Alterations in hyaluronan synthesis during developing joint                cavitation.

Pitsillides, Andrew A.; Archer, Charles W.; Prehm, Peter; Bayliss, Michael T.; Edwards, J. C. W.

doi:10.1177/43.3.7868856

Cited by 86 publications

(79 citation statements)

References 24 publications

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“…Chicks were killed at stage 40 by decapitation (Animal Scientific Procedures act 1986). Limbs were snap-chilled in n-hexane (low in aromatic hydrocarbons, VWR International) maintained below Ϫ70°C, and cryostat sections (10 m) were prepared (4).…”

Section: Methodsmentioning

confidence: 99%

“…Controls included omission of primary antibody and replacement of primary antibody with appropriate species-matched normal sera. Alkaline phosphatase activity was disclosed using a filtered solution containing naphthol-AS-MX phosphate, levamisole, and Fast Red TR salt (4). UDPGD activity was assayed using a quantitative cytochemical method as described previously (4).…”

Section: Methodsmentioning

confidence: 99%

“…Microdensitometry of ERK Expression-Serial control and immobilized limb sections were labeled for p-ERK1/2, total ERK1, or ERK2 using alkaline phosphatase-conjugated secondary antibody (see above), and expression per cell was measured with a Vickers M85A scanning and integrating microdensitometer at 535 nm (4). Individual cells at cartilaginous epiphyses (zone 10 cells deep) and presumptive articular surfaces were measured; at least 15 cells at identical sites in each of at least 2 sections per joint from at least 3 chicks were evaluated.…”

Section: Methodsmentioning

confidence: 99%

“…An example of such localized enrichment in HA occurs during the formation of articular joints, where separation of opposed skeletal elements requires exact spatial control (3,4). Earliest commitment of cells to this fate is evident in the blastemal mesenchyme, between expanding cartilaginous elements, where intervening presumptive joint interzones persist in zones exhibiting restricted chondrogenesis (5)(6)(7).…”

mentioning

confidence: 99%

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Selective Activation of the MEK-ERK Pathway Is Regulated by Mechanical Stimuli in Forming Joints and Promotes Pericellular Matrix Formation

Bastow

Lamb

Lewthwaite

et al. 2005

Journal of Biological Chemistry

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It is well established that local modification of extracellular matrix (ECM) hyaluronan composition is vital in the regulation of cell behavior. Indeed, the formation of articulating chick joint cavities, which requires mechanical stimuli derived from skeletal movement, is dependent upon the accumulation of an ECM rich in hyaluronan (HA). However, the mechanisms responsible for such precise mechano-dependent regulation of cell behavior and the formation of a HA-rich ECM remain undefined. Here we show that extracellular-regulated kinase 1/2 (ERK1/2) is selectively activated in cells at sites of cavity formation and activity diminished by in ovo immobilization that induces cartilaginous fusion across presumptive joint interzones. In vitro analyses offer mechanistic support for the role of mechanical stimuli in promoting a MEK-dependent activation of ERK1/2. In addition, our direct regulation of ERK1/2 phosphorylation status via modulation of its up-stream "classical cascade" activator either pharmacologically or by transfection with dominant negative or constitutively active Mek confirms the essential role for ERK1/2 activation in the elaboration of HA-rich pericellular matrices. Together, our findings demonstrate that the MEK-ERK pathway, regulated by mechanical stimuli, controls HA-rich matrix assembly. The precision of ERK1/2 activation selectively distinguishing cells at the joint line suggests that it directly contributes to the loss of tissue cohesion essential for generating HA-rich cavities between joint elements during their development.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Selective Activation of the MEK-ERK Pathway Is Regulated by Mechanical Stimuli in Forming Joints and Promotes Pericellular Matrix Formation

Bastow

Lamb

Lewthwaite

et al. 2005

Journal of Biological Chemistry

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“…This suggests that HA is indeed a major constituent of developing joint spaces, and our assessment of UDPGD activity in tissue sections indicates that cells directly bordering such cavities possess increased UDPGD activity per cell when compared to cells in the neighbouring epiphyseal cartilage elements. 18,19 This view was recently strengthened by our the of antibodies raised 236 a. a. pitsillides against the N-terminal UDPGD protein that also exhibit a selective labelling of cells at the presumptive line of joint formation in embryonic limbs. We have also shown that these cells exhibit elevated levels of CD44 expression and appear to actively bind HA via a moesin-mediated (CD44-associated actincapping protein) interaction with polymerised cytoskeletal actin.…”

Section: Selective Ha Synthetic Ha-binding Characteristics In Joint mentioning

confidence: 97%

Identifying and characterizing the joint cavity‐forming cell

Pitsillides

2003

Cell Biochemistry & Function

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For many years, a large body of circumstantial evidence supported the notion that the synovial membrane produced the hyaluronan-rich synovial fluid. A quantitative cytochemical technique for uridine-diphospho glucose dehydrogenase (UDPGD) activity established that fibroblast-like cells on the intimal surface of the synovial lining made a specific contribution to maintaining these glycosaminoglycan levels. Our studies have aimed to determine the mechanisms that control the attainment and persistence of this differentiated phenotype, and have recently focused on their appearance during joint cavity development in the embryonic limb; a process that is dependent upon skeletal movement. These in situ micro-biochemical studies have shown that cells bordering the presumptive joint cavity exhibit raised UDPGD activity, are associated with a matrix rich in hyaluronan and show immobilization-induced loss in such characteristics. Together with complimentary studies in adult joints, this suggests that mechanical stimuli promote the acquisition of this joint line-forming phenotype. For this reason our studies have attempted to identify the 'up-stream' mechano-dependent factors that control these events. Endothelial cells respond to mechanical stimuli by activating, via phosphorylation, mitogen activated protein kinase/extracellular signal-regulated kinase (MAPkinase/ERK). Using phospho-specific anti-ERK-1/2 antibodies we have shown that immunolabelling of developing limbs shows a clear joint line-selective activation during cavitation, with little if any labelling within neighbouring elements, and that this is abolished in immobilized limbs. In an attempt to facilitate the final mechanistic deciphering of these responses we have used an in vitro-based approach and found by Western blotting that active ERK-1/2 expression was increased in cultured articular surface cells following application of dynamic mechanical strain. Intriguingly, the use of a selective inhibitor (PD98059) of ERK activation by its classical activating kinase, Mek, to restrict such strain-induced increases, produced an enhanced strain-related increase in UDPGD mRNA expression. This suggests that mechano-dependent ERK activation serves a feedback regulatory role during differentiation of these cells. Whilst it is clear that these in vitro experiments serve a useful function, it is clear that they generally take little regard of the influence that might be provided by cell-cell and cell-matrix interactions within the developing limb's complex and dynamic environment and architecture. It is therefore imperative that we attempt to bridge the gap between the cell biology of such phenomena on the one hand, and the morphological approach to this same problem on the other.

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Effects of hyaluronan viscous materials on cell membrane electrical properties

Santini

Cametti

Formisano

et al. 1998

J. Biomed. Mater. Res.

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Hyaluronan [hyaluronic acid (HA)] has been implicated in various cellular processes such as proliferation, adhesion, migration, and differentiation. The secondary and tertiary structures of HA give it very important and unique viscoelastic properties. HA-composed materials are currently used intraocularly during ophthalmological surgery to facilitate surgical procedures and prevent tissue damage. To examine the effects of three viscous biomaterials composed of hyaluronan (Healon, IAL, and Biolon) used in ophthalmological surgery, the membrane electrical properties of the erythroleukemic K562 cell line exposed to these materials were investigated. Membrane conductivity, membrane permittivity, and the conductivity of the cytosol were evaluated using dielectric relaxation measurements in the radiofrequency range and fitting the experimental results to the general equations of the Maxwell-Wagner effect. The results demonstrate that while membrane permittivity and the conductivity of the cytosol are not significantly altered, the membrane conductivity of K562 cells exposed to all three biomaterials increases substantially and in a time-dependent manner with respect to untreated cells. These observations seem to indicate that hyaluronan perturbs ionic transport while it does not vary the type, quantity, or distribution of membrane components. In addition, the variations induced by these substances on the cell membrane are not dependent upon the molecular weight or on the biological origin of hyaluronan. These results may aid in elucidating the mechanisms involved in hyaluronan/cell membrane interaction and thus may provide a deeper understanding of the complications related to their use in ophthalmological surgery.

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Alterations in hyaluronan synthesis during developing joint cavitation.

Cited by 86 publications

References 24 publications

Selective Activation of the MEK-ERK Pathway Is Regulated by Mechanical Stimuli in Forming Joints and Promotes Pericellular Matrix Formation

Selective Activation of the MEK-ERK Pathway Is Regulated by Mechanical Stimuli in Forming Joints and Promotes Pericellular Matrix Formation

Identifying and characterizing the joint cavity‐forming cell

Effects of hyaluronan viscous materials on cell membrane electrical properties

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