TY - JOUR
T1 - Lipid accumulation in dysferlin-deficient muscles
AU - Grounds, Miranda
AU - Terrill, Jessica
AU - Radley-Crabb, Hannah
AU - Robertson, T.
AU - Papadimitriou, John
AU - Spuler, S.
AU - Shavlakadze, Tea
PY - 2014
Y1 - 2014
N2 - Dysferlin is a membrane associated protein involved in vesicle trafficking and fusion. Defects in dysferlin result in limb-girdle muscular dystrophy type 2B and Miyoshi myopathy in humans and myopathy in A/Jdys-/- and BLAJ mice, but the pathomechanism of the myopathy is not understood. Oil Red O staining showed many lipid droplets within the psoas and quadriceps muscles of dysferlin-deficient A/Jdys-/- mice aged 8 and 12 months, and lipid droplets were also conspicuous within human myofibers from patients with dysferlinopathy (but not other myopathies). Electron microscopy of 8-month-old A/Jdys-/- psoas muscles confirmed lipid droplets within myofibers and showed disturbed architecture of myofibers. In addition, the presence of many adipocytes was confirmed, and a possible role for dysferlin in adipocytes is suggested. Increased expression of mRNA for a gene involved in early lipogenesis, CCAAT/enhancer binding protein-δ, in 3-month-old A/J dys-/- quadriceps (before marked histopathology is evident), indicates early induction of lipogenesis/adipogenesis within dysferlin-deficient muscles. Similar results were seen for dysferlin-deficient BLAJ mice. These novel observations of conspicuous intermyofibrillar lipid and progressive adipocyte replacement in dysferlin-deficient muscles present a new focus for investigating the mechanisms that result in the progressive decline of muscle function in dysferlinopathies. Copyright © 2014 American Society for Investigative Pathology.
AB - Dysferlin is a membrane associated protein involved in vesicle trafficking and fusion. Defects in dysferlin result in limb-girdle muscular dystrophy type 2B and Miyoshi myopathy in humans and myopathy in A/Jdys-/- and BLAJ mice, but the pathomechanism of the myopathy is not understood. Oil Red O staining showed many lipid droplets within the psoas and quadriceps muscles of dysferlin-deficient A/Jdys-/- mice aged 8 and 12 months, and lipid droplets were also conspicuous within human myofibers from patients with dysferlinopathy (but not other myopathies). Electron microscopy of 8-month-old A/Jdys-/- psoas muscles confirmed lipid droplets within myofibers and showed disturbed architecture of myofibers. In addition, the presence of many adipocytes was confirmed, and a possible role for dysferlin in adipocytes is suggested. Increased expression of mRNA for a gene involved in early lipogenesis, CCAAT/enhancer binding protein-δ, in 3-month-old A/J dys-/- quadriceps (before marked histopathology is evident), indicates early induction of lipogenesis/adipogenesis within dysferlin-deficient muscles. Similar results were seen for dysferlin-deficient BLAJ mice. These novel observations of conspicuous intermyofibrillar lipid and progressive adipocyte replacement in dysferlin-deficient muscles present a new focus for investigating the mechanisms that result in the progressive decline of muscle function in dysferlinopathies. Copyright © 2014 American Society for Investigative Pathology.
U2 - 10.1016/j.ajpath.2014.02.005
DO - 10.1016/j.ajpath.2014.02.005
M3 - Article
C2 - 24685690
SN - 0002-9440
VL - 184
SP - 1668
EP - 1676
JO - American Journal of Pathology
JF - American Journal of Pathology
IS - 6
ER -