1.
Kopakkala-Tani, Milla, et al.
(författare)
Ultrasound stimulates proteoglycan synthesis in bovine primary chondrocytes.
2006
Ingår i: Biorheology. - : IOS Press. - 0006-355X .- 1878-5034. ; 43:3-4, s. 271-282
Tidskriftsartikel (refereegranskat) abstract
Mechanical forces can stimulate the production of extracellular matrix molecules. We tested the efficacy of ultrasound to increase proteoglycan synthesis in bovine primary chondrocytes. The ultrasound-induced temperature rise was measured and its contribution to the synthesis was investigated using bare heat stimulus. Chondrocytes from five cellular isolations were exposed in triplicate to ultrasound (1 MHz, duty cycle 20%, pulse repetition frequency 1 kHz) at average intensity of 580 mW/cm2 for 10 minutes daily for 1-5 days. Temperature evolution was recorded during the sonication and corresponding temperature history was created using a controllable water bath. This exposure profile was used in 10-minute-long heat treatments of chondrocytes. Heat shock protein 70 (Hsp70) levels after one-time treatment to ultrasound and heat was analyzed by Western blotting, and proteoglycan synthesis was evaluated by 35S-sulfate incorporation. Ultrasound treatment did not induce Hsp70, while heat treatment caused a slight heat stress response. Proteoglycan synthesis was increased approximately 2-fold after 3-4 daily ultrasound stimulations, and remained at that level until day 5 in responsive cell isolates. However, chondrocytes from one donor cell isolation out of five remained non-responsive. Heat treatment alone did not increase proteoglycan synthesis. In conclusion, our study confirms that pulsed ultrasound stimulation can induce proteoglycan synthesis in chondrocytes.
2.
Lammi, Mikko, 1961-, et al.
(författare)
Proteomic analysis of cartilage- and bone-associated samples.
2006
Ingår i: Electrophoresis. - : John Wiley & Sons. - 0173-0835 .- 1522-2683. ; 27:13, s. 2687-2701
Forskningsöversikt (refereegranskat) abstract
The skeleton of the human body is built of cartilage and bone, which are tissues that contain extensive amounts of extracellular matrix (ECM). In bone, inorganic mineral hydroxyapatite forms 50-70% of the whole weight of the tissue. Although the organic matrix of bone consists of numerous proteins, 90% of it is composed of type I collagen. In cartilage, ECM forms a major fraction of the tissue, type II collagen and aggrecans being the most abundant macromolecules. It is obvious that the high content of ECM components causes analytical problems in the proteomic analysis of cartilage and bone, analogous to those in the analysis of low-abundance proteins present in serum. The massive contents of carbohydrates present in cartilage proteoglycans, and hydroxyapatite in bone, further complicate the situation. However, the development of proteomic tools makes them more and more tempting also for research of musculoskeletal tissues. Application of proteomic techniques to the research of chondrocytes, osteoblasts, osteocytes, and osteoclasts in cell cultures can immediately benefit from the present knowledge. Here we make an overview to previous proteomic research of cartilage- and bone-associated samples and evaluate the future prospects of applying proteomic techniques to investigate key events, such as cellular signal transduction, in cartilage- and bone-derived cells.
3.
Leskinen, Jarkko, et al.
(författare)
Genome-wide microarray analysis of MG-63 osteoblastic cells exposed to ultrasound.
2008
Ingår i: Biorheology. - : IOS Press. - 0006-355X .- 1878-5034. ; 45:3-4, s. 345-354
Tidskriftsartikel (refereegranskat) abstract
It is well documented that low intensity pulsed ultrasound can be clinically used to accelerate bone fracture healing. Additionally, in vitro studies have shown that ultrasound can, for instance, increase mineralization, collagen production and alkaline phosphatase activity in osteoblasts. Despite the extensive research on the subject, the exact mechanism of ultrasound effect on bone cell gene regulation has not yet been deduced. In this study, we made an effort to reveal the features of genome-wide transcriptional response of osteoblast-type cells to ultrasound. MG-63 osteoblastic cell transcriptome was analyzed with whole genome microarray either 6 or 24 h after 30 min long exposure to 1.035 MHz pulsed ultrasound with three different acoustic pressures. Special attention was paid to the experimental design to minimize thermal effects and unwanted reflections of ultrasound. Microarray analysis suggested that ultrasound affects the genes involved with cellular membranes, and regulation of transcription as well. Several plasma membrane solute carriers were also regulated by ultrasound. It also changed the transcript level of several transcription factors belonging to the zinc finger proteins. However, ultrasound did not clearly promote genes involved with osteoblast differentiation.
4.
Myllymaa, Katja, et al.
(författare)
Interactions between Saos-2 cells and microtextured amorphous diamond or amorphous diamond hybrid coated surfaces with different wettability properties
2009
Ingår i: Diamond and Related Materials. - : Elsevier. - 0925-9635. ; 18:10, s. 1294-1300
Tidskriftsartikel (refereegranskat) abstract
Amorphous diamond (AD) has been shown to be a potential coating material for biomedical devices, such as hip prostheses. In the current study, we have investigated the adhesion and contact guidance of human primary osteogenic sarcoma cells (Saos-2) on AD, AD-titanium-hybrid (AD-Ti-h) and AD-polydimethylsiloxane-hybrid (AD-PDMS-h) with different water contact angles i.e. 72.4°, 81.9° and 100.0°. Microtextured arrays were fabricated onto silicon wafers by using ultraviolet lithography and ultra short pulsed laser deposition (USPLD) of AD coatings. The surface energy parameters were calculated in order to understand the influence of Ti or PDMS on wettability of AD. Saos-2 cells were cultured on the arrays for 24 and 48 h. Environmental scanning electron microscope (ESEM), confocal laser scanning microscopy and MTT assays were used to analyze cell attachment. The results suggest that AD and its hybrids are good coating material candidates with respect to their interactions with osteoblast-like cells. The efficiency of microtexturing in contact guidance was also demonstrated. MTT staining revealed that AD-PDMS-h had the lowest proliferation rate of osteoblast-like cells compared to AD (p < 0.01) or AD-Ti-h (p < 0.05). Pure AD evoked the highest proliferation rate of cells, though it was not significantly different from AD-Ti-h coating.
5.
Myllymaa, Sami, et al.
(författare)
Surface characterization and in vitro biocompatibility assessment of photosensitive polyimide films.
2010
Ingår i: Colloids and Surfaces B. - : Elsevier. - 0927-7765 .- 1873-4367. ; 76:2, s. 505-511
Tidskriftsartikel (refereegranskat) abstract
Polyimide (PI) is a commonly used polymer in microelectronics. Recently, numerous PI-based flexible neural interfaces have been developed for reducing mechanical mismatch between rigid implant and soft neural tissue. Most approaches employ non-photosensitive PI, which has been proven earlier to be biocompatible. However, photosensitive polyimide (PSPI) would simplify device fabrication remarkably, but its biocompatibility has been only sparsely reported. In this study, cytotoxicity of spin-coated PSPI (HD Microsystems PI-2771) and conventional PI (HD Microsystems PI-2525) films were evaluated in vitro using BHK-21 fibroblasts according to the ISO-10993-5 standard. PSPIs were tested as cured at a temperature of 200 degrees C (PI-2771-200) and 350 degrees C (PI-2771-350). The PI film surfaces were characterized in terms of their roughness, energy and zeta potential which are hypothesized to affect cell-material interactions. The values of the total surface free energy (SFE), and its polar and dispersive component, were significantly (p<0.001) greater for the PI-2525 film (SFE: 47.3 mJ/m2) than for the PI-2771-200 (25.6 mJ/m2) or PI-2771-350 films (26.2 mJ/m2). The curing temperature of the PI-2771 had a significant effect on the zeta potential values (p<0.001), but not on surface energy (p=0.091) or roughness (p=0.717). The results from the MTS proliferation assays and live/dead staining revealed that PSPI is almost as non-cytotoxic as conventional PI and polyethylene (negative control). The morphology and spreading of BHK-21 cells were similar on all the PI materials tested. In conclusion, PSPI seems to be a promising biocompatible material, while further studies in vitro and in vivo are needed to clarify the long-term effects.
6.
Olkku, Anu, et al.
(författare)
Ultrasound-induced activation of Wnt signaling in human MG-63 osteoblastic cells.
2010
Ingår i: Bone. - : Elsevier BV. - 8756-3282 .- 1873-2763. ; 47:2, s. 320-330
Tidskriftsartikel (refereegranskat) abstract
The benefit from an ultrasound (US) exposure for fracture healing has been clearly shown. However, the molecular mechanisms behind this effect are not fully known. Recently, the canonical Wnt signaling pathway has been recognized as one of the essential regulators of osteoblastogenesis and bone mass, and thereby considered crucial for bone health. Mechanical loading and fluid shear stress have been reported to activate the canonical Wnt signaling pathway in bone cells, but previous reports on the effects of therapeutic US on Wnt signaling in general or in bone, in particular, have not been published yet. Therefore, activation of Wnt signaling pathway was assayed in human osteoblastic cells, and indeed, this pathway was found to be activated in MG-63 cells through the phosphoinositol 3-kinase/Akt (PI3K/Akt) and mTOR cascades following a single 10 min US exposure (2 W, 1.035 MHz). In addition to the reporter assay results, the Wnt pathway activation was also observed as nuclear localization of beta-catenin. Wnt activation showed also temperature dependence at elevated temperatures, and the expression of canonical Wnt ligands was induced under the thermal exposures. However, existence of a specific, non-thermal US component was evident as well, perhaps evidence of a potential dual action of therapeutic US on bone. Neither US nor heat exposures affected cell viability in our experiments. In summary, this is the first study to report that Wnt signaling cascade, important for osteoblast function and bone health, is one of the pathways activated by therapeutic US as well as by hyperthermia in human osteoblastic cells. Our results provide evidence for the potential molecular mechanisms behind the beneficial effects of US on fracture healing. Combinations of US, heat, and possible pharmacological treatment could provide useful flexibility for clinical cases in treating various bone disorders.
7.
Rieppo, Lassi, et al.
(författare)
Infrared microspectroscopic determination of collagen cross-links in articular cartilage
2017
Ingår i: Journal of Biomedical Optics. - : SPIE - International Society for Optical Engineering. - 1083-3668 .- 1560-2281. ; 22:3
Tidskriftsartikel (refereegranskat) abstract
Collagen forms an organized network in articular cartilage to give tensile stiffness to the tissue. Due to its long half-life, collagen is susceptible to cross-links caused by advanced glycation end-products. The current standard method for determination of cross-link concentrations in tissues is the destructive high-performance liquid chromatography (HPLC). The aim of this study was to analyze the cross-link concentrations nondestructively from standard unstained histological articular cartilage sections by using Fourier transform infrared (FTIR) microspectroscopy. Half of the bovine articular cartilage samples (n=27) were treated with threose to increase the collagen cross-linking while the other half (n=27) served as a control group. Partial least squares (PLS) regression with variable selection algorithms was used to predict the cross-link concentrations from the measured average FTIR spectra of the samples, and HPLC was used as the reference method for cross-link concentrations. The correlation coefficients between the PLS regression models and the biochemical reference values were r=0.84 (p<0.001), r=0.87 (p<0.001) and r=0.92 (p<0.001) for hydroxylysyl pyridinoline (HP), lysyl pyridinoline (LP), and pentosidine (Pent) cross-links, respectively. The study demonstrated that FTIR microspectroscopy is a feasible method for investigating cross-link concentrations in articular cartilage.
8.
Rieppo, Lassi, et al.
(författare)
Quantitative analysis of spatial proteoglycan content in articular cartilage with Fourier transform infrared imaging spectroscopy : Critical evaluation of analysis methods and specificity of the parameters.
2010
Ingår i: Microscopy research and technique (Print). - : John Wiley & Sons. - 1059-910X .- 1097-0029. ; 73:5, s. 503-512
Tidskriftsartikel (refereegranskat) abstract
OBJECTIVE: To evaluate the specificity of the current Fourier transform infrared imaging spectroscopy (FT-IRIS) methods for the determination of depthwise proteoglycan (PG) content in articular cartilage (AC). In addition, curve fitting was applied to study whether the specificity of FT-IRIS parameters for PG determination could be improved.METHODS: Two sample groups from the steer AC were prepared for the study (n = 8 samples/group). In the first group, chondroitinase ABC enzyme was used to degrade the PGs from the superficial cartilage, while the samples in the second group served as the controls. Samples were examined with FT-IRIS and analyzed using previously reported direct absorption spectrum techniques and multivariate methods and, in comparison, by curve fitting. Safranin O-stained sections were measured with digital densitometry to obtain a reference for depthwise PG distribution.RESULTS: Carbohydrate region-based absorption spectrum methods showed a statistically weaker correlation with the PG reference distributions than the results of the curve fitting (subpeak located approximately at 1,060 cm(-1)). Furthermore, the shape of the depthwise profiles obtained using the curve fitting was more similar to the reference profiles than with the direct absorption spectrum analysis.CONCLUSIONS: Results suggest that the current FT-IRIS methods for PG analysis lack the specificity for quantitative measurement of PGs in AC. The curve fitting approach demonstrated that it is possible to improve the specificity of the PG analysis. However, the findings of the present study suggest that further development of the FT-IRIS analysis techniques is still needed.
9.
Sierpowska, Joanna, et al.
(författare)
Effect of human trabecular bone composition on its electrical properties.
2007
Ingår i: Medical Engineering and Physics. - : Elsevier. - 1350-4533 .- 1873-4030. ; 29:8, s. 845-852
Tidskriftsartikel (refereegranskat) abstract
Mechanical properties of bone are determined not only by bone mineral density (BMD), but also by tissue trabecular structure and organic composition. Impedance spectroscopy has shown potential to diagnose trabecular bone BMD and strength, however, the relationships between organic composition and electrical and dielectric properties have not been systematically investigated. To investigate these issues organic composition of 26 human trabecular bone samples harvested from the distal femur and proximal tibia was determined and compared with relative permittivity, loss factor, conductivity, phase angle, specific impedance and dissipation factor measured at wide range (50 Hz to 5 MHz) of frequencies. A strong linear correlation was found between the relative permittivity at 1.2 MHz and trabecular bone fat content (r = -0.85, p<0.01, n=26). On the other hand, relative permittivity measured at 200 Hz served as a good predictor of water content (r = 0.83). Phase angle, specific impedance and especially conductivity were strongly related to the trabecular bone dry density and water content (|r| > or = 0.69). Variation in bone tissue collagen content was strongly related to the relative permittivity measured at 1.2 MHz (r = 0.64), but only moderately to other parameters. Glycosaminoglycan content showed no significant relations with any investigated electrical parameters. The present study indicates that if the trabecular bone composition is known, the relationships presented in this study could facilitate calculation of current field distribution, e.g. during electrical stimulation of osteogenesis. On the other hand, our results suggest that permittivity measured at low (<1 kHz) or high (>100 kHz) frequencies could be used, e.g. during implant surgery, for prediction of trabecular bone water or fat contents, respectively.
10.
Wang, Sen, et al.
(författare)
Roles of glycoprotein glycosylation in the pathogenesis of an endemic osteoarthritis, Kashin–Beck disease, and effectiveness evaluation of sodium hyaluronate treatment
2020
Ingår i: Turkish Journal of Medical Sciences. - : TÜBİTAK (the Scientific and Technological Research Council of Turkey). - 1300-0144 .- 1303-6165. ; 50:4, s. 1028-1037
Tidskriftsartikel (refereegranskat) abstract
Background/aim: We aimed to explore the roles of glycoprotein glycosylation in the pathogenesis of Kashin–Beck disease (KBD), and evaluated the effectiveness of sodium hyaluronate treatment.Materials and methods: Blood and saliva were collected from KBD patients before and after the injection of sodium hyaluronate. Normal healthy subjects were included as controls. Saliva and serum lectin microarrays and saliva and serum microarray verifications were used to screen and confirm the differences in lectin levels among the three groups.Results: In saliva lectin microarray, bindings to Sophora japonica agglutinin (SJA), Griffonia (Bandeiraea) simplicifolia lectin I (GSL-I), Euonymus europaeus lectin (EEL), Maackia amurensis lectin II (MAL-II), Sambucus nigra lectin (SNA), Hippeastrum hybrid lectin (HHL), and Aleuria aurantia lectin (AAL) were higher in the untreated KBD patients than in the control group. Increased levels of HHL, MAL-II, and GSL-I in the untreated KBD patients discriminated them in particular from the treated ones. Jacalin was lower in the untreated KBD patients compared to the treated KBD and control groups. In serum lectin microarray, HHL and peanut agglutinin (PNA) were increased in the untreated KBD group in comparison to the control one. AAL, Phaseolus vulgaris agglutinin (E+L) (PHA- E+L), and Psophocarpus tetragonolobus lectin I (PTL-I) were lower in the untreated KBD patients compared to the treated KBD and control groups. Hyaluronate treatment appeared to normalize SNA, AAL, and MAL-II levels in saliva, and HHL, PNA, AAL, PTL-I, and PHA-E+L levels in serum. Saliva reversed microarray verification confirmed significant differences between the groups in SNA and Jacalin, in particular for GSL-I levels, while serum reversed microarray verification indicated that HHL, PNA, and AAL levels returned to normal levels after the hyaluronate treatment. Lectin blot confirmed significant differences in HHL, AAL, and Jacalin in saliva, and HHL, PNA, PHA-E+L, and AAL in serum.Conclusion: HHL in saliva and serum may be a valuable diagnostic biomarker of KBD, and it may be used as follow-up for the hyaluronate treatment.
