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Effect of Plasminogen Activator Inhibitor-1 on extracellular matrix homeostasis in scaffold-free spheroids from human
Carlos Suarez-Ahedo1, Carlos Martinez-Armenta2, Laura E Martínez-Gómez2
1National Rehabilitation Institute of Mexico, Geroscience Laboratory, Mexico City, Mexico; National Rehabilitation Institute of Mexico, Adult Hip and Knee Reconstruction Department, Mexico City, Mexico; American Hip Institute, Chicago, IL, USA.
Introduction:
New trends in osteoarthritis research focus on the use of biological therapy; in this context, the use of Plasminogen Activator Inhibitor-1 (PAI-1) is considered a potential therapeutic strategy to prevent extracellular matrix (ECM) degradation in osteoarthritis (OA) management. However, in vitro studies have not demonstrated its effect on the expression of ECM homeostasis-related genes.
Methods:
Human OA cartilage-derived chondrocytes were used to generate scaffold-free spheroids under hypoxia conditions. The spheroids were exposed to PAI-1 for 24h, and cell viability was measured. Then qRT-PCR was used to analyze the expression of ECM components and degradative enzymes, including COL2A1, SOX9, ACAN, COL1A1, MMP3, MMP9, MMP13, ADAMTS4, ADAMTS5, TIMP1, TIMP2, TIMP3, uPA and tPA.
Results:
PAI-1 treatment consistently maintained cell viability and chondrocyte spheroid integrity. At the 50ng/mL concentration, PAI-1 increased the gene expression of COL2A1 and reduced SOX9, ACAN, MMP3, MMP9, TIMP2, and tPA. Moreover, the functional COL2A1/COL1A1 ratio was significantly increased in PAI-1-treated spheroids.
Conclusion:
Our results suggest that PAI-1 treatment exerts a complex and multifaceted influence on spheroids' ECM. While it supports matrix integrity by reducing the gene expression of ECM remodeling enzymes, such as MMPs and ADAMTS5, it also induces unfavorable changes in chondrogenesis-related marker genes, such as SOX9 and ACAN. These findings indicate that the cellular response to PAI-1 is not unidirectional, warranting further investigation to understand its precise biological implications.
Insights
Plasminogen Activator Inhibitor-1 (PAI-1) shows complex effects on osteoarthritis cartilage spheroids. While PAI-1 supports matrix integrity by reducing ECM remodeling enzymes, it negatively impacts chondrogenesis markers, requiring further study.
Area of Science:
- Biomedical research
- Osteoarthritis (OA) pathogenesis
- Extracellular matrix (ECM) biology
Background:
- Osteoarthritis (OA) research explores biological therapies to prevent extracellular matrix (ECM) degradation.
- Plasminogen Activator Inhibitor-1 (PAI-1) is investigated as a potential therapeutic agent for OA.
- Previous in vitro studies lacked data on PAI-1's effect on ECM homeostasis genes.
Observation:
- Human OA chondrocytes formed scaffold-free spheroids under hypoxia.
- Spheroids were treated with PAI-1 (50ng/mL) for 24 hours.
- Gene expression of ECM components, degradative enzymes, and inhibitors was analyzed via qRT-PCR.
Findings:
- PAI-1 maintained chondrocyte viability and spheroid integrity.
- PAI-1 increased COL2A1 expression and decreased SOX9, ACAN, MMP3, MMP9, TIMP2, and tPA gene expression.
- The COL2A1/COL1A1 ratio, indicative of functional matrix, was significantly elevated.
Implications:
- PAI-1 exhibits a dual effect on OA cartilage spheroids.
- It reduces expression of ECM-degrading enzymes (MMPs, ADAMTS5) but also downregulates chondrogenesis markers (SOX9, ACAN).
- Further research is needed to clarify PAI-1's complex biological role in OA treatment.
