Changes in Ultrastructure and Cytoskeletal Aspects of  Human Normal and Osteoarthritic Chondrocytes Exposed  to Interleukin-1β and Cyclical Hydrostatic Pressure

Pascarelli, Nicola Antonio; Collodel, Giulia; Moretti, Elena; Cheleschi, Sara; Fioravanti, Antonella

doi:10.3390/ijms161125936

Cited by 34 publications

(42 citation statements)

References 56 publications

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“…In the cytoplasm of most cells of the inner region of AF, the varying size of destructive cavities and its location or the formation of very large vacuoles were located. Similar changes are observed in chondrocytes in the articular cartilage in osteoarthritis (Pascarelli et al, 2015). As was observed, some of these cells had an electron-dense outline around the cell membrane, which is possibly due to a violation of the forming of the matrix structure or the cell capsule formation and the death of mitochondria.…”

Section: Groupssupporting

confidence: 80%

Effect of Pb exposure on the cells and matrix of the intervertebral disc of rats

Maltseva

2017

Regul. Mech. Biosyst.

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Degenerative spine diseases are common throughout the world. There are many factors that lead to these diseases. One of these exogenous factors may be Pb exposure. Most of the fundamental investigations about the negative effects of the Pb exposure have investigated the impact of high doses of Pb, while Pb exposure in low concentrations has been insufficiently studied. The nutrition of the intervertebral disc is provided by the vessels that grow into the vertebral bodies and the paravertebral tissue. This suggests the possibility that Pb penetrates from the bone to the intervertebral disc together with nutrients. This article reports an experimental study which was performed in rats aged 1.5 months (n = 40). Rats in the experimental group received lead acetate solution (230 mg of Pb per1 literof distilled water) as drinking water and the animals in the control group received distilled water for 10 weeks. In the isolated intervertebral discs, the content of Pb was determined by X-ray fluorescence spectrometry. The effect of lead on the structural organization of the intervertebral disc was investigated by light microscopy. The ultrastructural features of cells and the matrix intervertebral disc were studied by transmission electron microscopy. In the young animals after Pb exposure, a significant increase was found in the content of Pb in the intervertebral disc tissue, of 4.6 times compared to the control group. The histological analysis showed degenerative changes in the annulus fibrosus (AF) of the intervertebral disc. In the outer region cracks and defibration of the lamellae were observed. Large isogenic groups were detected in the inner region of the intervertebral disc. A decrease in the height by 12.2% in the outer parts and by 10% in the central part of the intervertebral disc was recorded. Also a reduction in the width of the lamellae by 8% was shown. Cell density of the annulus fibrous decreased by 12% and in the gelatinous nucleus pulposus (NP) by 24.2%. Electron microscopic analysis of the inner region of the AF of the intervertebral disc showed chondrocytes with electron-dense mitochondria, vacuolization of the cytoplasm, fragmented nuclei and destructive cavities. The matrix of the lamellae of the AF had a diverse electron density, so areas with high electron density of various sizes were observed. Collagen fibrils of the AF had blurred outlines, sometimes the transverse striation disappeared or it was irregular, which can indicate the matrix mineralization and possibly the accumulation of Pb in these areas. In the NP, the most notochordal cells revealed the formation of myelin figures. The effect of Pb at low concentration results in its accumulation in the tissues of the intervertebral disc of rats and causes degenerative changes in the intervertebral disc structure, leading to the reduction in the height of the intervertebral disc, decrease in the width of the lamellae and in cell density, thereby violating both the structures of matrix and cells. Future investigations of the collagen content of intervertebral disc after Pb exposure are needed.

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Section: Groupssupporting

confidence: 80%

Effect of Pb exposure on the cells and matrix of the intervertebral disc of rats

Maltseva

2017

Regul. Mech. Biosyst.

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“…The specimens were sliced into ultra-thin sections, mounted on copper grids, and then stained with uranyl acetate and lead citrate38. The cells were grown on pronectin-coated Bioflex six-well culture plates and they were collected by scraping from the plates before fixing in cold Karnovsky fixative for TEM analysis.…”

Section: Methodsmentioning

confidence: 99%

Effects of mechanical stress on chondrocyte phenotype and chondrocyte extracellular matrix expression

Liu

Zhang

et al. 2016

Sci Rep

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Mechanical factors play a key role in regulating the development of cartilage degradation in osteoarthritis. This study aimed to identify the influence of mechanical stress in cartilage and chondrocytes. To explore the effects of mechanical stress on cartilage morphology, we observed cartilages in different regions by histological and microscopic examination. Nanoindentation was performed to assess cartilage biomechanics. To investigate the effects of mechanical stress on chondrocytes, cyclic tensile strain (CTS, 0.5 Hz, 10%) was applied to monolayer cultures of human articular chondrocytes by using Flexcell-5000. We quantified the mechanical properties of chondrocytes by atomic force microscopy. Chondrocytes were stained with Toluidine blue and Alcian blue after exposure to CTS. The expression of extracellular matrix (ECM) molecules was detected by qPCR and immunofluorescence analyses in chondrocytes after CTS. Our results demonstrated distinct morphologies and mechanical properties in different cartilage regions. In conclusion, mechanical stress can affect the chondrocyte phenotype, thereby altering the expression of chondrocyte ECM.

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“…The in vitro metabolic activities of chondrocytes to HCFs varied with the magnitude, frequency, and duration of loading. Pathological microenvironments could also be created by adding pro-inflammatory cytokines to investigate the effects of HCFs on the metabolic activities of chondrocytes in osteoarhritis [32]. In addition, caution should also be taken to extrapolate the current findings to the articular cartilage-derived chondrocytes due to the unique phenotype of condylar chondrocytes [33].…”

Section: Discussionmentioning

confidence: 99%

Hydrostatic Compress Force Enhances the Viability and Decreases the Apoptosis of Condylar Chondrocytes through Integrin-FAK-ERK/PI3K Pathway

Kou

Jin

et al. 2016

IJMS

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Reduced mechanical stimuli in many pathological cases, such as hemimastication and limited masticatory movements, can significantly affect the metabolic activity of mandibular condylar chondrocytes and the growth of mandibles. However, the molecular mechanisms for these phenomena remain unclear. In this study, we hypothesized that integrin-focal adhesion kinase (FAK)-ERK (extracellular signal–regulated kinase)/PI3K (phosphatidylinositol-3-kinase) signaling pathway mediated the cellular response of condylar chondrocytes to mechanical loading. Primary condylar chondrocytes were exposed to hydrostatic compressive forces (HCFs) of different magnitudes (0, 50, 100, 150, 200, and 250 kPa) for 2 h. We measured the viability, morphology, and apoptosis of the chondrocytes with different treatments as well as the gene, protein expression, and phosphorylation of mechanosensitivity-related molecules, such as integrin α2, integrin α5, integrin β1, FAK, ERK, and PI3K. HCFs could significantly increase the viability and surface area of condylar chondrocytes and decrease their apoptosis in a dose-dependent manner. HCF of 250 kPa resulted in a 1.51 ± 0.02-fold increase of cell viability and reduced the ratio of apoptotic cells from 18.10% ± 0.56% to 7.30% ± 1.43%. HCFs could significantly enhance the mRNA and protein expression of integrin α2, integrin α5, and integrin β1 in a dose-dependent manner, but not ERK1, ERK2, or PI3K. Instead, HCF could significantly increase phosphorylation levels of FAK, ERK1/2, and PI3K in a dose-dependent manner. Cilengitide, the potent integrin inhibitor, could dose-dependently block such effects of HCFs. HCFs enhances the viability and decreases the apoptosis of condylar chondrocytes through the integrin-FAK-ERK/PI3K pathway.

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Changes in Ultrastructure and Cytoskeletal Aspects of Human Normal and Osteoarthritic Chondrocytes Exposed to Interleukin-1β and Cyclical Hydrostatic Pressure

Cited by 34 publications

References 56 publications

Effect of Pb exposure on the cells and matrix of the intervertebral disc of rats

Effect of Pb exposure on the cells and matrix of the intervertebral disc of rats

Effects of mechanical stress on chondrocyte phenotype and chondrocyte extracellular matrix expression

Hydrostatic Compress Force Enhances the Viability and Decreases the Apoptosis of Condylar Chondrocytes through Integrin-FAK-ERK/PI3K Pathway

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