Mechanical Loading Reduces Chondrocyte Death After Single Impact Trauma: Porcine Knee Model

2012 ◽  
Author(s):  
Lauren L. Vernon ◽  
David G. Wilensky ◽  
Chong Wang ◽  
Lee D. Kaplan ◽  
Chun-Yuh C. Huang
Keyword(s):  
Articular Cartilage ◽  
Mechanical Loading ◽  
Motor Vehicle ◽  
Degenerative Changes ◽  
Matrix Composition ◽  
Single Impact ◽  
Knee Model ◽  
Chondrocyte Death ◽  
Porcine Knee

Osteoarthritis often results from degenerative changes induced by trauma such as joint impact injuries sustained during athletics, combat, or motor vehicle accidents. Articular cartilage, avascular in nature, relies of synovial nutrition [1] and lacks sufficient regenerative capabilities [2]. Acute cartilage injuries have been shown to induce cell death [3, 4, 5], leading to reduced chondrocyte density and degenerative changes to the cartilage matrix composition; over time the tissue becomes compromised and loses its ability to maintain and restore itself. It has been demonstrated, that mechanical loading can affect local perfusion and diffusion through the matrix thereby altering the flow of nutrients and metabolites [2, 6]. Furthermore, mechanical loading modulates the chondrocyte biosynthesis of extracellular matrix that is required in the cartilage repair process. In this study, a two part in-vitro porcine knee model was utilized to investigate articular cartilage response immediately following a single impact injury under cyclic mechanical loading conditions.

scholarly journals Wnt/β-catenin signaling contributes to articular cartilage homeostasis through lubricin induction in the superficial zone

2019 ◽  
Vol 21 (1) ◽  
Author(s):  
Fengjun Xuan ◽  
Fumiko Yano ◽  
Daisuke Mori ◽  
Ryota Chijimatsu ◽  
Yuji Maenohara ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Mechanical Loading ◽  
Cartilage Degeneration ◽  
Mrna Levels ◽  
Superficial Zone ◽  
Gain Of Function ◽  
Wnt Ligands ◽  
Signaling Activation ◽  
Signaling Activity

Abstract Background Both loss- and gain-of-function of Wnt/β-catenin signaling in chondrocytes result in exacerbation of osteoarthritis (OA). Here, we examined the activity and roles of Wnt/β-catenin signaling in the superficial zone (SFZ) of articular cartilage. Methods Wnt/β-catenin signaling activity was analyzed using TOPGAL mice. We generated Prg4-CreERT2;Ctnnb1fl/fl and Prg4-CreERT2;Ctnnb1-ex3fl/wt mice for loss- and gain-of-function, respectively, of Wnt/β-catenin signaling in the SFZ. Regulation of Prg4 expression by Wnt/β-catenin signaling was examined in vitro, as were upstream and downstream factors of Wnt/β-catenin signaling in SFZ cells. Results Wnt/β-catenin signaling activity, as determined by the TOPGAL reporter, was high specifically in the SFZ of mouse adult articular cartilage, where Prg4 is abundantly expressed. In SFZ-specific β-catenin-knockout mice, OA development was significantly accelerated, which was accompanied by decreased Prg4 expression and SFZ destruction. In contrast, Prg4 expression was enhanced and cartilage degeneration was suppressed in SFZ-specific β-catenin-stabilized mice. In primary SFZ cells, Prg4 expression was downregulated by β-catenin knockout, while it was upregulated by β-catenin stabilization by exon 3 deletion or treatment with CHIR99021. Among Wnt ligands, Wnt5a, Wnt5b, and Wnt9a were highly expressed in SFZ cells, and recombinant human WNT5A and WNT5B stimulated Prg4 expression. Mechanical loading upregulated expression of these ligands and further promoted Prg4 transcription. Moreover, mechanical loading and Wnt/β-catenin signaling activation increased mRNA levels of Creb1, a potent transcription factor for Prg4. Conclusions We demonstrated that Wnt/β-catenin signaling regulates Prg4 expression in the SFZ of mouse adult articular cartilage, which plays essential roles in the homeostasis of articular cartilage.

MUSCLE-INDUCED PATELLOFEMORAL JOINT LOADING RAPIDLY AFFECTS CARTILAGE mRNA LEVELS IN A SITE SPECIFIC MANNER

2004 ◽  
Vol 08 (01) ◽  
pp. 1-12 ◽  
Author(s):  
Andrea L. Clark ◽  
Linda Mills ◽  
David A Hart ◽  
Walter Herzog
Keyword(s):  
Articular Cartilage ◽  
Mechanical Loading ◽  
Patellofemoral Joint ◽  
Mrna Level ◽  
Recovery Period ◽  
Cartilage Explants ◽  
Mrna Levels ◽  
Biological Responses

Mechanical loading of articular cartilage affects the synthesis and degradation of matrix macromolecules. Much of the work in this area has involved mechanical loading of articular cartilage explants or cells in vitro and assessing biological responses at the mRNA and protein levels. In this study, we developed a new experimental technique to load an intact patellofemoral joint in vivo using muscle stimulation. The articular cartilages were cyclically loaded for one hour in a repeatable and measurable manner. Cartilage was harvested from central and peripheral regions of the femoral groove and patella, either immediately after loading or after a three hour recovery period. Total RNA was isolated from the articular cartilage and biological responses were assessed on the mRNA level using the reverse transcriptase-polymerase chain reaction. Articular cartilage from intact patellofemoral joints demonstrated heterogeneity at the mRNA level for six of the genes assessed independent of the loading protocol. Cyclical loading of cartilage in its native environment led to alterations in mRNA levels for a subset of molecules when assessed immediately after the loading period. However, the increases in TIMP-1 and decreases in bFGF mRNA levels were transient; being present immediately after load application but not after a three hour recovery period.

scholarly journals Single impact injury of Vertebral Endplates, without Structural Disruption Initiates Disc Degeneration In Vitro

2020 ◽  
Author(s):  
Zhengang Sun ◽  
Xiaoshuai Wang ◽  
Yongjie Jiang ◽  
Guoliang Chen ◽  
Zenmin Ling ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Disc Degeneration ◽  
Impact Loading ◽  
Degenerative Changes ◽  
Single Impact ◽  
Spinal Segments ◽  
The Impact ◽  
Impact Injury ◽  
Structural Disruption

Abstract Background : Intervertebral disc degeneration is usually attributed to ageing, genetic, mechanical, and nutritional factors et al. It has been acknowledged that the degenerative process is associated with an aberrant cell-medicated response to structural failures, such as vertebral burst fracture, radial fissures, and endplate fracture. Vertebral endplate trauma, due to, Kirschner wire use or drill holes, can induce degenerative changes of the intervertebral disc (IVD). However, whether a single impact injury of the endplates without structural disruption, which is common seen in the clinic, is sufficiently to initiate disc degeneration is still controversial. This study is to further evolve an in vitro impact injury model of IVD and to investigate if a single impact injury of the endplates without structural disruption can initiate intervertebral disc degeneration(IVDD). Methods. Rats spinal segments (from L1/2 to L5/6, n=54) were harvested and randomly assigned into three groups: Control (n=18), Low Impact (12 J/cm 3 , n=18) and High Impact (25 J/cm 3 , n=18). Samples in both of the impact groups were subjected pure axial impact loading using a custom-made apparatus, and cultured for 14 days. The degenerative process was investigated by using histomorphology and real-time PCR. Results: The discs in both of the impact groups showed significant degenerative changes at 14 days, both of which showed much higher histological scores and up-regulation of the catabolic (MMP-9, MMP-13) genes transcription than that of the control group ( P ＜0.05). The discs with endplate fracture compared to that with intact endplate also showed strongly up-regulated catabolic (MMP-9, MMP-13) genes transcription, and more significant degenerative changes based on the histological scoring ( P ＜0.05). No significant difference of anabolic (TGF-β, Col1α1, Col3α1) genes transcription was found between different groups( P ＞0.05). Conclusion: This study demonstrated that a single impact loading (12 J/cm 3 ) on the spinal segments of the rats could initiate IVDD at 14 days after injury and not only endplate impairment but also a single impact loading without structural disruption could also promote IVDD.

Chondrocyte Death in Articular Cartilage Due to Excessive Mechanical Loading in the Axial and Transverse Directions

2002 ◽  
Author(s):  
Chih-Tung Chen ◽  
Peter A. Torzilli
Keyword(s):  
Articular Cartilage ◽  
Mechanical Loading ◽  
Impact Load ◽  
Impact Loads ◽  
Cyclic Loads ◽  
Matrix Degradation ◽  
Secondary Osteoarthritis ◽  
Load Duration ◽  
Chondrocyte Death ◽  
Traumatic Impact

Chondrocyte injury and death in articular cartilage can cause matrix degradation and is a risk factor for secondary osteoarthritis [1,3–5]. Chondrocyte death can occur due to excessive mechanical loading, such as with a single high traumatic impact load (≥20 MPa), repeated sub-impact loads (≥5 MPa), or extensive cyclic loads (≥1 MPa) [1–5]. Several recent studies have shown that chondrocyte death depends not only on the stress magnitude [2] but also on the stress rate [3], strain rate [5] and load duration [1–2].

Improved Chondrotoxic Profile of Liposomal Bupivacaine Compared With Standard Bupivacaine After Intra-articular Infiltration in a Porcine Model

2017 ◽  
Vol 46 (1) ◽  
pp. 66-71 ◽  
Author(s):  
K. Aaron Shaw ◽  
Colleen Moreland ◽  
Jeremy Jacobs ◽  
Justin M. Hire ◽  
Richard Topolski ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Articular Chondrocytes ◽  
Management Strategies ◽  
Histologic Examination ◽  
Chondrocyte Viability ◽  
Liposomal Bupivacaine ◽  
Stifle Joint ◽  
Chondrocyte Death

Background: Increasingly, liposomal bupivacaine is being used with multimodal pain management strategies. In vitro investigations have shown decreased chondrotoxicity profiles for liposomal bupivacaine; however, there is no evidence regarding its in vivo effects. Hypothesis/Purpose: This study sought to investigate the in vivo chondrotoxicity of liposomal bupivacaine, hypothesizing that there would be increased chondrocyte viability after exposure to liposomal bupivacaine when compared with standard bupivacaine. Study Design: Controlled laboratory study. Methods: Eight juvenile, female Yorkshire cross piglets underwent a lateral stifle joint injection with either 1.3% liposomal bupivacaine or 0.5% bupivacaine. Injections were performed on one joint per animal with no injection to the contralateral knee, which served as the control. Chondrocyte viability was assessed 1 week after injection with a live-dead staining protocol and histologic examination. Results: Significant chondrocyte death was seen with the live-dead staining in the bupivacaine group (33% nonviable cells) in comparison with liposomal bupivacaine (6.2%) and control (5.8%) groups ( P < .01). However, histologic examination showed no differences in chondral surface integrity, fibrillation, and chondrocyte viability. Conclusion: Liposomal bupivacaine was found to be safe for intra-articular injection in this animal model. Although bupivacaine demonstrated decreased chondrocyte viability on a cellular level, histologically there were no changes. This study highlights the dichotomy between fluorescent staining and histologic appearance of articular chondrocytes in short-term analyses of viability. Clinical Relevance: This study supports the peri-articular application of liposomal bupivacaine in the setting of preserved articular cartilage. A single injection of standard bupivacaine did not produce histologic changes in the articular cartilage.

scholarly journals A Three-Dimensional Mechanical Loading Model of Human Osteocytes in Their Native Matrix

2021 ◽  
Author(s):  
Chen Zhang ◽  
Elisabet Farré-Guasch ◽  
Jianfeng Jin ◽  
Huib W. van Essen ◽  
Jenneke Klein-Nulend ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Mechanical Loading ◽  
Bone Matrix ◽  
Three Dimensional ◽  
Matrix Composition ◽  
Mechanical Adaptation ◽  
Custom Made ◽  
Ct Analysis ◽  
Bone Microdamage

AbstractOsteocytes are mechanosensory cells which are embedded in calcified collagenous matrix. The specific native matrix of osteocytes affects their regulatory activity, i.e., transmission of signaling molecules to osteoclasts and/or osteoblasts, in the mechanical adaptation of bone. Unfortunately, no existing in vitro model of cortical bone is currently available to study the mechanosensory function of human osteocytes in their native matrix. Therefore, we aimed to develop an in vitro three-dimensional mechanical loading model of human osteocytes in their native matrix. Human cortical bone explants containing osteocytes in their three-dimensional native matrix were cultured and mechanically loaded by three-point bending using a custom-made loading apparatus generating sinusoidal displacement. Osteocyte viability and sclerostin expression were measured 1–2 days before 5 min loading and 1 day after loading. Bone microdamage was visualized and quantified by micro-CT analysis and histology using BaSO4 staining. A linear relationship was found between loading magnitude (2302–13,811 µɛ) and force (1.6–4.9 N) exerted on the bone explants. At 24 h post-loading, osteocyte viability was not affected by 1600 µɛ loading. Sclerostin expression and bone microdamage were unaffected by loading up to 8000 µɛ. In conclusion, we developed an in vitro 3D mechanical loading model to study mechanoresponsiveness of viable osteocytes residing in their native matrix. This model is suitable to study the effect of changed bone matrix composition in metabolic bone disease on osteocyte mechanoresponsiveness.

The effects of radiofrequency energy probe speed and application force on chondrocyte viability

2007 ◽  
Vol 20 (01) ◽  
pp. 34-37 ◽  
Author(s):  
M. L. Meyer ◽  
J. J Bogdanske ◽  
M. D. Markel ◽  
Y. Lu
Keyword(s):  
Articular Cartilage ◽  
In Vitro Study ◽  
Confocal Laser ◽  
Radiofrequency Energy ◽  
Chondrocyte Viability ◽  
Bovine Articular Cartilage ◽  
Cell Staining ◽  
Chondrocyte Death ◽  
Improper Use

Summary Objective: To determine the thermal effects of monopolar radiofrequency energy (mRFE) on bovine articular cartilage when it was moved at different speeds and using varying application forces. Methods: Thirty-six fresh osteochondral sections divided into two groups (18 sections/group) were used in this study. The first group was tested at three speed rates of mRFE probe (1 mm/sec, 5 mm/sec and 10 mm/sec) at a constant force (50 g) applied to the probe tip. In the second group, three application forces of the probe tip were tested (25 g, 50 g and 75 g) at a constant speed (5 mm/sec) (n=6/test). All tests were performed using a custom-built jig to control the mRFE (Vulcan EAS™) probe during a 20-mm pass on each section. After treatment, viability of osteochondral sections was determined by confocal laser microscopy (CLM) combined with vital cell staining. Results: There were not any significant differences in cartilage thickness of tested osteochondral sections among the different speeds or forces. During the mRFE probe treatments at different speeds, CLM demonstrated that probe application at the speed of 1 mm/ sec caused significantly greater chondrocyte death than at the speeds of 5 and 10 mm/sec, whereas there were no significant differences in chondrocyte death among the variable application forces (p>0.05). Discussion: This in vitro study demonstrated that RFE thermal penetration correlated most closely with probe application speed than application force for this mRFE probe. Clinical relevance: Improper use of mRFE may cause thermal injury on articular cartilage.

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