Skip to Content
Merck
  • Skeletal muscle expression of the adhesion-GPCR CD97: CD97 deletion induces an abnormal structure of the sarcoplasmatic reticulum but does not impair skeletal muscle function.

Skeletal muscle expression of the adhesion-GPCR CD97: CD97 deletion induces an abnormal structure of the sarcoplasmatic reticulum but does not impair skeletal muscle function.

PloS one (2014-06-21)
Tatiana Zyryanova, Rick Schneider, Volker Adams, Doreen Sittig, Christiane Kerner, Claudia Gebhardt, Henrik Ruffert, Stefan Glasmacher, Pierre Hepp, Karla Punkt, Jochen Neuhaus, Jörg Hamann, Gabriela Aust
ABSTRACT

CD97 is a widely expressed adhesion class G-protein-coupled receptor (aGPCR). Here, we investigated the presence of CD97 in normal and malignant human skeletal muscle as well as the ultrastructural and functional consequences of CD97 deficiency in mice. In normal human skeletal muscle, CD97 was expressed at the peripheral sarcolemma of all myofibers, as revealed by immunostaining of tissue sections and surface labeling of single myocytes using flow cytometry. In muscle cross-sections, an intracellular polygonal, honeycomb-like CD97-staining pattern, typical for molecules located in the T-tubule or sarcoplasmatic reticulum (SR), was additionally found. CD97 co-localized with SR Ca2+-ATPase (SERCA), a constituent of the longitudinal SR, but not with the receptors for dihydropyridine (DHPR) or ryanodine (RYR), located in the T-tubule and terminal SR, respectively. Intracellular expression of CD97 was higher in slow-twitch compared to most fast-twitch myofibers. In rhabdomyosarcomas, CD97 was strongly upregulated and in part more N-glycosylated compared to normal skeletal muscle. All tumors were strongly CD97-positive, independent of the underlying histological subtype, suggesting high sensitivity of CD97 for this tumor. Ultrastructural analysis of murine skeletal myofibers confirmed the location of CD97 in the SR. CD97 knock-out mice had a dilated SR, resulting in a partial increase in triad diameter yet not affecting the T-tubule, sarcomeric, and mitochondrial structure. Despite these obvious ultrastructural changes, intracellular Ca2+ release from single myofibers, force generation and fatigability of isolated soleus muscles, and wheel-running capacity of mice were not affected by the lack of CD97. We conclude that CD97 is located in the SR and at the peripheral sarcolemma of human and murine skeletal muscle, where its absence affects the structure of the SR without impairing skeletal muscle function.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Sodium pyruvate, Hybri-Max, powder, suitable for hybridoma
Sigma-Aldrich
Sodium pyruvate, powder, BioReagent, suitable for cell culture, suitable for insect cell culture, ≥99%
Sigma-Aldrich
Sodium pyruvate, ReagentPlus®, ≥99%
Sigma-Aldrich
Sodium pyruvate, powder, BioXtra, suitable for mouse embryo cell culture
Sigma-Aldrich
Sodium pyruvate, BioXtra, ≥99%
Supelco
Melting point standard 235-237°C, analytical standard
Caffeine for system suitability, European Pharmacopoeia (EP) Reference Standard
Sigma-Aldrich
Sodium pyruvate, anhydrous, free-flowing, Redi-Dri, ReagentPlus®, ≥99%
Supelco
Mettler-Toledo Calibration substance ME 18872, Caffeine, traceable to primary standards (LGC)
Sigma-Aldrich
Caffeine, powder, ReagentPlus®
Sigma-Aldrich
β-D-Allose, rare aldohexose sugar
Sigma-Aldrich
Caffeine, BioXtra
Sigma-Aldrich
Caffeine, meets USP testing specifications, anhydrous
Sigma-Aldrich
Caffeine, Sigma Reference Standard, vial of 250 mg
Sigma-Aldrich
Caffeine, anhydrous, tested according to Ph. Eur.
USP
Caffeine melting point standard, United States Pharmacopeia (USP) Reference Standard
Supelco
Caffeine, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
Caffeine Melting Point Standard, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
Caffeine, certified reference material, TraceCERT®, Manufactured by: Sigma-Aldrich Production GmbH, Switzerland
Sigma-Aldrich
Caffeine, anhydrous, 99%, FCC, FG
USP
Caffeine, United States Pharmacopeia (USP) Reference Standard
Caffeine, European Pharmacopoeia (EP) Reference Standard