Type VI collagen forms a structural association with hyaluronan in vivo

1991 ◽  
Vol 19 (4) ◽  
pp. 384S-384S ◽  
Author(s):  
CAY M. KIELTY ◽  
STEPHEN P. WHITTAKER ◽  
MICHAEL E. GRANT ◽  
C. ADRIAN SHUTTLEWORTH
Keyword(s):  
Type Vi Collagen ◽  
Structural Association

Type VI collagen induces cardiac myofibroblast differentiation: implications for postinfarction remodeling

2006 ◽  
Vol 290 (1) ◽  
pp. H323-H330 ◽  
Author(s):  
Jennifer E. Naugle ◽  
Erik R. Olson ◽  
Xiaojin Zhang ◽  
Sharon E. Mase ◽  
Charles F. Pilati ◽  
...  
Keyword(s):  
Cardiac Fibrosis ◽  
Type I Collagen ◽  
In Vivo Model ◽  
Type Iii Collagen ◽  
Type I ◽  
Myofibroblast Differentiation ◽  
Type Vi Collagen ◽  
Collagen Substrate ◽  
Type Iii

Cardiac fibroblast (CF) proliferation and differentiation into hypersecretory myofibroblasts can lead to excessive extracellular matrix (ECM) production and cardiac fibrosis. In turn, the ECM produced can potentially activate CFs via distinct feedback mechanisms. To assess how specific ECM components influence CF activation, isolated CFs were plated on specific collagen substrates (type I, III, and VI collagens) before functional assays were carried out. The type VI collagen substrate potently induced myofibroblast differentiation but had little effect on CF proliferation. Conversely, the type I and III collagen substrates did not affect differentiation but caused significant induction of proliferation (type I, 240.7 ± 10.3%, and type III, 271.7 ± 21.8% of basal). Type I collagen activated ERK1/2, whereas type III collagen did not. Treatment of CFs with angiotensin II, a potent mitogen of CFs, enhanced the growth observed on types I and III collagen but not on the type VI collagen substrate. Using an in vivo model of myocardial infarction (MI), we measured changes in type VI collagen expression and myofibroblast differentiation after post-MI remodeling. Concurrent elevations in type VI collagen and myofibroblast content were evident in the infarcted myocardium 20-wk post-MI. Overall, types I and III collagen stimulate CF proliferation, whereas type VI collagen plays a potentially novel role in cardiac remodeling through facilitation of myofibroblast differentiation.

scholarly journals Secretion and Assembly of Type IV and VI Collagens Depend on Glycosylation of Hydroxylysines

2007 ◽  
Vol 282 (46) ◽  
pp. 33381-33388 ◽  
Author(s):  
Laura Sipilä ◽  
Heli Ruotsalainen ◽  
Raija Sormunen ◽  
Naomi L. Baker ◽  
Shireen R. Lamandé ◽  
...  
Keyword(s):  
Congenital Muscular Dystrophy ◽  
Basement Membranes ◽  
Collagen Vi ◽  
Collagen Types ◽  
Type Vi Collagen ◽  
Knock Out ◽  
Type Iv ◽  
New Information ◽  
Ullrich Congenital Muscular Dystrophy

Most lysines in type IV and VI collagens are hydroxylated and glycosylated, but the functions of these unique galactosylhydroxylysyl and glucosylgalactosylhydroxylysyl residues are poorly understood. The formation of glycosylated hydroxylysines is catalyzed by multifunctional lysyl hydroxylase 3 (LH3) in vivo, and we have used LH3-manipulated mice and cells as models to study the function of these carbohydrates. These hydroxylysine-linked carbohydrates were shown recently to be indispensable for the formation of basement membranes (Ruotsalainen, H., Sipilä, L., Vapola, M., Sormunen, R., Salo, A. M., Uitto, L., Mercer, D. K., Robins, S. P., Risteli, M., Aszodi, A., Fässler, R., and Myllylä, R. (2006) J. Cell Sci. 119, 625–635). Analysis of LH3 knock-out embryos and cells in this work indicated that loss of glycosylated hydroxylysines prevents the intracellular tetramerization of type VI collagen and leads to impaired secretion of type IV and VI collagens. Mice lacking the LH activity of LH3 produced slightly underglycosylated type IV and VI collagens with abnormal distribution. The altered distribution and aggregation of type VI collagen led to similar ultrastructural alterations in muscle to those detected in collagen VI knockout and some Ullrich congenital muscular dystrophy patients. Our results provide new information about the function of hydroxylysine-linked carbohydrates of collagens, indicating that they play an important role in the secretion, assembly, and distribution of highly glycosylated collagen types.

scholarly journals Bovine cartilage types VI and IX collagens. Characterization of their forms in vivo

1989 ◽  
Vol 262 (3) ◽  
pp. 753-761 ◽  
Author(s):  
S Ayad ◽  
A Marriott ◽  
K Morgan ◽  
M E Grant
Keyword(s):  
Molecular Mass ◽  
Proteinase Inhibitors ◽  
Guanidinium Chloride ◽  
Type Vi Collagen ◽  
Pepsin Digestion ◽  
Molecular Masses ◽  
Biosynthetic Studies ◽  
Bovine Cartilage

1. Collagens were extracted from bovine cartilage by 4 M-guanidinium chloride in the presence of proteinase inhibitors and identified by immunoblotting with specific anti-collagen sera. 2. The collagens retained their native conformations (shown by the resistance of their triple-helical domains to pepsin digestion), and the molecular masses of their component alpha-chains indicated that the chains were intact. 3. Type VI collagen was extracted as a large-molecular-mass disulphide-bonded aggregate composed of components of molecular mass 140 kDa and 200-240 kDa, and was therefore similar to type VI collagen identified in noncartilaginous tissues. Immunoblotting established the 200-240 kDa components as intact forms of the alpha 3(VI) chain. 4. Type IX collagen consisted of three clearly separable components of molecular mass 84 kDa, 72 kDa and 66 kDa, which were assigned to the alpha 1(IX)-, alpha 3(IX)- and alpha 2(IX)-chains respectively, and a large proportion of this collagen had no covalently bound glycosaminoglycan attached to the alpha 2(IX)-chain. 5. Differences between the type IX collagen extracted from bovine cartilage and that identified in biosynthetic studies on chick cartilage are discussed.

scholarly journals Type VI collagen microfibrils: evidence for a structural association with hyaluronan.

1992 ◽  
Vol 118 (4) ◽  
pp. 979-990 ◽  
Author(s):  
C M Kielty ◽  
S P Whittaker ◽  
M E Grant ◽  
C A Shuttleworth
Keyword(s):  
Gel Filtration ◽  
Microscopic Analysis ◽  
Connective Tissues ◽  
Binding Studies ◽  
Collagen Vi ◽  
Electron Microscopic ◽  
Type Vi Collagen ◽  
Structural Association ◽  
Fetal Bovine

Type VI collagen, a widespread structural component of connective tissues, has been isolated in abundance from fetal bovine skin by a procedure involving bacterial collagenase digestion under nonreducing, nondenaturing conditions and gel filtration chromatography. Rotary shadowing electron microscopic analysis revealed that the collagen VI was predominantly in the form of extensive intact microfibrillar arrays. These microfibrils were seen in association with hyaluronan, which was identified by its ability to bind the G1 fragment of cartilage proteoglycan. Treatment with highly purified hyaluronidase largely disrupted the collagen VI microfibrils into component tetramers, double tetramers, and short microfibrillar sections. Subsequent incubation of disrupted collagen VI in the presence of hyaluronan facilitated a partial repolymerization of the microfibrils. In vitro binding studies have also demonstrated that type VI collagen binds hyaluronan with a relatively high affinity. These studies demonstrate that a specific structural relationship exists between type VI collagen and hyaluronan. This association is likely to be of primary importance in the growth and remodeling processes of connective tissues.

scholarly journals Improved cardiac remodeling after in vivo knockdown of type VI collagen following myocardial infarction

2018 ◽  
Vol 32 (S1) ◽  
Author(s):  
Nicholas J. Baker ◽  
Ashot Minasyan ◽  
Ravi Adapala ◽  
Christian M. McShannic ◽  
Connie Gan ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Remodeling ◽  
Type Vi Collagen

Correlative light and electron microscopy of primary (9+0) cilia: Response of ciliary varicosities to hypotonic treatment in kidney epithelial cells

1992 ◽  
Vol 50 (1) ◽  
pp. 572-573
Author(s):  
Samuel S. Bowser ◽  
Karen E. Roth ◽  
Conly L. Rieder
Keyword(s):  
Electron Microscopy ◽  
Golgi Apparatus ◽  
Cell Surface ◽  
Primary Cilia ◽  
Apical Cell ◽  
Light And Electron Microscopy ◽  
Kidney Tubule ◽  
Hypotonic Treatment ◽  
Structural Association

Primary cilia are centrosomal appendages which in kidney epithelia extend several micrometers from the apical cell surface into the lumen of the kidney tubule. Although considered by some to be “rudimentary appendages” because they are nonmotile, their intimate structural association with the Golgi apparatus and nucleus suggests to others that they mediate interactions between the cell and its environment. Such a sensory role is not without precedence since various photo- and chemoreceptors are highly modified primary cilia. Despite the near-ubiquitous distribution of primary cilia few studies have addressed their function experimentally, and little detailed information is available regarding their behavior in vivo.

scholarly journals Cloning of α2 chain of type VI collagen and expression during mouse development

1993 ◽  
Vol 289 (1) ◽  
pp. 141-147 ◽  
Author(s):  
A Ibrahimi ◽  
B Bertrand ◽  
S Bardon ◽  
E Z Amri ◽  
P Grimaldi ◽  
...  
Keyword(s):  
Adrenal Glands ◽  
Cdna Probe ◽  
C2c12 Cell ◽  
Cdna Libraries ◽  
Mouse Development ◽  
Type Vi Collagen ◽  
Mrna Species ◽  
Polyadenylation Sites

We have previously described the molecular cloning of a cDNA probe which detects a 6 kb mRNA termed pOb24. pOb24 mRNA appeared to be a marker of the preadipose state both in vitro and in vivo. A pOb24 genomic fragment was isolated and used to screen cDNA libraries in order to isolate the full-length pOb24 cDNA and to identify the corresponding protein. The screening yielded a new cDNA clone which detected a 3.7 kb mRNA species in addition to the 6 kb mRNA species. Sequences at the 3′ end of the 6 kb and 3.7 kb mRNAs indicate that both mRNAs are generated from the same gene through the use of two different polyadenylation sites. The protein encoded by the 3.7 kb mRNA appeared to be homologous to the human alpha 2 chain of type VI collagen (A2COL6). The expression of the A2COL6 gene was not confined to adipose tissue; mRNA species can be detected in ovaries, adrenal glands and lungs but not in liver and skeletal muscle. The expression appeared specific for initial phase(s) of cell differentiation since it is parallel to that of the MyoD1 gene during muscle embryogenesis in vivo. In the myogenic C2C12 cell line, the A2COL6 gene exhibited the same regulation as MyoD1 and myogenin genes. These results indicate that A2COL6 gene expression is a marker of the preadipose state, but may also be a marker of other differentiation programmes such as that of muscle.

scholarly journals Isolation from bovine elastic tissues of collagen type VI and characterization of its form in vivo

1985 ◽  
Vol 230 (2) ◽  
pp. 465-474 ◽  
Author(s):  
S Ayad ◽  
C A Chambers ◽  
C A Shuttleworth ◽  
M E Grant
Keyword(s):  
Collagen Type ◽  
Elastic Fibre ◽  
Type Vi Collagen ◽  
Pregnant Uterus ◽  
Electrophoretic Mobilities ◽  
Standard Procedures ◽  
Collagen Type Vi ◽  
Nuchal Ligament

Foetal-bovine nuchal ligament and aorta, together with adult-bovine aorta and pregnant uterus, were extracted under dissociative conditions in the absence and in the presence of a reducing agent. A collagenous glycoprotein of Mr 140000 [designated component 140K(VI)], identified in these extracts as the major periodate/Schiff-positive component, was shown to be related to collagen type VI. Digestion of non-reduced extracts with pepsin yielded periodate/Schiff-positive peptides that, on the basis of their electrophoretic mobilities, amino acid analyses and peptide ‘maps’, were identical with type VI collagen fragments prepared by standard procedures. It is concluded that collagen type VI occurs in vivo as molecule comprising three chains of Mr 140000 in which the helical domains account for about one-third of each polypeptide. Biosynthetic experiments with nuchal-ligament fibroblasts in culture demonstrated that a bacterial-collagenase-sensitive [3H]fucose-labelled glycoprotein, Mr 140000, was immunoprecipitated from culture medium by a specific antibody to the pepsin-derived form of collagen type VI. This result suggests that the collagenous polypeptides [140K(VI) components] represent the biosynthetic precursors of type VI collagen that do not undergo processing to smaller species before deposition in the extracellular matrix. Analyses of 5M-guanidinium chloride extracts of tissues with markedly different elastin contents and at different stages of development suggested that there was no relationship between collagen type VI and elastic-fibre microfibrils, a conclusion supported by the observation that the immunoprecipitated glycoprotein, Mr 140000, was distinct from the glycoprotein MFPI, Mr 150000, believed to be a constituent of these microfibrils [Sear, Grant & Jackson (1981) Biochem. J. 194, 587-598].

Fine Structural Changes in the Microvasculature of the Mouse Pinna: Aging and Radiation Injury

1974 ◽  
Vol 32 ◽  
pp. 54-55
Author(s):  
S. Phyllis Steamer ◽  
Rosemarie L. Devine
Keyword(s):  
Structural Changes ◽  
Radiation Treatment ◽  
Arterial Stenosis ◽  
Ultrastructural Changes ◽  
Vascular Effects ◽  
Microvascular Changes ◽  
Surrounding Connective Tissue ◽  
Fission Neutrons ◽  
Total Body

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.

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