title: Alpha smooth muscle actin distribution in cytoplasm and nuclear invaginations of connective tissue fibroblasts.
abstract: Alpha smooth muscle actin (alpha-SMA) was recently shown to be present in mouse subcutaneous tissue fibroblasts in the absence of tissue injury. In this study, we used a combination of immunohistochemistry and correlative confocal scanning laser and electron microscopy to investigate the structural organization of alpha-SMA in relation to the nucleus. Furthermore, we explored colocalization analysis as a method for quantifying the amount of alpha-SMA in close approximation to the nucleic acid marker, 4',6-diamidino-2-phenyl-indole, dihydrochloride. Our findings indicate the presence of alpha-SMA within nuclear invaginations in close proximity to the nuclear membrane, but not in the nucleoplasm. Although the function of these alpha-SMA-rich nuclear invaginations is at present unknown, the morphology of these structures suggests their possible involvement in cellular and nuclear mechanotransduction as well as nuclear transport.
authors.affiliation: Department of Neurology, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington, VT 05405, USA.
authors.forename: Kirsten N
authors.initials: KN
authors.lastname: Storch
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Taatjes
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Bouffard
authors.forename: Sarah
authors.initials: S
authors.lastname: Locknar
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Bishop
authors.forename: Helene M
authors.initials: HM
authors.lastname: Langevin
mesh_terms: D000199:Actins / Q000032:analysis*; D000818:Animals; D003593:Cytoplasm / Q000737:chemistry; D005347:Fibroblasts / Q000737:chemistry* / Q000166:cytology / Q000648:ultrastructure; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D009130:Muscle, Smooth / Q000737:chemistry; D009685:Nuclear Envelope / Q000737:chemistry; D045663:Quantum Dots; D040521:Subcutaneous Tissue / Q000737:chemistry
chemical_list: D000199:Actins