Browsing by Subject "Muscular dystrophy"

Now showing 1 - 3 of 3
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    Comparative study of calcium and calcium-related enzymes with differentiation markers in different ages and muscle types in mdx mice.
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Gaglianone, Rhayanna B.; Bloise, Flavia Fonseca; Carvalho, Tania Maria Ortiga; Santos, Thereza Quirico; Costa, Manoel Luis; Mermelstein, Claudia
    Sarcolemma instability and increased calcium influx in muscle fibers are characteristics of the Duchenne muscular dystrophy. Excessive calcium activates calcium-dependent enzymes, such as calpains (CAPN) and matrix metalloproteases (MMP). Here, we analyzed calcium deposits, the activity of CAPN and MMP and the expression of Myh, SERCA and myogenic regulatory factors in different skeletal muscles during myonecrosis (4-weeks) and regeneration (12-weeks) phases of the mdx muscular pathology. Alizarin red staining was used to assess calcium deposits, casein and gelatin zymography were performed to evaluate CAPN and MMP activity, and qPCR was used to evaluate the expression of Myh, Capn, Atp2a1 and Atp2a2, Myod1 and Myog. We observed the following characteristics in mdx muscles: (i) calcium deposits almost exclusively in mdx muscles, (ii) lower CAPN1 activity in mdx muscles, (iii) higher CAPN2 activity in mdx muscles (only at 12 wks), (iv) autolyzed CAPN activity exclusively in mdx muscles, (v) lower expression of Capn1 and higher expression of Capn2 in mdx muscles; (vi) lower expression of Atp2a1 and Atp2a2 in mdx muscles, (vii) higher MMP (pre pro MMP2, pro MMP2, MMP2 and MMP9) activity in mdx muscles, (viii) MMP2 activity exclusively in mdx muscles at 12 wks, (ix) MMP9 activity exclusively in mdx muscles, (x) higher expression of Myog in mdx muscles at 12 wks, and (xi) lower expression of Myh (Myh7, Myh2, Myh1, Myh4) in mdx muscles, particularly Myh7 and Myh2. The collection of our results provides valuable information for a better characterization of mdx pathology phenotype
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    Persistent mdx diaphragm alterations are accompanied by increased expression and activity of calcium and muscle-specific proteins
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2021) Gaglianone, Rhayanna B.; Fonseca Bloise, Flavia; Lagrota-Candido, Jussara; Mermelstein, Claudia; Quirico-Santos, Thereza
    The mdx mouse model of Duchenne Muscular Dystrophy (DMD) presents sarcolemma instability and develops a mild multi-stage dystrophinopathy characterized by intense myonecrosis with inflammatory infiltrate at 4-weeks; muscular regeneration at 12-weeks and persistent fibrosis onwards. Mdx diaphragm muscle has a more severe phenotype with structural and functional deterioration that closely resembles the diaphragm impairment responsible for DMD human patients' morbidity. Herein, we compared calcium deposits, activity of calciumrelated proteases, and expression of muscle-specific proteins in mdx diaphragm at 4-weeks and 12-weeks. We found increased calcium deposits mainly at 12- weeks, concomitant with high activity of calpains and matrix metalloprotease-9, but decreased expression of Myh4 (Myhc IIb) and Atp2a1 (SERCA1), and high expression of the myogenic regulatory factors Myod1 and Myog. Our results suggest that increased calcium deposits and persistent activity of calcium dependent proteases throughout the disease are involved in the degeneration and regeneration processes in the mdx diaphragm.
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    Reduced expression of sarcospan in muscles of Fukuyama congenital muscular dystrophy
    (Murcia : F. Hernández, 2008) Yoshihiro Wakayama; Masahiko Inoue; Hiroko Kojima; Sumimasa Yamashita; Seiji Shibuya; Takahiro Jimi; Hajime Hara; Yoko Matsuzaki; Hiroaki Oniki; Motoi Kanagawa; Kazuhiro Kobayashi; Tatsushi Toda
    Summary. Expression profiles of sarcospan in muscles with muscular dystrophies are scarcely reported. To examine this, we studied five Fukuyama congenital muscular dystrophy (FCMD) muscles, five Duchenne muscular dystrophy (DMD) muscles, five disease control and five normal control muscles. Immunoblot showed reactions of sarcospan markedly decreased in FCMD and DMD muscle extracts. Immunohistochemistry of FCMD muscles showed that most large diameter myofibers expressed sarcospan discontinuously at their surface membranes. Immature small diameter FCMD myofibers usually did not express sarcospan. Immunoreactivity of sarcospan in DMD muscles was similarly reduced. With regard to dystroglycans and sarcoglycans, immunohistochemistry of FCMD muscles showed selective deficiency of glycosylated α- dystroglycan, together with reduced expression of ß- dystroglycan and α-, ß-, γ-, δ-sarcoglycans. Although the expression of glycosylated α-dystroglycan was lost, scattered FCMD myofibers showed positive immunoreaction with an antibody against the core protein of α-dystroglycan. The group mean ratios of sarcospan mRNA copy number versus GAPDH mRNA copy number by real-time RT-PCR showed that the ratios between FCMD and normal control groups were not significantly different (P>0.1 by the two-tailed t test). This study implied either O-linked glycosylation defects of α-dystroglycan in the Golgi apparatus of FCMD muscles may lead to decreased expression of sarcoglycan and sarcospan molecules, or selective deficiency of glycosylated α-dystroglycan due to impaired glycosylation in FCMD muscles may affect the molecular integrity of the basal lamina of myofibers. This, in turn, leads to decreased expression of sarcoglycans, and finally of sarcospan at the FCMD myofiber surfaces.