title: Transient expression of transglutaminase C during prenatal development of human muscles.
abstract: Tissue transglutaminase (TGase C, TGase II) is known to participate in cellular processes during morphogenesis, differentiation, and development of various prenatal tissues and organs. The expression of TGase C during myoblast proliferation and attachment to external laminae was examined by immunohistochemical (IH) localization at 5-12 weeks of developmental stages of prenatal human muscle in 23 embryos. IH detection using a monospecific antibody to TGase C showed a prominent expression of TGase C in muscle cells as stage- and spatial-specific patterns during an early embryonal period. The myoblasts of intervertebral, tongue, and limb muscles, attached to adjacent cartilaginous skeletons or fibrous fascia, showed a pronounced expression of TGase C at 5-6, 6-7, and 7-8 weeks after fertilization, respectively. The most intense activity of TGase C was observed in some cardiac myoblasts infiltrating into endocardial mesenchyme at 6-7 weeks after fertilization. Although weak staining was detected until 14 weeks after fertilization, the level of TGase C expression in all muscles was significantly decreased after 6-7 weeks, with the exception that the smooth muscle cells of blood vessels and gastrointestinal tract showed diffusely intense staining of TGase C between 5 and 12 weeks after fertilization. Western blotting analysis of the cellular extracts of pooled samples showed a single strong band at 80 kD at 6 weeks after fertilization. This band became weaker after 8-10 weeks of prenatal development. These findings of transient expression of TGase C, which coincides with the development of myoblast anchoring and differentiation, suggest that TGase C plays a role in myoblast attachment to the extracellular laminae during the early embryonal period.
authors.affiliation: Department of Oral Pathology, Kangnung National University College of Dentistry, Korea.
authors.forename: S K
authors.initials: SK
authors.lastname: Lee
authors.forename: J G
authors.initials: JG
authors.lastname: Chi
authors.forename: S C
authors.initials: SC
authors.lastname: Park
authors.forename: S I
authors.initials: SI
authors.lastname: Chung
mesh_terms: D015153:Blotting, Western; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D018482:Muscle, Skeletal / Q000196:embryology / Q000201:enzymology*; D009130:Muscle, Smooth / Q000196:embryology / Q000201:enzymology*; D009206:Myocardium / Q000201:enzymology; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D013131:Spine; D011503:Transglutaminases / Q000378:metabolism*
chemical_list: D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins