Is Muscle Always Muscle?

TL1 postdoctoral fellow Bahar Shahidi, PhD, DPT, (far right) with her project mentor Sam Ward, PhD, PT, (next to her) and fellow members of the research team at Ward’s lab in the ACTRI building.

Research in Spinal Muscle Lands ACTRI Fellow Shahidi Two NIH Grants

October 17, 2017  |  Patti Wieser

Before embarking on a career in research, Bahar Shahidi, PhD, DPT, was a physical therapist working with patients who had chronic spine issues. The more time she spent in the clinic, the more questions she had that could only be addressed through research. After spending seven years with patients—with a glimpse into research while also working in a neurophysiology research lab on an after-hours project—Shahidi changed her career focus to research and received a PhD in neurophysiology.

As a postdoctoral researcher in 2015, she joined the Radiology and Orthopedic Surgery Departments at UC San Diego, and shortly thereafter was named one of the first TL1 postdoctoral fellows at UC San Diego Altman Clinical and Translational Research Institute (ACTRI). Her two-year TL1 project, “Muscle Structural, Metabolic, and Adaptive Features in Acute and Chronic Disc Herniation,” led to being awarded two NIH grants, an R03 as Principal Investigator and an R01 as Co-Investigator. The R03, a special grant for early career investigators, is $100k per year for two years. It will address the same fundamental goal of improving muscle recovery in low back pain posed in the TL1 study using different tools, while the five-year $1.75 M R01 is a sequel to the TL1. The R01 was awarded in July, and the R03 will be awarded in December. Shahidi also has four publications resulting from the TL1 (see at end of article) and is in the process of interviewing for a faculty position in Orthopaedic Surgery, which would start in the new year.

“Through the TL1 project, we were looking at changes in muscle health in people with acute and chronic spine disease by measuring muscle quality and characterizing the processes of atrophy and cell death,” Shahidi said. “We are interested in structural and metabolic adaptations, as well as the adaptive recovery potential, of muscle tissue in the presence of lumbar spine pathology between acute and chronic disease states.”

A major discovery was that some tissue believed to be muscle is not muscle at all. “From preliminary data, we were finding that the muscles in the lumbar spine are pretty damaged--what we often think looks like muscle by eye is actually fat, fibrosis, and all sorts of extra stuff when we look at it under the microscope. This tissue won’t be able to support the spine like normal healthy muscle, so we are trying to figure out why this happens and how to fix it,” Shahidi said.

The distinction is important in developing therapy for lower back pain, a complex condition that affects 65 to 85 percent of the population. Conventional treatments are physical therapy and surgery. Physical therapy aimed at strengthening muscles, however, is not effective on non-muscle tissue. “If 75 percent of what we think is muscle has no ability to respond to exercise, then what are we actually trying to fix with exercise?” asked Shahidi. “The R03 is a way for us to use some non-invasive tools like advanced MRI to look at muscle activation patterns in people with these damaged lower back muscles and pain.”

The concept is to understand degenerative changes in lumbar spine muscle in order to better define an effective treatment plan. “If we can find out patient-specific prognostic indicators, we can see who will and will not need surgery. For those who do go on to get surgery, who will or will not respond well to that treatment. That information can help us be more strategic about choosing surgery as a treatment option, and perhaps, give us more information about which surgery to choose.” The study, which continues through the new NIH support, includes acute patients through a collaboration with Balgrist University in Zurich, Switzerland, and chronic patients through UC San Diego Health.

Sam Ward, PT, PhD, was Shahidi’s mentor during her TL1 fellowship. “Dr. Shahidi made outstanding contributions to this area of study during her post-doc. A key finding that she made was related to cell death and not simple atrophy in these important muscles, which may be preventing them from recovering, and therefore prohibiting normal spine function in patients. These general ideas were the foundation for her independent funding and will keep her busy for the first few years of a faculty appointment. Support for young investigators is absolutely critical for the mission of translational research at UC San Diego. Financial and intellectual support provides an essential springboard for these bright young scientists at a time when universities' expectations are for new faculty to acquire independent funding almost immediately after appointment. Additionally, this kind of support allows more senior investigators to explore new areas of research by guiding more junior scientists,” Ward said.

Shahidi noted the impact of her experience as a physical therapist on her investigations. “Having clinical experience really helped with contextualizing my research questions,” she said. “I could bring my spine experience, pain experience and clinical experience and take it into a new area--muscle physiology.”

Further enabling her research are UC San Diego and ACTRI. She said UC San Diego places her in the middle of resources that include “amazing people and amazing facilities” and the ACTRI building, where her office is located, gives her access to many disciplines and potential research collaborators.

“This campus gives me the opportunity to diversify and think about a lot of different problems, or to think about one problem in a lot of different ways,” Shahidi said.

Publications resulting, in part, from Shahidi’s TL1 support include:

Lumbar spine postures in Marines during simulated operational positionsJ Orthop Res. 2017

Lumbar multifidus muscle degenerates in individuals with chronic degenerative lumbar spine pathologyJ Orthop Res. 2017

Contribution of Lumbar Spine Pathology and Age to Paraspinal Muscle Size and Fatty InfiltrationSpine (Phila Pa 1976). 2017

SKELETAL MUSCLE ATROPHY AND DEGENERATION IN A MOUSE MODEL OF TRAUMATIC BRAIN INJURYJ Neurotrauma. 2017


About UC San Diego Altman Clinical and Translational Research Institute:

UC San Diego Altman Clinical and Translational Research Institute (ACTRI) is part of a national Clinical and Translational Science Award consortium, led by the National Institutes of Health National Center for Advancing Translational Science. Established in 2010, ACTRI provides infrastructure and support for basic, translational and clinical research throughout the San Diego region to bring discoveries from the laboratory to the bedside, and facilitates training and education of the next generation of researchers. ACTRI carries out its activities in collaboration with institutional and corporate partners and currently has more than 1,425 members.

actri.ucsd.edu