cellular and Molecular Medicine

Activities & Honors


  • Musculoskeletal Pilot and Feasibility Grant, JHU Center for Musculoskeletal Research, 2011
  • Career Development Award, Veterans Administration, 2011
  • Young Investigator Award, American Society for Bone and Mineral Research


  • American Society for Bone & Mineral Research
  • International Bone & Mineral Society
  • Endocrine Society
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