Chondroprotective Effects of Combination Therapy of Acupotomy and Human Adipose Mesenchymal Stem Cells in Knee Osteoarthritis Rabbits via the GSK3β-Cyclin D1-CDK4/CDK6 Signaling Pathway

Abstract

Adipose-derived stem cells (ASCs) are highly chondrogenic and can be used to treat knee osteoarthritis (KOA) by alleviating cartilage defects. Acupotomy, a biomechanical therapy guided by traditional Chinese medicine theory, alleviates cartilage degradation and is widely used in the clinic to treat KOA by correcting abnormal mechanics. However, whether combining acupotomy with ASCs will reverse cartilage degeneration by promoting chondrocyte proliferation in KOA rabbits is unknown. The present study aimed to investigate the effects of combination therapy of acupotomy and ASCs on chondrocyte proliferation and to determine the underlying mechanism in rabbits with KOA induced by knee joint immobilization for 6 weeks. After KOA modeling, five groups of rabbits (acupotomy, ASCs, acupotomy + ASCs, model and control groups) received the indicated intervention for 4 weeks. The combination therapy significantly restored the KOA-induced decrease in passive range of motion (PROM) in the knee joint and reduced the elevated serum level of cartilage oligomeric matrix protein (COMP), a marker for cartilage degeneration. Furthermore, magnetic resonance imaging (MRI) and scanning electron microscopy (SEM) images showed that the combination therapy inhibited cartilage injury. The combination therapy also significantly blocked increases in the mRNA and protein expression of glycogen synthase kinase-3β (GSK3β) and decreases in the mRNA and protein expression of cyclin D1/CDK4 and cyclin D1/CDK6 in cartilage. These findings indicated that the combination therapy mitigated knee joint immobility, promoted chondrocyte proliferation and alleviated cartilage degeneration in KOA rabbits, and these effects may be mediated by specifically regulating the GSK3β-cyclin D1-CDK4/CDK6 pathway.

Acupotomy Contributes to Suppressing Subchondral Bone Resorption in KOA Rabbits by Regulating the OPG/RANKL Signaling Pathway

“…However, whether acupotomy as biomechanical therapy is sufficient to prevent or reverse KOA-induced subchondral bone lesions has not been directly investigated. e biomechanical effects of acupotomy have been confirmed in our preliminary studies [21][22][23][24]. It is well known that muscle dysfunction, characterized by weakened muscle strength and reduced coordination of muscle groups, is a crucial cause of KOA knee mechanical imbalance [37].…”

“…e biomechanical effect of acupotomy is the unique superiority that distinguishes it from other KOA therapies. Preliminary studies [21][22][23][24] have confirmed that acupotomy can prevent cartilage degeneration and delay KOA pathological procession by correcting the abnormal mechanical stress in KOA joints. Is the chondroprotective effect of acupotomy related to the inhibition of KOA subchondral bone resorption?…”

“…It is well known that muscle dysfunction, characterized by weakened muscle strength and reduced coordination of muscle groups, is a crucial cause of KOA knee mechanical imbalance [37]. We chose tendons around the knee as the acupotomy intervention points to correct the abnormal mechanical environment in the knee joint by regulating the mechanical function of muscletendons, followed by effectively activating integrin β1 [22], the crucial mechanical receptor of chondrocytes, and the downstream FAK-PI3K mechanical signaling pathway [21], which inhibited the degradation of the chondrocyte extracellular matrix and promoted chondrocyte proliferation in KOA rabbits [24]. Can this intra-articular benign mechanical load ameliorate KOA subchondral bone lesions through the OPG/RANKL mechanical signaling pathway after acupotomy intervention?…”

“…In previous studies, we found that immobilization of the knee joints of rabbits induced joint rigidity, as measured by passive range of motion (PROM), and the cartilage eroded integrally with extensive bone marrow edema in subchondral bone as observed by MRI [24], accompanied by reduced expression of COL-II and Aggrecan in cartilage [21]. Further, cartilage oligomeric matrix protein (COMP), the biomarker of KOA cartilage degradation, markedly increased in the serum of rabbits [24], which was consistent with the changes in serous COMP observed in KOA patients [39]. In this study, obvious cartilage erosion, significant deletion of Safranin O staining, and subchondral bone destruction were observed after 4 or 6 weeks of immobilization.…”

Effect of Warm Acupuncture Combined with Bone Marrow Mesenchymal Stem Cells Transplantation on Cartilage Tissue in Rabbit Knee Osteoarthritis

“…The rabbit model of cartilage degeneration in KOA was reproduced by plaster immobilization in the right hind limb extension position for 6 weeks [ 25 , 26 ], and the operation is performed as in Figure 1(c) . The rabbit was simply placed in a supine position on the immobilizer, exposing the right knee joint.…”