scholarly journals Collagen expression, ultrastructural assembly, and mineralization in cultures of chicken embryo osteoblasts.

1988 ◽  
Vol 106 (3) ◽  
pp. 979-989 ◽  
Author(s):  
L C Gerstenfeld ◽  
S D Chipman ◽  
C M Kelly ◽  
K J Hodgens ◽  
D D Lee ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Protein Synthesis ◽  
Collagen Synthesis ◽  
Collagen Fibrils ◽  
Collagen Molecule ◽  
Type I ◽  
Mrna Levels ◽  
Total Collagen ◽  
Cell Layers ◽  
Kinetics Of

A newly defined chick calvariae osteoblast culture system that undergoes a temporal sequence of differentiation of the osteoblast phenotype with subsequent mineralization (Gerstenfeld, L. C., S. Chipman, J. Glowacki, and J. B. Lian. 1987. Dev. Biol. 122:49-60) has been examined for the regulation of collagen synthesis, ultrastructural organization of collagen fibrils, and extracellular matrix mineralization. Collagen gene expression, protein synthesis, processing, and accumulation were studied in this system over a 30-d period. Steady state mRNA levels for pro alpha 1(I) and pro alpha 2 collagen and total collagen synthesis increased 1.2- and 1.8-fold, respectively, between days 3 and 12. Thereafter, total collagen synthesis decreased 10-fold while mRNA levels decreased 2.5-fold. In contrast to the decreasing protein synthesis after day 12, total accumulated collagen in the cell layers increased sixfold from day 12 to 30. Examination of the kinetics of procollagen processing demonstrated that there was a sixfold increase in the rate of procollagen conversion to alpha chains from days 3 to 30 and the newly synthesized collagen was more efficiently incorporated into the extracellular matrix at later culture times. The macrostructural assembly of collagen and its relationship to culture mineralization were also examined. High voltage electron microscopy demonstrated that culture cell layers were three to four cells thick. Each cell layer was associated with a layer of well developed collagen fibrils orthogonally arranged with respect to adjacent layers. Fibrils had distinct 64-70-nm periodicity typical of type I collagen. Electron opaque areas found principally associated with the deepest layers of the fibrils consisted of calcium and phosphorus determined by electron probe microanalysis and were identified by electron diffraction as a very poorly crystalline hydroxyapatite mineral phase. These data demonstrate for the first time that cultured osteoblasts are capable of assembling their collagen fibrils into a bone-specific macrostructure which mineralizes in a manner similar to that characterized in vivo. Further, this matrix maturation may influence the processing kinetics of the collagen molecule.

mRNA levels for α-subunit of prolyl 4-hydroxylase and fibrillar collagens in immobilized rat skeletal muscle

1999 ◽  
Vol 87 (1) ◽  
pp. 90-96 ◽  
Author(s):  
Xiao-Yan Han ◽  
Wei Wang ◽  
Raili Myllylä ◽  
Paula Virtanen ◽  
Jarmo Karpakka ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Tibialis Anterior ◽  
Collagen Synthesis ◽  
Plantar Flexion ◽  
Mrna Level ◽  
Type I ◽  
Mrna Levels ◽  
Rat Skeletal Muscle ◽  
Α Subunit ◽  
Fibrillar Collagens

There is evidence that immobilization causes a decrease in total collagen synthesis in skeletal muscle within a few days. In this study, early immobilization effects on the expression of prolyl 4-hydroxylase (PH) and the main fibrillar collagens at mRNA and protein levels were investigated in rat skeletal muscle. The right hindlimb was immobilized in full plantar flexion for 1, 3, and 7 days. Steady-state mRNAs for α- and β-subunits of PH and type I and III procollagen, PH activity, and collagen content were measured in gastrocnemius and plantaris muscles. Type I and III procollagen mRNAs were also measured in soleus and tibialis anterior muscles. The mRNA level for the PH α-subunit decreased by 49 and 55% ( P < 0.01) in gastrocnemius muscle and by 41 and 39% ( P < 0.05) in plantaris muscle after immobilization for 1 and 3 days, respectively. PH activity was decreased ( P < 0.05–0.01) in both muscles at days 3 and 7. The mRNA levels for type I and III procollagen were decreased by 26–56% ( P < 0.05–0.001) in soleus, tibialis anterior, and plantaris muscles at day 3. The present results thus suggest that pretranslational downregulation plays a key role in fibrillar collagen synthesis in the early phase of immobilization-induced muscle atrophy.

Increased extracellular matrix synthesis and mRNA in mesangial cells grown in high-glucose medium

1991 ◽  
Vol 260 (2) ◽  
pp. F185-F191 ◽  
Author(s):  
S. H. Ayo ◽  
R. A. Radnik ◽  
W. F. Glass ◽  
J. A. Garoni ◽  
E. R. Rampt ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Protein Synthesis ◽  
High Glucose ◽  
Mesangial Cells ◽  
Matrix Proteins ◽  
Cell Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mrna Levels ◽  
Glomerular Mesangial Cells ◽  
Glomerular Mesangium

Nodular expansion of glomerular mesangium with increased amounts of extracellular matrix (ECM) material is pathognomic of diabetic nephropathy. The precise mechanisms involved in this accumulation are unknown. Recently, we reported using a solid-phase enzyme-linked immunosorbent assay (ELISA) technique that glomerular mesangial cells, the principal cell type residing in glomerular mesangium, accumulate 50–60% more fibronectin (FN), laminin (LM), and type IV collagen (T-IV) when cultured in medium containing high glucose (30 mM) (S. H. Ayo, R. A. Rodnik, J. Garoni, W. F. Glass II, and J. I. Kreiberg. Am. J. Pathol. 136: 1339-1348, 1990). ECM assembly is controlled by its rate of synthesis and degradation, as well as its binding and rate of incorporation into the ECM. To elucidate the mechanisms involved, pulse-chase experiments were designed to estimate ECM protein synthesis from the incorporation of Trans-35S [( 35S]methionine, [35S]cysteine) into immunoprecipitated FN, LM, and T-IV. mRNA levels were examined, and degradation rates were estimated from the disappearance of radioactivity from matrix proteins in mesangial cells previously incubated with Trans-35S. One week of growth in 30 mM glucose resulted in approximately 40–50% increase in the synthesis of all three matrix proteins compared with 10 mM glucose-grown cells. This was accompanied by a significant increase in the transcripts for all three matrix proteins (approximately twofold). The specific activity of the radiolabel in trichloroacetic acid-precipitable cell protein showed no difference between cells grown in 10 or 30 mM glucose, indicating that total protein synthesis was unchanged. After 1 wk, the rate of FN, LM, and T-IV collagen degradation was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Collagen synthesis by cultured rabbit aortic smooth-muscle cells. Alteration with phenotype

1990 ◽  
Vol 265 (2) ◽  
pp. 461-469 ◽  
Author(s):  
A H Ang ◽  
G Tachas ◽  
J H Campbell ◽  
J F Bateman ◽  
G R Campbell
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Collagen Synthesis ◽  
Type I Collagen ◽  
Type Iii Collagen ◽  
Type I ◽  
Mrna Levels ◽  
Aortic Smooth Muscle ◽  
Phenotypic State ◽  
Synthetic Phenotype

Enzymically isolated rabbit aortic smooth-muscle cells (SMC) in the first few days of primary culture express a ‘contractile phenotype’, but with time these cells modulate to a ‘synthetic phenotype’. Synthetic-state SMC are able to proliferate, and, provided that they undergo fewer than 5 cumulative population doublings, return to the contractile phenotype after reaching confluency [Campbell, Kocher, Skalli, Gabbiani & Campbell (1989) Arteriosclerosis 9, 633-643]. The present study has determined the synthesis of collagen, at the protein and mRNA levels, by cultured SMC as they undergo a change in phenotypic state. The results show that, upon modulating to the synthetic phenotype, SMC synthesized 25-30 times more collagen than did contractile cells. At the same time, non-collagen-protein synthesis increased only 5-6-fold, indicating a specific stimulation of collagen synthesis. Steady-state mRNA levels are also elevated, with alpha 2(I) and alpha 1(III) mRNA levels 30 times and 20 times higher respectively, probably reflecting increased transcriptional activity. Phenotypic modulation was also associated with an alteration in the relative proportions of type I and III collagens synthesized, contractile SMC synthesizing 78.1 +/- 3.6% (mean +/- S.D.) type I collagen and 17.5 +/- 4.7% type III collagen, and synthetic cells synthesizing 90.3 +/- 2.0% type I collagen and 5.8% +/- 1.8% type III collagen. Enrichment of type I collagen was similarly noted at the mRNA level. On return to the contractile state, at confluency, collagen production and the percentage of type I collagen decreased. This further illustrates the close association between the phenotypic state of SMC and their collagen-biosynthetic phenotype.

scholarly journals Interleukin-10 inhibits the osteogenic activity of mouse bone marrow

Blood ◽  
1993 ◽  
Vol 82 (8) ◽  
pp. 2361-2370 ◽  
Author(s):  
P Van Vlasselaer ◽  
B Borremans ◽  
R Van Den Heuvel ◽  
U Van Gorp ◽  
R de Waal Malefyt
Keyword(s):  
Bone Marrow ◽  
Extracellular Matrix ◽  
Osteogenic Differentiation ◽  
Interleukin 10 ◽  
Mouse Bone Marrow ◽  
Type I ◽  
Mrna Levels ◽  
Differentiation Potential ◽  
Alp Activity ◽  
Bone Proteins

Abstract Murine bone marrow cells synthesize bone proteins, including alkaline phosphatase (ALP), collagen type I, and osteocalcin, and form a mineralized extracellular matrix when cultured in the presence of beta- glycerophosphate and vitamin C. Interleukin-10 (IL-10) suppressed the synthesis of these bone proteins and mineralization without affecting cell proliferation. In addition, mRNA levels for the latter proteins were reduced in IL-10-treated cultures. This inhibitory effect was most outspoken when IL-10 was added before ALP activity peaked, eg, day 15 of culture. No significant effect was observed when IL-10 was added at later time points. This finding suggests that IL-10 acts at osteogenic differentiation stages that precede ALP expression but is ineffective on cells that progressed beyond this maturation stage. Likewise, IL-10 appeared to be unable to block both ALP activity and collagen synthesis in the preosteosteoblastic cell lines MN7 and MC3T3 that constitutively synthesize these proteins. Whereas IL-10 did not alter the number of fibroblast colony-forming cells of the marrow, it significantly reduced their osteogenic differentiation potential. In contrast to control cultures, IL-10-treated stroma was unable to either synthesize osteocalcin or to mineralize when subcultured over a 25-day period in the absence of IL-10. The inhibitory activity of IL-10 coincided with significant changes in stroma morphology. Whereas control cultures contained mainly flat adherent polygonal cells, significant numbers of rounded semiadherent to nonadherent cells were observed in the presence of IL-10. Scanning and transmission electron microscopy showed that, in contrast to control cultures, IL-10-treated stromas completely lacked a mineralized extracellular matrix. Collectively, these data suggest that IL-10 may have important regulatory effects on bone biology because of its capacity to downregulate early steps of osteogenic differentiation.

Type V collagen synthesis and deposition by chicken embryo corneal fibroblasts in vitro

1989 ◽  
Vol 94 (2) ◽  
pp. 371-379
Author(s):  
J.S. McLaughlin ◽  
T.F. Linsenmayer ◽  
D.E. Birk
Keyword(s):  
Collagen Synthesis ◽  
Type I Collagen ◽  
Fibrillar Structure ◽  
Type I ◽  
Homogeneous Population ◽  
Type V Collagen ◽  
Total Collagen ◽  
Corneal Fibroblasts ◽  
Type V

Chick embryo corneal fibroblasts were grown in culture to study the processes whereby fibroblasts regulate the deposition and organization of the collagenous, secondary stroma. The effects of an existing type I collagen substratum, cell density, and serum concentration on type V collagen synthesis were investigated. Type V collagen represented approximately 20% of the total fibrillar collagen synthesized, regardless of whether the cells were subcultured, grown on untreated or collagen-coated plastic, grown under confluent or subconfluent conditions, or grown in the presence of low (0.1%) or high (10.0%) serum concentrations. The synthesis of type V collagen remained constant at 20% of the total collagen when cells were grown in 1.0% serum, even though total collagen synthesis increased nearly twofold when compared to total synthesis in 0.1% or 10.0% serum. Immunocytochemistry with anti-collagen, type-specific monoclonal antibodies revealed a homogeneous population of cells synthesizing types I and V collagen. The fibrils deposited by cells grown in a three-dimensional collagen matrix contained a helical epitope on the type V molecule that was inaccessible unless the fibrillar structure was disrupted, mimicking the situation in situ. The production in vitro of heterotypic fibrils, with a constant I/V ratio and molecular packing mimicking the natural stroma, offers opportunities for studying in more detail this important process, which is essential for optical transparency.

Modulation of type X collagen gene expression by calcium beta-glycerophosphate and levamisole: implications for a possible role for type X collagen in endochondral bone formation

1990 ◽  
Vol 95 (4) ◽  
pp. 639-648
Author(s):  
J.T. Thomas ◽  
R.P. Boot-Handford ◽  
M.E. Grant
Keyword(s):  
Collagen Synthesis ◽  
Mrna Translation ◽  
Endochondral Bone Formation ◽  
Type I ◽  
Collagen Gene ◽  
Mrna Levels ◽  
Collagen Gels ◽  
Type X Collagen ◽  
Total Rna ◽  
The Matrix

Chondrocytes from the cephalic region of 18-day chick embryo sterna were cultured within type I collagen gels in the presence of increasing concentrations of calcium beta-glycerophosphate (Ca beta GP) (2.5 mM, 5 mM and 10 mM) or 2 mM levamisole. Addition of Ca beta GP produced an increase in type X collagen synthesis and when 10 mM Ca beta GP was used, mineral deposits were observed in the matrix elaborated by the chondrocytes. Measurement of mRNA levels of type II and type X collagen microgram-1 total RNA revealed that the level of alpha 1(II) mRNA decreased whereas the level of alpha 1(X) mRNA remained relatively constant in the presence of Ca beta GP. Thus, Ca beta GP appears to increase type X collagen synthesis by enhancing the rate of collagen type X mRNA translation. In levamisole-treated cultures the synthesis of type X collagen and its deposition within the matrix were inhibited. Measurement of mRNA levels micrograms-1 total RNA revealed that the level of alpha 1(II) mRNA increased whereas the level of alpha 1(X) mRNA was markedly decreased in the presence of levamisole. Consequently, it must be concluded that levamisole inhibits type X collagen synthesis by inhibiting type X collagen gene transcription. These results add support for type X collagen having an important role in the mineralization process and have demonstrated that type X collagen synthesis is probably regulated at the mRNA translational stage during chondrocyte hypertrophy.

Immunohistochemical profile of the dermis at the injection of polylactic acid

2020 ◽  
Vol 28 (1) ◽  
pp. 23-29
Author(s):  
G. M. Mogil’naya ◽  
E. V. Fomicheva ◽  
Yu. E. Blatt
Keyword(s):  
Extracellular Matrix ◽  
Polylactic Acid ◽  
Inflammatory Reaction ◽  
Collagen Synthesis ◽  
Polyclonal Antibodies ◽  
The Body ◽  
Type Iii Collagen ◽  
Type I ◽  
Subsequent Transformation ◽  
Remodeling Of Extracellular Matrix

The regeneration of the skin in the event of damage to the introduction of fillers is due to the resulting inflammatory reaction of the dermis. Among the vast group of fillers used in aesthetic medicine, polylactic acid, which is recommended as a “scaffold” forming factor that induces collagen synthesis by fibroblasts with subsequent transformation of this type of cells into myofibroblasts, has proven itself quite well. The aim of the study was to analyze the immunohistochemical status of the dermis with the introduction of an implant from polylactic acid. The study was performed on 30 rats with subdermal administration of the drug in a volume of 0.05 ml. Evaluation of the results was carried out two weeks later, 1, 2 and 4 months after the injection. Morphological evaluation was carried out in sections stained with hematoxylin and eosin according to Van Gieson and Mallory and Masson reactions. Immunohistochemical detection of type I and type III collagen was performed using polyclonal antibodies. Vimentin was used to assess the status of fibroblasts, and the marker CD68 to assess macrophages. The effect of remodeling of extracellular matrix was studied using α-SMA actin. It was shown that the response of the dermis to the implant is of a phase nature, begins with a subclinical inflammatory reaction, followed by encapsulation of each individual microsphere, and ends with dermal fibroplasia. This leads to the effect of increasing the volume of tissue and the result is achieved not only by properties of the introduced product, but also by the reaction of the body to its introduction. The detected activation of collagen synthesis by fibroblasts can be used as a regulator of the volume of the extracellular matrix of the dermis.

scholarly journals Immunological and biochemical studies of collagen type transition during in vitro chondrogenesis of chick limb mesodermal cells

1977 ◽  
Vol 73 (3) ◽  
pp. 736-747 ◽  
Author(s):  
K Von Der Mark ◽  
H Von Der Mark
Keyword(s):  
Collagen Synthesis ◽  
Type I Collagen ◽  
Type Ii Collagen ◽  
Mesenchymal Cells ◽  
Gradual Transition ◽  
Type I ◽  
Type Ii ◽  
Total Collagen ◽  
Collagen Antibodies

This work describes an approach to monitor chondrogenesis of stage-24 chick limb mesodermal cells in vitro by analyzing the onset of type II collagen synthesis with carboxymethyl-cellulose chromatography, immunofluorescence, and radioimmunoassay. This procedure allowed specific and quantitative determination of chondrocytes in the presence of fibroblasts and myoblasts, both of which synthesize type I collagen. Chondrogenesis was studied in high-density cell preparations on tissue culture plastic dishes and on agar base. It was found that stage-24 limb mesenchymal cells initially synthesized only type I collagen. With the onset of chondrogenesis, a gradual transition to type II collagen synthesis was observed. In cell aggregates formed over agar, type II collagen synthesis started after 1 day in culture and reached levels of 80-90 percent of the total collagen synthesis at 6-8 days. At that time, the cells in the center of the aggregates had acquired the typical chondrocyte phenotype and stained only with type II collagen antibodies, whereas the peripheral cells had developed into a "perichondrium" and stained with type I and type II collagen antibodies. On plastic dishes plated with 5 X 10(6) cells per 35mm dish, cartilage nodules developed after 4-6 days, but the type II collagen synthesis only reached levels of 10-20 percent of the total collagen. The majority of the cells differentiated into fibroblasts and myoblasts and synthesized type I collagen. These studies demonstrate that analysis of cell specific types of collagen provides a useful method for detailing the specific events in the differentiation of mesenchymal cells in vitro.

Molecular mobility in the gap regions of type 1 collagen fibrils

1986 ◽  
Vol 6 (2) ◽  
pp. 221-226 ◽  
Author(s):  
R. D. B. Fraser ◽  
B. L. Trus
Keyword(s):  
Type I Collagen ◽  
Collagen Fibrils ◽  
Collagen Molecule ◽  
Type I ◽  
Amino Acid Residues ◽  
Linear Distribution ◽  
Uniform Distributions ◽  
Imino Acid ◽  
Hydropathy Index

Recent studies of the structure of Type I collagen fibrils (Piez and Trus, Biosci. Rep.1:801–810, 1981; Fraser, MacRae, Miller and Suzuki, J. Mol. Biol.167:497–521, 1983) suggest that the segments of the collagen molecule which comprise the gap region are more mobile than those which comprise the overlap region. We have analyzed the distribution of amino acid residues and triplet types between the two regions, and find significantly non-uniform distributions for Ala, Gln, His, Hyp, Leu, Phe, and Tyr, and for triplets containing two imino acid residues. Taken together with the lower packing density in the gap region these observations provide a basis for understanding the greater mobility of the molecular segments in the gap region. In addition, we have examined the linear distribution of residue types in the two regions and also the hydropathy profile (Kyte and Doolittle, J. Mol. Biol.157: 105–113, 1982). These reveal a segment of the gap region comprising helical residues 165–173, 399–407, 633–641 and 867–975 which has the highest hydropathy index, is devoid of charged residues, and contains very high proportions of Ala, Hyp and Phe.

scholarly journals Stepwise proteolytic activation of type I procollagen to collagen within the secretory pathway of tendon fibroblasts in situ

2011 ◽  
Vol 441 (2) ◽  
pp. 707-717 ◽  
Author(s):  
Elizabeth G. Canty-Laird ◽  
Yinhui Lu ◽  
Karl E. Kadler
Keyword(s):  
Extracellular Matrix ◽  
Secretory Pathway ◽  
Brefeldin A ◽  
Collagen Fibrils ◽  
Proteinase Activity ◽  
Type I ◽  
Proteolytic Activation ◽  
Type I Procollagen ◽  
Tail Tendon

Proteolytic cleavage of procollagen I to collagen I is essential for the formation of collagen fibrils in the extracellular matrix of vertebrate tissues. Procollagen is cleaved by the procollagen N- and C-proteinases, which remove the respective N- and C-propeptides from procollagen. Procollagen processing is initiated within the secretory pathway in tendon fibroblasts, which are adept in assembling an ordered extracellular matrix of collagen fibrils in vivo. It was thought that intracellular processing was restricted to the TGN (trans-Golgi network). In the present study, brefeldin A treatment of tendon explant cultures showed that N-proteinase activity is present in the resulting fused ER (endoplasmic reticulum)–Golgi compartment, but that C-proteinase activity is restricted to the TGN in embryonic chick tendon fibroblasts. In late embryonic and postnatal rat tail and postnatal mouse tail tendon, C-proteinase activity was detected in TGN and pre-TGN compartments. Preventing activation of the procollagen N- and C-proteinases with the furin inhibitor Dec-RVKR-CMK (decanoyl-Arg-Val-Lys-Arg-chloromethylketone) indicated that only a fraction of intracellular procollagen cleavage was mediated by newly activated proteinases. In conclusion, the N-propeptides are removed earlier in the secretory pathway than the C-propeptides. The removal of the C-propeptides in post-Golgi compartments most probably indicates preparation of collagen molecules for fibril formation at the cell–matrix interface.

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