Obscurin-Dependent Localization of Ankyrin B is required for the Organization of Sub-Sarcolemma Microtubules, Localization of Dystrophin, and Sarcolemmal Integrity in Skeletal Muscle

We recently reported that skeletal muscle fibers of obscurin knockout (KO) mice present altered distribution of ankyrin B (ankB), disorganization of the subsarcolemmal microtubules, and reduced localization of dystrophin at costameres. In addition, these mice have impaired running endurance and increased exercise-induced sarcolemmal damage compared with wild-type animals. Here, we report results from a combined approach of physiological, morphological, and structural studies in which we further characterize the skeletal muscles of obscurin KO mice. A detailed examination of exercise performance, using different running protocols, revealed that the reduced endurance of obscurin KO animals on the treadmill depends on exercise intensity and age. Indeed, a mild running protocol did not evidence significant differences between control and obscurin KO mice, whereas comparison of running abilities of 2-, 6-, and 11-mo-old mice exercised at exhaustion revealed a progressive age-dependent reduction of the exercise tolerance in KO mice. Histological analysis indicated that heavy exercise induced leukocyte infiltration, fibrotic connective tissue deposition, and hypercontractures in the diaphragm of KO mice. On the same line, electron microscopy revealed that, in the diaphragm of exercised obscurin KO mice, but not in the hindlimb muscles, both M-line and H-zone of sarcomeres appeared wavy and less defined. Altogether, these results suggest that obscurin is required for the maintenance of morphological and ultrastructural integrity of skeletal muscle fibers against damage induced by intense mechanical stress and point to the diaphragm as the skeletal muscle most severely affected in obscurin-deficient mice.

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PERM1 interacts with the MICOS-MIB complex to connect the mitochondria and sarcolemma via ankyrin B

Nature Communications ◽

10.1038/s41467-021-25185-3 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Theresa Bock ◽

Clara Türk ◽

Sriram Aravamudhan ◽

Lena Keufgens ◽

Wilhelm Bloch ◽

...

Keyword(s):

Skeletal Muscle ◽

Mitochondrial Membrane ◽

Muscle Force ◽

Transmembrane Helix ◽

Adaptor Protein ◽

Interaction Study ◽

Peripheral Areas ◽

Subsarcolemmal Mitochondria ◽

Complex I Activity ◽

Ankyrin B

AbstractSkeletal muscle subsarcolemmal mitochondria (SSM) and intermyofibrillar mitochondria subpopulations have distinct metabolic activity and sensitivity, though the mechanisms that localize SSM to peripheral areas of muscle fibers are poorly understood. A protein interaction study and complexome profiling identifies PERM1 interacts with the MICOS-MIB complex. Ablation of Perm1 in mice reduces muscle force, decreases mitochondrial membrane potential and complex I activity, and reduces the numbers of SSM in skeletal muscle. We demonstrate PERM1 interacts with the intracellular adaptor protein ankyrin B (ANKB) that connects the cytoskeleton to the plasma membrane. Moreover, we identify a C-terminal transmembrane helix that anchors PERM1 into the outer mitochondrial membrane. We conclude PERM1 functions in the MICOS-MIB complex and acts as an adapter to connect the mitochondria with the sarcolemma via ANKB.

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Absence of Major Side Effects of Nifedipine Following Treatment of Duchenne Dystrophy

PEDIATRICS ◽

10.1542/peds.75.6.1168 ◽

1985 ◽

Vol 75 (6) ◽

pp. 1168-1169

Author(s):

RICHARD T. MOXLEY

Keyword(s):

Skeletal Muscle ◽

Duchenne Muscular Dystrophy ◽

Muscular Dystrophy ◽

Functional Ability ◽

Laboratory Data ◽

Blocking Agent ◽

Duchenne Dystrophy ◽

Double Blind ◽

Channel Blocking ◽

Sarcolemmal Integrity

Abnormal calcium accumulation in skeletal muscle due to altered sarcolemmal integrity may be important in the pathogenesis of Duchenne muscular dystrophy. To evaluate the potential beneficial effect of a calcium channel-blocking agent on the course of Duchenne muscular dystrophy, 105 patients were randomly selected for a double-blind 18-month study utilizing treatment with nifedipine (n = 54) or placebo (n = 51). Muscle strength, contractures, functional ability, cardiopulmonary changes, and laboratory data were monithred; the detailed results are published elsewhere.

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Ankyrin-B Interactions with Spectrin and Dynactin-4 Are Required for Dystrophin-based Protection of Skeletal Muscle from Exercise Injury

Journal of Biological Chemistry ◽

10.1074/jbc.m110.187831 ◽

2010 ◽

Vol 286 (9) ◽

pp. 7370-7378 ◽

Cited By ~ 33

Author(s):

Gai Ayalon ◽

Janell D. Hostettler ◽

Jan Hoffman ◽

Krishnakumar Kizhatil ◽

Jonathan Q. Davis ◽

...

Keyword(s):

Skeletal Muscle ◽

Ankyrin B

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1189-P: Ankyrin-B Modulates the Integrity and Bioenergetic Capacity of Skeletal Muscle Fibers

Diabetes ◽

10.2337/db21-1189-p ◽

2021 ◽

Vol 70 (Supplement 1) ◽

pp. 1189-P

Author(s):

KAYLEIGH VOOS ◽

JOYCE TZENG ◽

DAMARIS LORENZO

Keyword(s):

Skeletal Muscle ◽

Muscle Fibers ◽

Skeletal Muscle Fibers ◽

Ankyrin B

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Pharmacological activation of PPAR / stimulates utrophin A expression in skeletal muscle fibers and restores sarcolemmal integrity in mature mdx mice

Human Molecular Genetics ◽

10.1093/hmg/ddp431 ◽

2009 ◽

Vol 18 (23) ◽

pp. 4640-4649 ◽

Cited By ~ 70

Author(s):

P. Miura ◽

J. V. Chakkalakal ◽

L. Boudreault ◽

G. Belanger ◽

R. L. Hebert ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Fibers ◽

Mdx Mice ◽

Skeletal Muscle Fibers ◽

Sarcolemmal Integrity

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Ankyrin-B Is Required for Intracellular Sorting of Structurally Diverse Ca2+ Homeostasis Proteins

The Journal of Cell Biology ◽

10.1083/jcb.147.5.995 ◽

1999 ◽

Vol 147 (5) ◽

pp. 995-1008 ◽

Cited By ~ 84

Author(s):

Shmuel Tuvia ◽

Mona Buhusi ◽

Lydia Davis ◽

Mary Reedy ◽

Vann Bennett

Keyword(s):

Skeletal Muscle ◽

Plasma Membrane ◽

Ryanodine Receptor ◽

Striated Muscle ◽

Intracellular Localization ◽

Ryanodine Receptors ◽

Ip3 Receptors ◽

B Mice ◽

Intracellular Sorting ◽

Ankyrin B

This report describes a congenital myopathy and major loss of thymic lymphocytes in ankyrin-B (−/−) mice as well as dramatic alterations in intracellular localization of key components of the Ca2+ homeostasis machinery in ankyrin-B (−/−) striated muscle and thymus. The sacoplasmic reticulum (SR) and SR/T-tubule junctions are apparently preserved in a normal distribution in ankyrin-B (−/−) skeletal muscle based on electron microscopy and the presence of a normal pattern of triadin and dihydropyridine receptor. Therefore, the abnormal localization of SR/ER Ca ATPase (SERCA) and ryanodine receptors represents a defect in intracellular sorting of these proteins in skeletal muscle. Extrapolation of these observations suggests defective targeting as the basis for abnormal localization of ryanodine receptors, IP3 receptors and SERCA in heart, and of IP3 receptors in the thymus of ankyrin-B (−/−) mice. Mis-sorting of SERCA 2 and ryanodine receptor 2 in ankyrin-B (−/−) cardiomyocytes is rescued by expression of 220-kD ankyrin-B, demonstrating that lack of the 220-kD ankyrin-B polypeptide is the primary defect in these cells. Ankyrin-B is associated with intracellular vesicles, but is not colocalized with the bulk of SERCA 1 or ryanodine receptor type 1 in skeletal muscle. These data provide the first evidence of a physiological requirement for ankyrin-B in intracellular targeting of the calcium homeostasis machinery of striated muscle and immune system, and moreover, support a catalytic role that does not involve permanent stoichiometric complexes between ankyrin-B and targeted proteins. Ankyrin-B is a member of a family of adapter proteins implicated in restriction of diverse proteins to specialized plasma membrane domains. Similar mechanisms involving ankyrins may be essential for segregation of functionally defined proteins within specialized regions of the plasma membrane and within the Ca2+ homeostasis compartment of the ER.

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Double-blind study of metaxalone; use as skeletal-muscle relaxant

JAMA ◽

10.1001/jama.195.6.479 ◽

1966 ◽

Vol 195 (6) ◽

pp. 479-480 ◽

Cited By ~ 3

Author(s):

S. Diamond

Keyword(s):

Skeletal Muscle ◽

Muscle Relaxant ◽

Blind Study ◽

Double Blind Study ◽

Double Blind ◽

Skeletal Muscle Relaxant

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Endotoxin Alteration of the Mucopolysaccharide Blood Vessel Coating in Rats

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050755 ◽

1974 ◽

Vol 32 ◽

pp. 148-149

Author(s):

D. E. Philpott ◽

A. Takahashi

Keyword(s):

Skeletal Muscle ◽

Endothelial Cells ◽

Salivary Gland ◽

Carotid Artery ◽

Basement Membrane ◽

Coronary Vessels ◽

Ruthenium Red ◽

E Coli ◽

Old Rats ◽

The Brain

Two month, eight month and two year old rats were treated with 10 or 20 mg/kg of E. Coli endotoxin I. P. The eight month old rats proved most resistant to the endotoxin. During fixation the aorta, carotid artery, basil arartery of the brain, coronary vessels of the heart, inner surfaces of the heart chambers, heart and skeletal muscle, lung, liver, kidney, spleen, brain, retina, trachae, intestine, salivary gland, adrenal gland and gingiva were treated with ruthenium red or alcian blue to preserve the mucopolysaccharide (MPS) coating. Five, 8 and 24 hrs of endotoxin treatment produced increasingly marked capillary damage, disappearance of the MPS coating, edema, destruction of endothelial cells and damage to the basement membrane in the liver, kidney and lung.

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Ultra-Rapid Freezing of Isolated Skeletal Muscle Fibers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100080316 ◽

1977 ◽

Vol 35 ◽

pp. 576-577

Author(s):

Joachim R. Sommer ◽

Nancy R. Wallace

Keyword(s):

Skeletal Muscle ◽

Sarcoplasmic Reticulum ◽

Granular Material ◽

Nuclear Envelope ◽

Intracellular Calcium ◽

Ruthenium Red ◽

Threshold Concentration ◽

Rapid Freezing ◽

Frog Skeletal Muscle ◽

Electrical Isolation

After Howell (1) had shown that ruthenium red treatment of fixed frog skeletal muscle caused collapse of the intermediate cisternae of the sarcoplasmic reticulum (SR), forming a pentalaminate structure by obi iterating the SR lumen, we demonstrated that the phenomenon involves the entire SR including the nuclear envelope and that it also occurs after treatment with other cations, including calcium (2,3,4).From these observations we have formulated a hypothesis which states that intracellular calcium taken up by the SR at the end of contraction causes the M rete to collapse at a certain threshold concentration as the first step in a subsequent centrifugal zippering of the free SR toward the junctional SR (JSR). This would cause a) bulk transport of SR contents, such as calcium and granular material (4) into the JSR and, b) electrical isolation of the free SR from the JSR.

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