scholarly journals THE LOSS OF PHENOTYPIC TRAITS BY DIFFERENTIATED CELLS

1966 ◽  
Vol 28 (3) ◽  
pp. 473-487 ◽  
Author(s):  
Joan Abbott ◽  
Howard Holtzer
Keyword(s):  
Dna Synthesis ◽  
Chondroitin Sulfate ◽  
Collagen Synthesis ◽  
Dna Interaction ◽  
Cell Multiplication ◽  
Phenotypic Traits ◽  
Embryonic Chick ◽  
Differentiated Cells ◽  
Genetically Determined

Observations were made on the behavior of chondrocytes grown under various conditions in vitro. The chondrocytes in 10-day embryonic chick vertebrae were grown as cultures of intact vertebrae, as pellets of chondrocytes liberated from their matrix, and as monodispersed cells plated out on plasma clots. Cartilage matrix was stained metachromatically with toluidine blue. Radioautographs were made of incorporated H3-thymidine, H3-proline, and S35-sulfate to determine the extent of DNA synthesis, collagen synthesis, and chondroitin sulfate synthesis, respectively. Chondrocytes in intact vertebrae or in pellets are rounded and actively synthesizing chondroitin sulfate and collagen. There is little DNA synthesis by cells in either vertebrae or pellets. Chondrocytes grown as monodisperse cells rapidly cease synthesizing cytologically detectable chondroitin sulfate and are induced to synthesize DNA and divide. There is a change in the shape of these chondrocytes from a rounded to a more stellate condition which accompanies the shift in metabolic activity. Conversely, when the cells attain a certain cell density, they reacquire a rounded shape, cease dividing, and again synthesize chondroitin sulfate. Clusters of chondrocytes synthesize more chondroitin sulfate than isolated chondrocytes. It is concluded that most chondrocytes synthesizing chondroitin sulfate do not concurrently synthesize DNA. Interaction between associated chondrocytes is important in inducing and maintaining chondroitin sulfate synthesis in genetically determined chondrocytes. Failure of interaction between chondrocytes leads to DNA synthesis and cell multiplication.

scholarly journals THE LOSS OF PHENOTYPIC TRAITS BY DIFFERENTIATED CELLS

1969 ◽  
Vol 130 (2) ◽  
pp. 417-442 ◽  
Author(s):  
S. Chacko ◽  
J. Abbott ◽  
S. Holtzer ◽  
H. Holtzer
Keyword(s):  
Cell Surface ◽  
Chondroitin Sulfate ◽  
Phenotypic Traits ◽  
Differentiated Cells ◽  
Chondrogenic Phenotype ◽  
History Of ◽  
A Cell ◽  
Fibroblastic Cells ◽  
Cell Cell

A single, functional, mitotically quiescent chondrocyte may be induced to reenter the mitotic cyde, and produce a progeny of over 1011 cells. Sessile, adherent, polygonal cells deposit matrix, whereas amoeboid, dispersed, flattened fibroblastic cells do not. The prior synthetic history of a cell is of greater importance in determining whether the characteristic chondrogenic phenotype will be expressed, rather than growth in "permissive" or "nonpermissive" medium. Clonal conditions select for stem-like cells, some of whose progeny may become polygonal chondrocytes. The retention of the characteristic chondrogenic phenotype in vitro is favored by pruning the dedifferentiated chondrocytes which arise in these cultures. Dedifferentiated chondrocytes interfere with the deposition and synthesis of chondroitin sulfate by neighboring functional chondrocytes. Possible mechanisms are proposed to explain this type of cell-cell or cell exudate interference. If the progeny of a single, genetically programmed chondrocyte may or may not synthesize chondroitin sulfate, then extragenic sites in the cytoplasm or cell surface must influence the decision as to which cluster of "luxur" molecules the cell will synthesize.

The in Vitro Effect of Insulin on Collagen Synthesis in Embryonic Chick Tibia

1973 ◽  
Vol 142 (4) ◽  
pp. 1152-1154 ◽  
Author(s):  
J. S. Perlish ◽  
R. I. Bashey ◽  
R. Fleischmajer
Keyword(s):  
Collagen Synthesis ◽  
Embryonic Chick ◽  
Chick Tibia ◽  
Vitro Effect

scholarly journals Production of a Monoclonal Antibody by In Vitro Immunization That Recognizes a Native Chondroitin Sulfate Epitope in the Embryonic Chick Limb and Heart

1997 ◽  
Vol 45 (11) ◽  
pp. 1567-1581 ◽  
Author(s):  
Anthony A. Capehart ◽  
Matthew M. Wienecke ◽  
Gregory T. Kitten ◽  
Michael Solursh ◽  
Edward L. Krug
Keyword(s):  
Monoclonal Antibody ◽  
Chondroitin Sulfate ◽  
Immunohistochemical Staining ◽  
High Density ◽  
Cartilage Tissue ◽  
Micromass Culture ◽  
Embryonic Chick ◽  
In Vitro Immunization ◽  
Limb Mesenchyme

We report the production of a monoclonal antibody (d1C4) by in vitro immunization that has immunoreactivity with a native chondroitin sulfate epitope in embryonic chick limb and heart. Murine lymphocytes were stimulated by direct exposure to unfixed, unsolubilized precartilage mesenchymal aggregates in high-density micromass culture derived from Stage 22–23 chick limb buds. Specificity of d1C4 reactivity was demonstrated by sensitivity of immunohistochemical staining to pretreatment with chondroitinase ABC or AC, preferential immunoreactivity with chondroitin-6-sulfate glycosaminoglycan (CS-C GAG) in ELISA, and competition of immunohistochemical staining with CS-C GAG. Immunohistochemical analysis of the expression of the d1C4 epitope revealed a striking localization of immunoreactivity in the extracellular matrix (ECM) of precartilage aggregates of chick limb mesenchyme in high-density micromass culture by 16 hr and the prechondrogenic limb core at Stage 23 in vivo. Immunoreactivity in both cultured limb mesenchyme and the embryonic limb continued through differentiation of prechondrogenic condensations into cartilage tissue. In the developing chick heart, d1C4 staining was found throughout the ECM of atrioventricular cushion tissue by Stage 25, but was localized to mesenchyme adjacent to the myocardium in the outflow tract cushions. There was an abrupt demarcation between d1C4-reactive intracardiac mesenchyme and unreactive extracardiac mesenchyme of the dorsal mesocardium in the Stage 22 embryo. This study demonstrates the efficacy of in vitro immunization of lymphocytes for the production of MAbs to native ECM constituents, such as CS-GAGs. Immunohistochemical data utilizing d1C4 suggest that CS-GAGs bearing this epitope may be important in early morphogenetic events leading to cartilage differentiation in the limb and valvuloseptal morphogenesis in the heart. (J Histochem Cytochem 45:1567–1581, 1997)

The in vitro cell fusion of embryonic chick muscle without DNA synthesis

1974 ◽  
Vol 36 (2) ◽  
pp. 225-235 ◽  
Author(s):  
Jeffrey L. Doering ◽  
Donald A. Fischman
Keyword(s):  
Dna Synthesis ◽  
Cell Fusion ◽  
Embryonic Chick

Novel Therapeutic Strategy for Restenosis Using Ribozyme Oligonucleotides Against Transforming Growth Factor-β

Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 728-729
Author(s):  
Kei Yamamoto ◽  
Ryuichi Morishita ◽  
Naruya Tomita ◽  
Hironori Nakagami ◽  
Motokuni Aoki ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Mrna Expression ◽  
Collagen Synthesis ◽  
Transforming Growth Factor ◽  
In Vitro Study ◽  
Transforming Growth Factor Β ◽  
Cell Nuclei ◽  
Neointimal Formation

P197 Background Since the mechanisms of atherosclerosis or restenosis after angioplasty have been postulated to involve an increase in TGF-β, a selective decrease in TGF-βmay have therapeutic value. Thus, we employed the ribozyme a unique class of RNA molecules that not only store information but also process catalytic activity, to selectively inhibit TGF-βexpression. Methods & Results We constructed ribozyme oligonucleotides targeted to the sequence of TGF-βgene which shows 100 % homology among human, rat and mouse. The specificity of ribozyme against TGF-βgene was confirmed by selective inhibition of TGF-βmRNA in cultured human VSMC as well as balloon-injured blood vessels in vivo. In vitro study Transfection of TGF-βribozyme ON into human VSMC by cationic liposome significantly decreased mRNA expression and protein of TGF-βinduced by Ang II as compared to control In vivo study Transfection of FITC-labeled ribozyme ON resulted in fluorescence in the balloon-injured vessels at 1 day after transfection. The fluorescence was localized primarily in cell nuclei , and persisted for up to 2 weeks after transfection.And then,transfection of TGF-βribozyme ON into rat cartid balloon injry model significantly decreased mRNA expression of TGF-βinduced by balloon injry ,and have significant inhibitory effects on neointimal formation after vascular injury(P<0.01), whereas DNA-based control oligonucleotides and mismatched ribozyme oligonucleotides did not have any inhibitory effect on neointimal formation. Inhibition of neointimal formation was accompanied by 1) a reduction in collagen synthesis and mRNA expression of collagen I and III, and 2) a significant decrease in DNA synthesis as assessed by PCNA staining. Conclusion Overall, this study provides the first evidence that selective blockade of TGF-βby ribozyme resulted in inhibition of neointimal formation, accompanied by a reduction in collagen synthesis and DNA synthesis in a rat model. We anticipate that ribozyme ON pharmacokinetics will facilitate the potential clinical utility of the ribozyme strategy.

scholarly journals Preservation of Radiation Recovery Factor in Frozen Marrow

Blood ◽  
1957 ◽  
Vol 12 (12) ◽  
pp. 1096-1100 ◽  
Author(s):  
JOSEPH W. FERREBEE ◽  
DANIEL BILLEN ◽  
IRENE M. URSO ◽  
WAN CHING LU ◽  
E. DONNALL THOMAS ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Recovery Factor ◽  
Cell Multiplication

Abstract Injection of mouse marrow preserved in glycerol at -80 C. for six weeks has been shown to be quantitatively similar to injections of fresh marrow in inducing recovery in mice after lethal radiation. The effect of the preservation procedure on subsequent rates of DNA synthesis has been determined in vitro for both preserved human marrow and preserved mouse marrow. Since DNA synthesis is a satisfactory measure of rates of cell multiplication and since preservation is shown to affect DNA synthesis in human marrow to a lesser degree than in mouse marrow, it may be concluded that the procedure used (-80 C. plus 15% glycerol) is satisfactory for the maintenance of viability in human marrow.

scholarly journals Collagen Synthesis in Tenocytes, Ligament Cells and Chondrocytes Exposed to a Combination of Glucosamine HCl and Chondroitin Sulfate

2007 ◽  
Vol 4 (2) ◽  
pp. 219-224 ◽  
Author(s):  
Louis Lippiello
Keyword(s):  
Chondroitin Sulfate ◽  
Collagen Synthesis ◽  
Tissue Response ◽  
Synthetic Activity ◽  
Specific Marker ◽  
Sensitive Material ◽  
Joint Tissue ◽  
Tissue Trauma

Clinical testing of the nutraceuticals glucosamine (glcN) and chondroitin sulfate (CS) has shown efficacy in providing relief from symptoms in osteoarthritic patients.In vitroandin vivostudies support existence of a synergistic relationship upregulating synthetic activity in chondrocytes. A combination of glcN and CS may also be useful as adjunct therapy in sports-related injuries if similar upregulation of collagen synthesis is elicited in accessory ligament and tendon joint tissue. Collagen and non-collagenous protein (NCP) synthesis in cultures of bovine tenocytes, ligament cells and chondrocytes exposed to glcN + CS were assayed by uptake of radiolabeled proline into collagenase-sensitive material. Assay of radiolabel in hydroxyproline (a specific marker for collagen synthesis) following HPLC isolation confirmed the specificity of the metabolic effect. Synthesis of total collagenase-sensitive material was maximally upregulated at physiologically obtainable doses of glcN + CS. Tissue response followed the sequence ligament cells (+69%) > chondrocytes (+56%) > tenocytes (+22%). Labeled hydroxyproline increased by 132% in ligament cells, 27% in tenocytes and 49% in epitendon cells after a 48 h exposure to 5 μg ml−1glcN + 4 μg ml−1CS. Low dose combinations of glcN and CS effectively stimulatein vitrocollagen and NCP synthesis by ligament cells, tenocytes and chondrocytes. Hence, therapeutic use following accessory joint tissue trauma may help augment repair processes.

scholarly journals GROWTH CONTROL OF DIFFERENTIATED FETAL RAT HEPATOCYTES IN PRIMARY MONOLAYER CULTURE

1974 ◽  
Vol 62 (3) ◽  
pp. 767-779 ◽  
Author(s):  
H. L. Leffert
Keyword(s):  
Dna Synthesis ◽  
Cell Attachment ◽  
Gel Filtration ◽  
Rat Hepatocytes ◽  
Hepatocyte Proliferation ◽  
Cell Multiplication ◽  
Adult Rats ◽  
Fetal Rat ◽  
Fraction I

Dialyzed fetal bovine serum contains two distinct growth-controlling macromolecular fractions: one stimulates and the other inhibits proliferation of primary cultured differentiated fetal rat hepatocytes. Both fractions are precipitated by ammonium sulfate (50% saturation, pH 7.4, 4°C). Serum fraction I (SFI, mol wt ≥ 120,000 daltons estimated by gel filtration with Bio-gel P200) appears to contain at least two factors which function, respectively, to initiate DNA synthesis (activity pH 4–10 stable) and to increase the rate at which initiated cells traverse the cell cycle (activity pH 4 and pH 10 labile). Intraperitoneal injections of SFI into adult rats have produced detectable stimulation of hepatic but not renal DNA synthesis. Serum fraction II (SFII, mol wt 40,000–80,000 daltons) suppresses in vitro incorporation of CH3-[3H]thymidine into DNA under conditions which diminish neither cell viability nor cell attachment. Mixing experiments indicate that SFI and SFII mutually antagonize each other with respect to DNA synthesis and cell multiplication. Thus, both the relative and absolute serum levels of multiple factors control in vitro fetal hepatocyte proliferation.

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