Core D will perform the qualitative and quantitative histological and ultrastructural checks that are necessary to support all other Projects. The Core will not only supply various techniques of electron, phase contrast and confocal microscopy, but it will also operate at a high standard of quality and offer an expert critical evaluation of the results of experimental and molecular alterations. The uniform and consistent use of high quality images will allow the detection of even subtle alterations in protein-protein interactions and in the response of individual cell organelles that either are at the basis of altered functions or are the long term results of such alterations. It is clear that the overall ultrastructural response of the muscle fiber to mutations affecting excitation-contraction coupling are quite specific and offer considerable insight into causative effects. In the past period we have evidenced a strong fiber type- and gender-dependence of the pathology, that correspindes quite well with similar variations in function. Two general approaches are proposed. One is to define any alterations in the relationships between the major protein components of calcium release units (CRUs, triads in skeletal muscle) within the context of the mutation and the other is to follow the development of pathology (most specifically mitochondrial, myofibrillar and CRUs'alterations) through development and aging and in relation to the known functional effects of the mutation on CRUs'channels.This will be achieved by combining light microscope techniques (phase contrast of fibers whole mounts and confocal imaging of fluorescently immunolabeled fibers) with thin sectioning and freeze-fracture for electron microscopy supplemented by quantitative morphometry techniques. The core aims at defining the primary impact of each mutation on the macromelcular assembly of calcium release units within a short term and the secondary impact on SR, mitochondria and contractile material on the long term.
To understand the muscle pathology of MH susceptible individuals it will be crucial to detect if any subtle alterations in the relationship between key component of the calcium release units machinery (mostly DHPR and RyR) underlie the RyR function imbalance. To that effect, ultrastructure will be tested by different technical approaches at an early and a late age.
|Lavorato, Manuela; Iyer, V Ramesh; Dewight, Williams et al. (2017) Increased mitochondrial nanotunneling activity, induced by calcium imbalance, affects intermitochondrial matrix exchanges. Proc Natl Acad Sci U S A 114:E849-E858|
|Holland, Erika B; Goldstone, Jared V; Pessah, Isaac N et al. (2017) Ryanodine receptor and FK506 binding protein 1 in the Atlantic killifish (Fundulus heteroclitus): A phylogenetic and population-based comparison. Aquat Toxicol 192:105-115|
|Zhang, Rui; Pessah, Isaac N (2017) Divergent Mechanisms Leading to Signaling Dysfunction in Embryonic Muscle by Bisphenol A and Tetrabromobisphenol A. Mol Pharmacol 91:428-436|
|Perni, Stefano; Lavorato, Manuela; Beam, Kurt G (2017) De novo reconstitution reveals the proteins required for skeletal muscle voltage-induced Ca2+ release. Proc Natl Acad Sci U S A 114:13822-13827|
|Linsley, Jeremy W; Hsu, I-Uen; Groom, Linda et al. (2017) Congenital myopathy results from misregulation of a muscle Ca2+ channel by mutant Stac3. Proc Natl Acad Sci U S A 114:E228-E236|
|Lavorato, Manuela; Gupta, Pawan K; Hopkins, Philip M et al. (2016) Skeletal Muscle Microalterations in Patients Carrying Malignant Hyperthermia-Related Mutations of the e-c Coupling Machinery. Eur J Transl Myol 26:6105|
|Ronjat, Michel; Feng, Wei; Dardevet, Lucie et al. (2016) In cellulo phosphorylation induces pharmacological reprogramming of maurocalcin, a cell-penetrating venom peptide. Proc Natl Acad Sci U S A 113:E2460-8|
|Franzini-Armstrong, Clara (2016) Can the Arrangement of RyR2 in Cardiac Muscle Be Predicted? Biophys J 110:2563-5|
|Hopkins, Philip M; Fiszer, Dorota; Shaw, Marie-Anne et al. (2016) In Reply. Anesthesiology 124:511|
|Polster, Alexander; Nelson, Benjamin R; Olson, Eric N et al. (2016) Stac3 has a direct role in skeletal muscle-type excitation-contraction coupling that is disrupted by a myopathy-causing mutation. Proc Natl Acad Sci U S A 113:10986-91|
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