Effects of Hypoxic Adipose-Derived Mesenchymal Stem Cells and Their Secretome on Type II Collagen Expression in a Rabbit Model of Disc Degeneration

Abstract

Introduction: Intervertebral disc (IVD) degeneration is a major cause of low back pain, and is characterized by the loss of extracellular matrix, particularly type II collagen. Regenerative therapies using mesenchymal stem cells (MSCs) and their secretome have shown promise, but their comparative effects on type II collagen expression require further investigation. This study aimed to evaluate and compare the effects of allogeneic hypoxic adipose-derived mesenchymal stem cells (Ad-MSCs) and their secretome on type II collagen expression in a rabbit model of IVD degeneration. Methods: A true experimental study was conducted on 18 New Zealand White rabbits. Degeneration was induced by needle puncture. Subjects were divided into three groups: control (fibrin glue), P1 (hypoxic Ad-MSC), and P2 (secretome). After 8 weeks, type II collagen expression was analyzed using immunohistochemistry. Results: Both P1 and P2 showed significantly higher type II collagen expression than the control (p = 0.001 and p < 0.001, respectively). The secretome group (P2) showed significantly higher expression than the Ad-MSC group (P1) (p = 0.039). These findings suggest that the secretome may provide a greater stimulatory effect on type II collagen expression than direct cell administration. Conclusion: The hypoxic Ad-MSC-derived secretome resulted in higher type II collagen expression than hypoxic Ad-MSCs administration in this rabbit model.