Differentiation of cell types in the mammalian kidney by immunofluorescence microscopy using antibodies to intermediate filament proteins and desmoplakins

Three morphologically distinct major cell types were observed in primary cultures obtained from the mammary parenchyma of glands from virgin rats. These cell types consisted of small cuboidal epithelial cells, larger epithelioid cells and elongated cells. We have investigated the distribution of the basement membrane proteins laminin and type IV collagen, and the intermediate filament proteins vimentin and prekeratin, in these three cell types using immunofluorescence techniques. Antisera to the basement membrane proteins stain the large epithelioid cells and the elongated cells, but do not stain the small cuboidal cells. Polyclonal antiserum to keratin stains all the small cuboidal and large epithelioid cells, but only a small subpopulation of the elongated cells. However, a monoclonal antibody to keratin, LP34, stains only the large cuboidal and a proportion of the elongated cells. Vimentin antiserum fails to stain the small cuboidal cells but stains all the large epithelioid and elongated cells. In addition, peanut lectin, which binds only to ductal lining epithelial cells in the virgin rat mammary gland in vivo after their treatment with neuraminidase, binds to the small cuboidal cells after neuraminidase treatment but not to the other cell types. However, Griffonia simplicifolia agglutinin I, which specifically stains myoepithelial cells in vivo, binds to the large epithelioid and elongated cells but not to the small cuboidal cells. These results suggest that the small cuboidal cells are related to mammary ductal epithelial cells whereas the large epithelial and elongated cells have some characteristics of myoepithelial cells.

Download Full-text

Cross-reactivity of antibodies specific for flagellar tektin and intermediate filament subunits.

The Journal of Cell Biology ◽

10.1083/jcb.104.6.1563 ◽

1987 ◽

Vol 104 (6) ◽

pp. 1563-1568 ◽

Cited By ~ 21

Author(s):

X J Chang ◽

G Piperno

Keyword(s):

Monoclonal Antibodies ◽

Intermediate Filament ◽

Immunofluorescence Microscopy ◽

Polyclonal Antibodies ◽

Nuclear Lamina ◽

Helical Structure ◽

Cross Reactivity ◽

Cytoskeletal Proteins ◽

Intermediate Filament Proteins ◽

Double Label

Monoclonal antibodies specific for each of the flagellar tektins were prepared and used to determine whether structures similar to tektin filaments are present in cells lacking cilia or flagella. This analysis was performed by double-label immunofluorescence microscopy of several cell lines and by immunoblots of protein fractions. Two of the four anti-tektin antibodies, the antibodies 3-7-1 and 3-10-1, which bind different epitopes of the C-tektin, label 3T3, HeLa, PtK2, and BHK-21 cells as well as myotubes. The antibody 3-7-1 stains intermediate filament structures in the cells and binds vimentin or desmin in preparations of cytoskeletal proteins; whereas the antibody 3-10-1 stains nuclear envelopes in the cells and binds lamin A and C in preparations of cytoskeletal proteins or nuclear lamina. Structural similarities between the C-tektin and intermediate filament proteins probably are extended to more than two epitopes because polyclonal antibodies anti-vimentin and anti-desmin bind to C-tektin. These polyclonal antibodies also bind to A-tektin. The cross-reaction of monoclonal and polyclonal antibodies binding to epitopes in tektin and intermediate filament components and the existence of a high content of alpha-helical structure in the tektin subunits (Linck, R. W., and G. L. Langevin, 1982, J. Cell Sci., 58:1-22) indicate that tektin and intermediate filaments are homologous in several parts of their structure.

Download Full-text

A novel photoactivatable tool for intermediate filament disruption indicates a role for keratin filaments in early embryogenesis

10.1101/484246 ◽

2018 ◽

Author(s):

Rucha Sanghvi-Shah ◽

Shalaka Paranjpe ◽

Jiyeon Baek ◽

Radek Dobrowolski ◽

Gregory F. Weber

Keyword(s):

Intermediate Filaments ◽

Intermediate Filament ◽

Cell Types ◽

Model Systems ◽

Intermediate Filament Proteins ◽

Morphogenetic Movements ◽

Cell Functions ◽

Filament Network ◽

Keratin Intermediate Filaments

AbstractThe significance of cytoplasmic intermediate filament proteins has previously been examined largely through various genetic approaches, including knockdown, knockout and transgenic overexpression. Few studies to date have attempted to examine the role of specifically the filamentous intermediate filament network in orchestrating various cell functions. To directly assess the role of the filamentous keratin intermediate filament network in regulation of cellular behavior, we created a PhotoActivatable disruptor of keratin Intermediate Filaments (PA-dIF). This genetically encoded construct consists of a peptide derived from the 2B2 region of Keratin 8 fused to the photosensitive LOV2 domain from Avena sativa phototropin-1. Upon 458 nm photoirradiation, PA-dIF disrupts keratin intermediate filaments in multiple species and cell types. Marked remodeling of the keratin intermediate filament network accompanies collective cellular morphogenetic movements that occur during gastrulation and neurulation in the Xenopus laevis frog embryo. Light-based activation of PA-dIF was able to disrupt keratin intermediate filaments in Xenopus cells and lead to tissue-specific disruption of morphogenetic processes. Altogether our data show a fundamental requirement for keratin intermediate filaments in orchestrating morphogenetic movements during early embryonic development that have yet to be revealed in other model systems. Moreover, our data validate the utility of a new genetically encoded photoactivatable tool for the disruption and examination of intermediate filaments.

Download Full-text

Faculty Opinions recommendation of Intermediate filament proteins of digestive organs: physiology and pathophysiology.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.727464772.793565301 ◽

2019 ◽

Author(s):

Michael Klymkowsky

Keyword(s):

Intermediate Filament ◽

Intermediate Filament Proteins ◽

Digestive Organs

Download Full-text

Skeletal and Cardiac Muscle Disorders Caused by Mutations in Genes Encoding Intermediate Filament Proteins

International Journal of Molecular Sciences ◽

10.3390/ijms22084256 ◽

2021 ◽

Vol 22 (8) ◽

pp. 4256

Author(s):

Lorenzo Maggi ◽

Manolis Mavroidis ◽

Stelios Psarras ◽

Yassemi Capetanaki ◽

Giovanna Lattanzi

Keyword(s):

Muscular Dystrophy ◽

Cardiac Muscle ◽

Intermediate Filament ◽

Striated Muscle ◽

Congenital Muscular Dystrophy ◽

Left Ventricular ◽

Intermediate Filament Proteins ◽

Muscle Disorders ◽

Genes Encoding ◽

Molecular Aspects

Intermediate filaments are major components of the cytoskeleton. Desmin and synemin, cytoplasmic intermediate filament proteins and A-type lamins, nuclear intermediate filament proteins, play key roles in skeletal and cardiac muscle. Desmin, encoded by the DES gene (OMIM *125660) and A-type lamins by the LMNA gene (OMIM *150330), have been involved in striated muscle disorders. Diseases include desmin-related myopathy and cardiomyopathy (desminopathy), which can be manifested with dilated, restrictive, hypertrophic, arrhythmogenic, or even left ventricular non-compaction cardiomyopathy, Emery–Dreifuss Muscular Dystrophy (EDMD2 and EDMD3, due to LMNA mutations), LMNA-related congenital Muscular Dystrophy (L-CMD) and LMNA-linked dilated cardiomyopathy with conduction system defects (CMD1A). Recently, mutations in synemin (SYNM gene, OMIM *606087) have been linked to cardiomyopathy. This review will summarize clinical and molecular aspects of desmin-, lamin- and synemin-related striated muscle disorders with focus on LMNA and DES-associated clinical entities and will suggest pathogenetic hypotheses based on the interplay of desmin and lamin A/C. In healthy muscle, such interplay is responsible for the involvement of this network in mechanosignaling, nuclear positioning and mitochondrial homeostasis, while in disease it is disturbed, leading to myocyte death and activation of inflammation and the associated secretome alterations.

Download Full-text