“Modeled Osteopathic Manipulative Treatments: A Review of their in Vitro Effects on Fibroblast Tissue Preparations”; Manal Zein-Hammoud, PhD and Paul Standley, PhD; The Journal of the American Osteopathic Association; August 2015, vol. 115, Number 8, pp. 490-501.
The authors’ in vitro work has focused on modeling 2 common OMT modalities: Myofascial Release and Counterstrain. Their studies have evaluated the effects of these modalities on wound healing, cytokine secretion and muscle repair. The key components of the host response to mechanical forces are fibroblasts, which are the main fascial cells that respond to different types of strain by secreting anti-inflammatory chemicals and growth factors, thus improving wound healing and muscle repair processes. The purpose of this review is to discuss the cellular and molecular mechanisms by which MFR and CS work on fibroblasts. If the results of these studies are clinically translatable, the mechanisms underlying clinical outcomes of OMT modalities will be better understood.
Above is the summary of this article. Now, I’ll outline the different in vitro studies they review and the findings:
“One thing common to both deleterious repetitive motion strain (RMS) and curative OMT is biomechanical stimulation. This connection catalyzed our laboratory to investigate how various biomechanical strains modeling both RMSs and various OMT modalities affect cellular physiology and gene activation and suppression.”
The fibroblast is the principle cell type of the fasciae that synthesizes, organizes and remodels collagen. It is the target for normal and abnormal biomechanical stimuli. These in vitro studies have shown that fibroblasts respond to strain by secreting proinflammatory and anti-inflammatory cytokines, undergoing hyperplasia as well as altering cell shape and alignment.
Fibroblasts respond to injury by rapid proliferation at the site of injury, forming granulation tissues and providing structural integrity to the wound. Events that constitute the wound healing process include cellular proliferation, migration, extracellular matrix deposition, and remodeling. By manipulating the fasciae, OMT targets fibroblasts.
The article then discusses direct, indirect and combination OMT techniques and states that a key commonality of all OMT techniques is that they were designed to impart biomechanical stimuli to affected or associated tissues to bring about change in the cellular function.
The in vitro studies they have done have focused on stretching and compressing fibroblasts TO BEGIN an analysis of potential cell and tissue effects that may explain patients’ improvements after OMT. (Isn’t this AWESOME!)
They then explain that over the last 10 or more years they have developed three different in vitro models in which to study the effect of magnitude and duration of strain as well as the direction and frequency of strain on fibroblasts:
- 2-dimensional fibroblast matrix
- 3-dimensional fibroblast matrix dubbed a “bioengineered tendon(BET)”
- Co-culture that allows interaction between fibroblasts and myoblasts to create a modeled myofascial junction.
In their earliest studies they explored the effect that acyclic in vitro biophysical strain has on cellular shape, proliferation on fibroblasts, nitric oxide (NO) production, interleukin 1 (IL-1) and interleukin 6 (IL-6) secretion.
Acyclic strain was applied in a heterobiaxial manner (unequal strains in both axes) in magnitudes from 10% to 30% beyond resting length for durations ranging from 12 to 72 hours. The results showed that strain magnitude of 10% for 48 and 72 hours induced mild cellular rounding and pseudopodia truncation compared with the spindle-shaped and well-defined pseudopodia of the control non-strained fibroblasts. Interleukin 1 secretion did not change, but interleukin 6 secretion and nitric oxide levels did increase in the strained cells.
Further, strain magnitude of 30% caused reduced cell viability, cell membrane decomposition and pseudopodia loss. These first studies showed that biomechanical strain had profound effects on several cellular processes such as proliferation, apoptosis, and cytokine production.
They also investigated the role of strain direction comparing equibiaxial strain to heterobiaxial strain effects and found that heterobiaxial strain had an effect on fibroblast morphology and cellular proliferation more than equibiaxial strain.
Tune in next week and I will continue to review the findings of Dr. Standley’s work on fibroblasts and its possible connection to OMT.