High-affinity [3H]PN200-110 and [3H]ryanodine binding to rabbit and frog skeletal muscle

Anderson, Kristin A.; Cohn, A.; Meissner, Gerhard

doi:10.1152/ajpcell.1994.266.2.c462

Cited by 64 publications

(45 citation statements)

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“…The PN200 -110/ryanodine B max ratio is close to 1 in young and adult animals (1-12 months old). This indicates that every fourth foot/RyR1 is linked to a group of four DHPRs, assuming localization at the triadic junction of all DHPRs and RyR1 (21). The B max , K d , and PN200 -110/ryanodine ratio values reported for control mice are similar to the values reported earlier for rabbit muscles (21), fast-twitch rat EDL muscle (25), and Table I. mouse muscles (19).…”

Section: Resultssupporting

confidence: 86%

Overexpression of IGF-1 Exclusively in Skeletal Muscle Prevents Age-related Decline in the Number of Dihydropyridine Receptors

Renganathan¹,

Messi²,

Delbono³

1998

Journal of Biological Chemistry

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Excitation-contraction uncoupling has been identified as a mechanism underlying skeletal muscle weakness in aging mammals (sarcopenia). The basic mechanism for excitation-contraction uncoupling is a larger number of ryanodine receptors (RyR1) uncoupled to dihydropyridine receptors (DHPRs) (Delbono, O., O'Rourke, K. S., and Ettinger, W. H. (1995) J. Membr. Biol. 148, 211-222). In the present study, we used transgenic mice overexpressing human insulin-like growth factor-1 exclusively in skeletal muscle to test the hypothesis that a high concentration of IGF-1 prevents age-related decreases in DHPR number and in muscle force. Transgenic mice express 10 -20-fold higher IGF-1 concentrations than nontransgenic mice at all ages (1-24 months). The number of DHPRs is 50 -100% higher, and the DHPR/RyR1 ratio is 40% higher in transgenic soleus (predominantly type I fiber muscles), extensor digitorum longus (predominantly type II fiber muscles), and the pool of type I and type II fiber muscles than in nontransgenic young (6 months), adult (12 months), and old (24 months) mice. Furthermore, no age-related changes in DHPRs and the DHPR/RyR1 ratio were observed in transgenic muscles. The specific single twitch and tetanic muscle force in old transgenic soleus and extensor digitorum longus muscles are 50% higher than in old nontransgenic muscles. Taken together, these results support the concept that IGF-1-dependent prevention of age-related decline in DHPR expression is associated with stronger muscle contraction in older transgenic mice. Insulin-like growth factor (IGF-1)1 is a trophic factor required for the proliferation of myoblasts, the proliferation of myogenic differentiation, and subsequent growth and hypertrophy of myofibers (1). IGF-1 has been identified as a potent regulator of gene expression in skeletal muscle. Age-related decrease in plasma IGF-1 concentration is well established (2), which may contribute to the decrease in muscle size and strength in the elderly. In addition to effects on muscle development, IGF-1 facilitates skeletal muscle DHPR activity via tyrosine kinase-protein kinase C-dependent phosphorylation (3). Our laboratory has also shown that IGF-1 dependent DHPR modulation is impaired in aging skeletal muscles (4), which may explain, at least partially, the decline in muscle force with aging (5).Specific muscle strength declines with aging in humans and in several animal models of aging (6 -8). The impairment in sustaining the contraction tension during prolonged muscle activation seems to be a general phenomenon in aging mammals. It also becomes apparent from a series of studies on in vitro contractility that the decrease in muscle mass does not explain entirely the age-related decrease in skeletal muscle force (8, 9). Therefore, some other mechanisms are involved in age-dependent loss in muscle strength. Studies done in our laboratory in single human skeletal muscle fiber support the theory that sarcolemmal excitation-sarcoplasmic reticulum Ca 2ϩ release uncoupling (EC uncoupling) is a basic mec...

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Section: Resultssupporting

confidence: 86%

Overexpression of IGF-1 Exclusively in Skeletal Muscle Prevents Age-related Decline in the Number of Dihydropyridine Receptors

Renganathan¹,

Messi²,

Delbono³

1998

Journal of Biological Chemistry

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“…Additionally, there are differences in the molecular make-up of the junction that could determine changes in the control mechanisms. When determined in isolated muscle fractions, ryanodineÏDHP specific binding ratio was 1·02 for rabbits and 1·64 for frogs (Anderson et al 1994), indicating that the ratio of RYRs to DHPRs is greater in amphibian muscle. There are also differences in isoform composition.…”

Section: Discussionmentioning

confidence: 94%

Local calcium release in mammalian skeletal muscle

Shirokova

Garcı́a

Rı́os

1998

The Journal of Physiology

133

155

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Fluo‐3 fluorescence associated with Ca2+ release was recorded with confocal microscopy in single muscle fibres mechanically dissected from fast twitch muscle of rats or frogs, voltage clamped in a two Vaseline‐gap chamber. Interventions that elicited Ca2+ sparks in frog skeletal muscle (low voltage depolarizations, application of caffeine) generated in rat fibres images consistent with substantial release from triadic regions, but devoid of resolvable discrete events. Ca2+ sparks were never observed in adult rat fibres. In contrast, sparks of standard morphology were abundant in myotubes from embryonic mice. Depolarization‐induced gradients of fluorescence between triadic and surrounding regions (which are proportional to Ca2+ release flux) peaked at about 20 ms and then decayed to a steady level. Gradients were greater in frog fibres than in rat fibres. The ratio of peak over steady gradient (R) was steeply voltage dependent in frogs, reaching a maximum of 4.8 at −50 mV (n= 7). In rats, R had an essentially voltage‐independent value of 2.3 (n= 5). Ca2+‐induced Ca2+ release, resulting in concerted opening of several release channels, is thought to underlie Ca2+ sparks and the peak phase of release in frog skeletal muscle. A diffuse ‘small event’ release, similar to that observed in these rats, is also present in frogs and believed to be directly activated by voltage. The present results suggest that in these rat fibres there is little contribution by CICR to Ca2+ release triggered by depolarization, and a lack of concerted channel opening.

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“…SR vesicles were prepared essentially as described (1,45). Briefly, hind-limb muscle from rabbit or mouse was homogenized in buffer containing 20 mM Hepes (pH 7.4), 2 mM EDTA, 0.2 mM EGTA, 0.3 M sucrose, and protease inhibitors (100 nM aprotinin, 20 μM leupeptin, 1 μM pepstatin, 0.2 mM phenylmethylsulfonyl fluoride, 1 mM benzamidine).…”

Section: Methodsmentioning

confidence: 99%

Oxygen-coupled redox regulation of the skeletal muscle ryanodine receptor-Ca ²⁺ release channel by NADPH oxidase 4

Sun

Hess

Nogueira

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

104

109

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Physiological sensing of O 2 tension (partial O 2 pressure, pO 2 ) plays an important role in some mammalian cellular systems, but striated muscle generally is not considered to be among them. Here we describe a molecular mechanism in skeletal muscle that acutely couples changes in pO 2 to altered calcium release through the ryanodine receptor-Ca 2+ -release channel (RyR1). Reactive oxygen species are generated in proportion to pO 2 by NADPH oxidase 4 (Nox4) in the sarcoplasmic reticulum, and the consequent oxidation of a small set of RyR1 cysteine thiols results in increased RyR1 activity and Ca 2+ release in isolated sarcoplasmic reticulum and in cultured myofibers and enhanced contractility of intact muscle. Thus, Nox4 is an O 2 sensor in skeletal muscle, and O 2 -coupled hydrogen peroxide production by Nox4 governs the redox state of regulatory RyR1 thiols and thereby governs muscle performance. These findings reveal a molecular mechanism for O 2 -based signaling by an NADPH oxidase and demonstrate a physiological role for oxidative modification of RyR1.redox signaling | oxygen sensing | S-nitrosylation S pecialized mammalian sensory cells transduce varying O 2 levels, but the mechanisms of O 2 sensing and O 2 -based signaling have not been elucidated fully. In particular, reversible changes in ion channel activity often are implicated in physiological responses to O 2 , but the molecular bases of these changes are unknown. We previously have described an O 2 -sensing and -signaling mechanism in mammalian skeletal muscle that operates on the ryanodine receptor-Ca 2+ -release channel (RyR1), the principal source of Ca 2+ release from the sarcoplasmic reticulum (SR) (1, 2). At relatively low partial pressure of O 2 (pO 2 ), endogenously generated NO regulates RyR1 activity by S-nitrosylation of a single Cys thiol (1, 3). At higher pO 2 , RyR1 activity is enhanced independently of NO in association with the oxidation of a separate, small set of Cys thiols (1). Oxidation of RyR1 thiols at high pO 2 and reduction following transition from high to low pO 2 are observed in isolated SR vesicles (1). However, the molecular mechanisms within the SR that mediate this O 2 -based redox cycle have not been determined. Here we show that the redox enzyme NADPH oxidase 4 (Nox4) is a constituent of the SR and that hydrogen peroxide (H 2 O 2 ) produced by Nox4 in proportion to pO 2 over a physiological range serves as an essential effector of pO 2 -dependent regulation of RyR1 redox status and function. These data demonstrate physiological regulation by reactive oxygen species (ROS) of RyR1 and suggest insights into the molecular mechanisms of O 2 sensing and O 2 -based signaling in mammalian cells. ResultsRyR1 activity in an SR-enriched subcellular fraction (SR vesicles) was enhanced progressively at pO 2 of 1% O 2 , 5% O 2 , and 20% O 2 (ambient pO 2 ) (Fig. 1A); these levels largely recapitulate the physiological muscle O 2 gradient and extend to oxidative stress (4-7). Production of ROS was enhanced similarly, as assessed ...

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High-affinity [3H]PN200-110 and [3H]ryanodine binding to rabbit and frog skeletal muscle

Cited by 64 publications

References 20 publications

Overexpression of IGF-1 Exclusively in Skeletal Muscle Prevents Age-related Decline in the Number of Dihydropyridine Receptors

Overexpression of IGF-1 Exclusively in Skeletal Muscle Prevents Age-related Decline in the Number of Dihydropyridine Receptors

Local calcium release in mammalian skeletal muscle

Oxygen-coupled redox regulation of the skeletal muscle ryanodine receptor-Ca ²⁺ release channel by NADPH oxidase 4

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High-affinity [3H]PN200-110 and [3H]ryanodine binding to rabbit and frog skeletal muscle

Cited by 64 publications

References 20 publications

Overexpression of IGF-1 Exclusively in Skeletal Muscle Prevents Age-related Decline in the Number of Dihydropyridine Receptors

Overexpression of IGF-1 Exclusively in Skeletal Muscle Prevents Age-related Decline in the Number of Dihydropyridine Receptors

Local calcium release in mammalian skeletal muscle

Oxygen-coupled redox regulation of the skeletal muscle ryanodine receptor-Ca 2+ release channel by NADPH oxidase 4

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Oxygen-coupled redox regulation of the skeletal muscle ryanodine receptor-Ca ²⁺ release channel by NADPH oxidase 4