Differential Effector Response of Amnion- and Adipose-Derived Mesenchymal Stem Cells to Inflammation; Implications for Intradiscal Therapy

Abstract

1Intervertebral disc degeneration (IVDD) is a progressive condition marked by 2 inflammation and tissue destruction. The effector functions of mesenchymal stem cells (MSCs) 3 make them an attractive therapy for patients with IVDD. While several sources of MSCs exist, the 4 optimal choice for use in the inflamed IVD remains a significant question. Adipose (AD)-and 5 amnion (AM)-derived MSCs have several advantages compared to other sources, however, no 6 study has directly compared the impact of IVDD inflammation on their effector functions. Human 7 MSCs were cultured in media with or without supplementation of interleukin-1β and tumor 8 necrosis factor-α at concentrations produced by IVDD cells. MSC proliferation and production of 9 pro-and anti-inflammatory cytokines were quantified following 24-and 48-hours of culture. 10Additionally, the osteogenic and chondrogenic potential of AD-and AM-MSCs was characterized 11 via histology and biochemical analysis following 28 days of culture. In inflammatory culture, AM- 12MSCs produced significantly more anti-inflammatory IL-10 (p=0.004) and larger chondrogenic 13 pellets (p=0.04) with greater percent area staining positively for glycosaminoglycan (p<0.001) 14 compared to AD-MSCs. Conversely, AD-MSCs proliferated more resulting in higher cell numbers 15 (p=0.048) and produced higher concentrations of pro-inflammatory cytokines PGE2 (p=0.030) and 16 IL-1β (p=0.010) compared to AM-MSCs. Additionally, AD-MSCs produced more mineralized 17 matrix (p<0.001) compared to AM-MSCs. These findings begin to inform researchers and 18 clinicians as to which MSC source may be optimal for different IVD therapies including those that 19 may promote regeneration or fusion. Further study is warranted evaluating these cells in systems 20 which recapitulate the nutrient-and oxygen-deprived environment of the degenerate IVD. 21

Extracellular Vesicles Released From Articular Chondrocytes Play a Major Role in Cell–Cell Communication

“…Our data showing that conditioned medium from IL‐1β‐treated chondrocytes after complete removal of EVs and wash out of IL‐1β was still able to reduce the chondrogenic differentiation of C3H10T1/2 cells even though to a lesser degree than EV‐containing medium suggest that articular chondrocytes in an inflammatory state release a variety of factors and cytokines, including but not limited to IL‐6, IL‐8, tumor necrosis factor‐α, and MMPs and EVs that inhibit chondrogenic differentiation. Our findings are consistent with the previous findings showing reduced chondrogenic differentiation of MSCs in the presence of inflammatory cytokines …”

“…Our findings are consistent with the previous findings showing reduced chondrogenic differentiation of MSCs in the presence of inflammatory cytokines. 25,26 JOURNAL OF ORTHOPAEDIC RESEARCH ® APRIL 2020…”

Micro Fragmented Adipose Tissue Promotes the Matrix Synthesis Function of Nucleus Pulposus Cells and Regenerates Degenerated Intervertebral Disc in a Pig Model

“…In addition, MSCs intravenously injected into the lung microenvironment may also induce an inflammatory response by increasing TNF-α and IL-1β 53 . The acidic environment induced the production of proinflammatory cytokines, such as IL-1β and prostaglandin E2 (PGE 2 ), in ADSCs 54 . PGE 2 has a negative impact on IVD cell health and ECM homeostasis even after short-term exposure 55 , 56 .…”

A Momentary Impact Injury of Vertebral Endplates, even without Structural Disruption, Initiates Disc Degeneration In Vitro.

“…The degenerative changes in the IVDs, such as the composition of extracellular matrix (ECM), loss of disc cells, proteoglycans and water content, have been suggested to be the consequence of an upregulation of catabolic matrix metalloproteinases (MMPs) and pro-inflammatory (IL-1β, TNF-α, IL-6) gene transcriptions [22][23][24][25][26]. Consistent with the previous reports, we found that mRNA expressions of catabolic (MMP-9, MMP-13) genes were up-regulated in the impact injury groups, especially at day 14 in the low-impact group.…”