Effects of Notch/p38MAPK signaling pathway on articular cartilage defect recovery by BMSCs tissue based on the rabbit articular cartilage defect models

Objective: The objective is to clarify the effects of Notch/p38MAPK signaling pathway on articular cartilage defect recovery by BMSCs tissue and provide a basis for clinical treatments of articular cartilage defects. Methods: A total of 96 healthy male rabbits (weighed 1.5-2.0 kg) that were fully-grown were selected and grouped as the no-treatment group, the model group, and the treatment group in a random manner. Each group included 32 rabbits in total. The no-treatment group was fed without any interventions. The model group and the treatment group were constructed into rabbit knee-joint articular cartilage defect models. In addition, rabbits in the treatment group were given intervention treatments with Notch inhibitor (DAPT) combined with p38MAPK inhibitor (SB203580). The general conditions of rabbits in each group and the conditions of the stained articular cartilage tissue samples were observed, the proliferation of chondrocytes of rabbits in each group was compared. Results: (1) After drug interventions, in contrast to the rabbits in the model group, the general conditions and the chondrocyte recovering situations of rabbits in the treatment group were obviously improved; (2) 8 weeks after model construction, the articular cartilage empty bone lacuna rate of rabbits in the treatment group was (12.13 +/- 1.81)%, which was obviously lower than the synchronous (21.55 +/- 3.07) % articular cartilage empty bone lacuna rate of rabbits in the model group, and there was a statistical significance in the differences (P < 0.05); (3) the absorbance value (OD value) of chondrocytes in the treatment group was (0.34 +/- 0.015), which was obviously higher than the (0.10 +/- 0.020) OD value of chondrocytes in the model group, and there was a statistical significance in the differences (P < 0.05). Conclusion: The inhibition of Notch/p38MAPK signaling pathway can promote the recovery of articular cartilage by BMSCs tissue, accelerate the proliferation of chondrocytes, and contribute to the recovery of knee-joint injuries in rabbits, which provides a reliable basis for clinical treatments of articular cartilage defects. (C) 2019 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.