Poster #105, Cedars Sinai Medical Center
Generation of Nucleus Pulposus-like Cells from iMSCs and Comparison with Developmental iPSC-derived iNPCs
Mentors: Tynhinane Hamidouche, PhD and Dimitry Sheyn, PhD
Degenerative disc disease (DDD) is a leading cause of chronic low back pain, affecting approximately 16 million adults in the United States. It is characterized by progressive degeneration of the nucleus pulposus (NP), the gelatinous core of the intervertebral disc responsible for maintaining hydration and mechanical function. Loss of NP cells and extracellular matrix (ECM) leads to disc degeneration, impaired biomechanical function, and chronic lower backpain. During embryonic development, the NP originates from the notochord; however, in humans, notochordal cells progressively disappear during childhood, leaving the adult NP with limited regenerative capacity. Although stem cell-based therapies have emerged as promising strategies for disc regeneration, most current differentiation approaches do not recapitulate the developmental transition through the notochord. We therefore hypothesize that mimicking this developmental pathway will enhance the generation of matrix-producing NP-like cells. Our laboratory established a developmental differentiation platform capable of generating NP-like cells from human induced pluripotent stem cells (iPSCs) through an induced notochordal cell (iNC) intermediate. Using an ACAN-mCherry reporter iPSC line, which enables real-time monitoring of aggrecan expression during differentiation, preliminary studies demonstrated successful NP-like differentiation and expression of NP-associated markers. Building on these findings, the objective of the current study is to compare NP differentiation through the developmental iNC pathway with a conventional induced mesenchymal stem cell (iMSC) pathway. Human iPSCs are differentiated into either iNCs or iMSCs before NP induction using TGF-β1 and GDF5. NP differentiation is evaluated by monitoring ACAN-mCherry reporter activity, cell morphology, and expression of NP-specific genes by quantitative PCR. This study will establish a framework for directly comparing notochordal and mesenchymal differentiation strategies for generating NP-like cells. The findings will provide insight into whether recapitulating notochord development improves NP differentiation and may guide the development of more effective stem cell-based therapies for intervertebral disc regeneration.