Purpose

Hyaluronic acid (HA), platelet-rich plasma (PRP), and methylprednisolone are widely used to manage osteoarthritis (OA). More recently, human bone marrow derived mesenchymal stem cells (BM-MSCs) have garnered interest as a non-operative means for OA symptom modification. Anti-inflammatory cytokine secretion is a major component of BM-MSC action. We sought to describe the effect of HA, PRP, and methylprednisolone on the cytokine profile of BM-MSCs at multiple stages of culture expansion.

Methods and Materials

Nine BM-MSC cell lines from 4 human donors underwent three stages of culture expansion: passage 2 (P2), passage 3 (P3), and passage 4 (P4). Levels of OA-related cytokines (IL-1β, IL-6, IL-8, IL-10, Stem cell Factor [SCF], Stem Cell Derived Factor-alpha [SDF-α]) were measured using Luminex multiplexing technology. The BM-MSC preparations were evaluated at each passage, 24 hours following exposure to HA, PRP, or methylprednisolone.

Results

Culture expansion altered cytokine production, however treatment with OA therapeutics further altered these responses implicating the potential of combined treatment of culture expanded hMSCs and OA therapeutics. Figure 1 demonstrates the behavior of cytokines after exposure to HA, PRP or methylprednisolone. Further, we tested different concentrations of the therapeutics to determine optimal dosing.

Exposure to increasing doses of HA reduced BM-MSC expression of SCF, SDF-α, VEGF, CCL20, and adiponectin (p<0.05 for all). PRP increased IL-1 levels in P2 and P3 (p<0.05 for both), IL-6 in P2 (100 pg/mL vs 5500 pg/mL, p<0.001), and IL-8 in P3 (900 pg/mL vs 3900 pg/mL, p<0.001). PRP did not affect IL-10 expression (p>0.05). Aside from an increase in IL-6 production for P2 (200 pg/mL vs 1500 pg/mL, p<0.05), methylprednisolone did not affect cytokine expression.

Conclusion

Orthopaedic therapeutic adjuvants influence the inflammatory cytokine profile of BM-MSCs at multiple stages of culture expansion. These therapeutics have potential to be used with BM-MSCs to create an optimal cytokine environment for treatment of degenerative joint disease.

Purpose

Biologic treatments for articular cartilage injury and degenerative joint disease are increasing in demand by active patients. Human bone marrow derived mesenchymal stem cells (BM-MSCs) have garnered interest as a treatment for their ability to differentiate into cells of chondrogenic lineage and their production of cytokines and/or growth factors. Culture expansion of BM-MSCs has the potential to enhance these capabilities. During expansion, BM-MSCs undergo multiple rounds of purification and multiplication, termed “passages”, which may to alter potency and clinical efficacy. We sought to evaluate the change in cytokine profile during cell expansion.

Methods and Materials

Nine BM-MSC cell lines from 3 human donors underwent an institutional culture expansion protocol. Levels of OA-related cytokines (IL-1β, IL-6, IL-8, IL-10, Stem cell Factor [SCF], Stem Cell Derived Factor-alpha [SDF-α]) were evaluated at three stages of culture expansion: passage 2 (P2), passage 3 (P3), and passage 4 (P4) utilizing Luminex multiplexing technology.

Results

BM-MSC culture expansion altered cytokine profiles in vitro. BM-MSC specific cytokines had defined trends during passage from P2 to P3 and then to P4 (Figure 1). Passage from P2 to P3 demonstrated a decrease in SDF-α, IL-6 and SCF (P<0.05). Although the number of samples evaluated were fewer, the trend continued to be less at P4 (P<0.05). For IL-8 and IL-1β, the transition from P2 to P3 resulted in an increase in cytokine production (P<0.05), but by P4 trended downward.

Conclusion

BM-MSC culture expansion causes changes in OA-relevant cytokines. Further study of the variation in cytokine profile at other stages of BM-MSC preparation (e.g., bone marrow aspirate, P0, P1, through P4) will clarify differences between cytokine profiles of currently used OA therapies, such as bone marrow aspirate concentrate, and expanded BM-MSCs. This study provides initial insights that may guide the process of culture-expansion when using BM-MSCs to treat degenerative joint disease.