The Effect of Exercise on the Early Stages of Mesenchymal Stromal Cell-Induced Cartilage Repair in a Rat Osteochondral Defect Model

The repair of articular cartilage is challenging owing to the restriction in the ability of articular cartilage to repair itself. Therefore, cell supplementation therapy is possible cartilage repair method. However, few studies have verified the efficacy and safety of cell supplementation therapy. The current study assessed the effect of exercise on early the phase of cartilage repair following cell supplementation utilizing mesenchymal stromal cell (MSC) intra-articular injection. An osteochondral defect was created on the femoral grooves bilaterally of Wistar rats. Mesenchymal stromal cells that were obtained from male Wistar rats were cultured in monolayer. After 4 weeks, MSCs were injected into the right knee joint and the rats were randomized into an exercise or no-exercise intervention group. The femurs were divided as follows: C group (no exercise without MSC injection); E group (exercise without MSC injection); M group (no exercise with MSC injection); and ME group (exercise with MSC injection). At 2, 4, and 8 weeks after the injection, the femurs were sectioned and histologically graded using the Wakitani cartilage repair scoring system. At 2 weeks after the injection, the total histological scores of the M and ME groups improved significantly compared with those of the C group. Four weeks after the injection, the scores of both the M and ME groups improved significantly. Additionally, the scores in the ME group showed a significant improvement compared to those in the M group. The improvement in the scores of the E, M, and ME groups at 8 weeks were not significantly different. The findings indicate that exercise may enhance cartilage repair after an MSC intra-articular injection. This study highlights the importance of exercise following cell transplantation therapy

ヒト変形性膝関節症に伴う軟骨下骨変性を捉える超音波指標：マイクロCTパラメータとの対比によるEx Vivo研究

京都大学0048新制・課程博士博士(人間健康科学)甲第21460号人健博第67号新制||人健||5(附属図書館)京都大学大学院医学研究科人間健康科学系専攻(主査)教授 杉本 直三, 教授 藤井 康友, 教授 松田 秀一学位規則第4条第1項該当Doctor of Human Health SciencesKyoto UniversityDFA

Three-dimensional motion analysis for comprehensive understanding of gait characteristics after sciatic nerve lesion in rodents

Rodent models of sciatic nerve lesion are regularly used to assess functional deficits in nerves. Impaired locomotor functions induced by sciatic nerve lesion are currently evaluated with scoring systems despite their limitations. To overcome these shortcomings, which includes low sensitivity, little significance, and the representation of only marginal components of motion profiles, some additional metrics have been introduced. However, a quantitative determination of motion deficits is yet to be established. We used a three-dimensional motion analysis to investigate gait deficits after sciatic nerve lesion in rats. This enabled us to depict the distorted gait motion using both traditional parameters and novel readouts that are specific for the three-dimensional analysis. Our results suggest that three-dimensional motion analysis facilitates a comprehensive understanding of the gait impairment specifically, but not limited to, a sciatic lesion rat model. A broad application of these methods will improve understanding and standardized motor assessment

Histological images at 4 weeks.

<p>Macroscopic image and microscopic images of regenerated cartilage at 4 weeks. A: C group (Control); B: E group (exercise without MSC); C: M group (no exercise with MSC injection); D: ME group (exercise with MSC injection). a: macroscopic image. The arrow heads pointed edges of the defect; b: stained with hematoxylin and eosin (HE; ×200); c: stained with HE (×400); d: stained with safranin-O/fast green (×200); e: type II collagen immunohistochemically stained image (×100); f: type I collagen immunohistochemically stained image (×100). The arrow heads in b, d-f denote the border between the defect area and host cartilage. Black bars represent 0.1 mm.</p

Results of 5 parameter and total score in Wakitani score in 2, 4, and 8 weeks.

<p>Displacement values were given as median (interquartile). MSC: mesenchymal stromal cell, C: control group, E group: exercise group, M group: MSC injection group, ME group: exercise with MSC injection group. n = 8, (vs. C: *; <i>P</i> < 0.05, **; <i>P</i> < 0.01, vs. E: †; <i>P</i> < 0.05, ‡; <i>P</i> < 0.01, vs. M: §; <i>P</i> < 0.05).</p

Microscopic-stained images of normal and defective cartilage.

<p>a–d: Normal cartilage. a: Stained with hematoxylin and eosin (HE; × 400); b: Stained with safranin-O/fast green (SO; ×200); c: Type II collagen immunohistochemically stained image (×100); d: Type I collagen immunohistochemically stained image (×100). Hyaline cartilage cell morphology resembling a round shaped cell was observed. Cartilage 4 weeks after the creation of an osteochondral defect. e: Stained with hematoxylin and eosin (HE; × 400); f: Stained with safranin-O/fast green (SO; ×200); g: Type II collagen immunohistochemically stained image (×100); h: Type I collagen immunohistochemically stained image (×100). Fibroblastic cell morphology resembling a spindle shaped cell was observed. Black bars represent 0.1 mm. Arrowheads denote the border between the defect area and host cartilage.</p

Quantitative evaluation for area% of type II collagen IHC staining.

<p>a: At 2 weeks, b: At 4 weeks, c: At 8 weeks. Boxplots display the median and interquartile range, n = 8/group, (*<i>P</i> < 0.05, **; <i>P</i> < 0.01).</p

Histological images at 8 weeks.

<p>Macroscopic and microscopic images of regenerated cartilage at 8 weeks. A: C group (Control); B: E group (exercise without MSC); C: M group (no exercise with MSC injection); D: ME group (exercise with MSC injection). a: macroscopic image. The arrow heads pointed edges of the defect; b: stained with hematoxylin and eosin (HE; ×200); c: stained with HE (×400); d: stained with safranin-O/fast green (×200); e: type II collagen immunohistochemically stained image (×100); f: type I collagen immunohistochemically stained image (×100). The arrow heads in b, d-f denote the border between the defect area and host cartilage. Black bars represent 0.1 mm.</p