INTRODUCTION: Duchenne muscular dystrophy is caused by the absence of dystrophin. This study aimed to investigate femoral morphological characteristics of lack of dystrophin in MDX mice, considering that this model, different from DMD patient, is not influenced by corticosteroids administration and limited ambulation. MATERIALS AND METHODS: Proximal femur of male 16-week-old Control and MDX mice were submitted to histological, morphometric (volume density of articular cartilage, compact bone, trabecular bone and bone marrow; articular cartilage layers area; articular cartilage cell area), and immunohistochemistry analysis for RUNX-2, RANK-L, MMP-2, MMP-9, Caspase-3 and KI-67. RESULTS: MDX showed loss of linearity of articular cartilage with subchondral bone transition and elevation of this subchondral bone to the articular surface when compared with control. In addition, MDX presented morphological difference in the pantographic network of collagen fibers. Volume density of trabecular bone tissue was higher in the MDX than Control, but volume density of articular cartilage was lower in MDX (p < 0.05). The articular cartilage layers and chondrocytes area were significantly smaller in MDX than Control. These results associated to MMPs and osteogenic markers of proximal femur revealed an adaptation process as a consequence of lack of dystrophin. CONCLUSIONS: The morphological changes observed in the bone tissue of the MDX may be not only secondary to muscle weakness or chronic use of corticosteroids but also our results indicate connections between decrease of cartilage thickness, collagen network alteration and consequent subchondral changes that may lead to articular cartilage degeneration and bone adaptation mechanism in MDX mice.
INTRODUCTION: Duchenne muscular dystrophy is caused by the absence of dystrophin. This study aimed to investigate femoral morphological characteristics of lack of dystrophin in MDX mice, considering that this model, different from DMD patient, is not influenced by corticosteroids administration and limited ambulation. MATERIALS AND METHODS: Proximal femur of male 16-week-old Control and MDX mice were submitted to histological, morphometric (volume density of articular cartilage, compact bone, trabecular bone and bone marrow; articular cartilage layers area; articular cartilage cell area), and immunohistochemistry analysis for RUNX-2, RANK-L, MMP-2, MMP-9, Caspase-3 and KI-67. RESULTS: MDX showed loss of linearity of articular cartilage with subchondral bone transition and elevation of this subchondral bone to the articular surface when compared with control. In addition, MDX presented morphological difference in the pantographic network of collagen fibers. Volume density of trabecular bone tissue was higher in the MDX than Control, but volume density of articular cartilage was lower in MDX (p < 0.05). The articular cartilage layers and chondrocytes area were significantly smaller in MDX than Control. These results associated to MMPs and osteogenic markers of proximal femur revealed an adaptation process as a consequence of lack of dystrophin. CONCLUSIONS: The morphological changes observed in the bone tissue of the MDX may be not only secondary to muscle weakness or chronic use of corticosteroids but also our results indicate connections between decrease of cartilage thickness, collagen network alteration and consequent subchondral changes that may lead to articular cartilage degeneration and bone adaptation mechanism in MDX mice.
Authors: Denise G M McDonald; Maria Kinali; Andrew C Gallagher; Eugenio Mercuri; Francesco Muntoni; Helen Roper; Philip Jardine; David Hilton Jones; M G Pike Journal: Dev Med Child Neurol Date: 2002-10 Impact factor: 5.449
Authors: Jerry R Mendell; Louise R Rodino-Klapac; Zarife Sahenk; Kandice Roush; Loren Bird; Linda P Lowes; Lindsay Alfano; Ann Maria Gomez; Sarah Lewis; Janaiah Kota; Vinod Malik; Kim Shontz; Christopher M Walker; Kevin M Flanigan; Marco Corridore; John R Kean; Hugh D Allen; Chris Shilling; Kathleen R Melia; Peter Sazani; Jay B Saoud; Edward M Kaye Journal: Ann Neurol Date: 2013-09-10 Impact factor: 10.422
Authors: Cuixia Tian; Brenda L Wong; Lindsey Hornung; Jane C Khoury; Lauren Miller; Jean Bange; Irina Rybalsky; Meilan M Rutter Journal: Neuromuscul Disord Date: 2016-08-22 Impact factor: 4.296
Authors: Paul M L Janssen; Jason D Murray; Kevin E Schill; Neha Rastogi; Eric J Schultz; Tam Tran; Subha V Raman; Jill A Rafael-Fortney Journal: PLoS One Date: 2014-02-13 Impact factor: 3.240