Abstract
Background:
Knee osteoarthritis (kOA) is a common chronic disease that induces changes in redox status and inflammatory biomarkers, cell death, and motor impairment. Aerobic training can be a non-pharmacological alternative to prevent the progression of the disease.
Objective:
To evaluate the effects of an 8 weeks moderate-intensity treadmill aerobic training program on redox status and inflammatory biomarkers and motor performance in kOA-like changes induced by monosodium iodoacetate (MIA) in rats.
Methods:
Twenty-seven rats were randomly divided into three groups: SHAM; induced kOA (OA); and induced kOA + aerobic training (OAE). Motor performance was evaluated by the number of falls on rotarod test, the total time of displacement and the number of failures on a 100 cm footbridge. Data for cytokines and histology were investigated locally, whereas plasma was used for redox status biomarkers.
Results:
The OA group, compared to the SHAM group, increased 1.13 times the total time of displacement, 6.05 times the number of failures, 2.40 times the number of falls. There was also an increase in cytokine and in thiobarbituric acid reactive substances (TBARS) (IL1β: 5.55-fold, TNF: 2.84-fold, IL10: 1.27-fold, IL6: 1.50-fold, TBARS: 1.14-fold), and a reduction of 6.83% in the total antioxidant capacity (FRAP), and of 35% in the number of chondrocytes. The aerobic training improved the motor performance in all joint function tests matching to SHAM scores. Also, it reduced inflammatory biomarkers and TBARS level at values close to those of the SHAM group, with no change in FRAP level. The number of falls was explained by IL1β and TNF (58%), and the number of failures and the total time of displacement were also explained by TNF (29 and 21%, respectively).
Conclusion:
All findings indicate the efficacy of moderate-intensity aerobic training to regulate inflammatory biomarkers associated with improved motor performance in induced kOA-like changes, thus preventing the loss of chondrocytes.
Introduction
Chondrocytes are responsible for tissue maintenance which impact on joint function and performance (Sophia Fox et al., 2009; ; ). Current literature has reported exercise-induced chondroprotection in knee osteoarthritis (kOA) (; ; ). A potential explanation is the mechanical signal transduction (; Urban, 1994), preserving the cartilage proteoglycans, and promoting chondrocytes modulation (; ). Low-magnitude mechanical stress seems to suppress the pathway of interleukin-1 beta (IL1β) and tumor necrosis factor (TNF) release (Roman-Blas et al., 2009; ; ; ). The IL1β and TNF are inflammatory mediators involved in joint degeneration caused by kOA (; ). The modulation of these cytokines in the joint would regulate the synthesis of proteoglycans and collagen, thereby attenuating the swelling process (; ).
The literature points out redox imbalance and the related increase on reactive oxygen species (ROS), swelling process and necrosis of chondrocytes as the pathophysiology of kOA (; Rose et al., 2012; ). Moreover, redox imbalance and the increased inflammatory biomarkers may cause cartilage damage, neuroinflammatory disease progression, and joint disability (; Watari et al., 2011; , ; ).
Several interventions are used to improve motor performance in patients with kOA (; ), and a low-cost aerobic training may be an alternative (; Semanik et al., 2012). Aerobic training improves blood soluble TNF receptors level and brain-derived neurotrophic factor (BDNF) plasma level in people with kOA (; Simão et al., 2014). Moreover, BDNF seems to impact on chondrocyte differentiation, changing it from proliferative to differentiation program ().
Beyond insufficient information about the modulatory effect of the aerobic training in the knee joint degeneration parameters and possible relationships between joint parameters and motor performance, the literature still presents gaps regarding the effect of aerobic training in the joint preservation on kOA-like changes. Many studies detail mechanotransduction mechanisms but still remain questions about joint function. Moreover, few studies address joint function tests to establish a new therapeutic approach in clinical practice. The current study aimed to investigate the effects of moderate-intensity aerobic training in the inflammatory and redox biomarkers modulation of kOA-like changes, and its possible link to motor performance in rats. Therefore, because experimental kOA induces joint swelling process, we hypothesized that moderate-intensity aerobic training would attenuate the swelling process, favoring the redox balance and preserving chondrocytes in rats with kOA -like changes. Improved modulation in joint biomarkers levels might explain an effect on motor performance.
Materials and Methods
Male Wistar rats were used in the current study that was part of a Masters in Physiology at the Universidade Federal dos Vales do Jequitinhonha e Mucuri (). The project was approved by the local Ethics Committee (protocol 005/2015).
Twenty-seven rats were randomized into three groups: sham group (SHAM), n = 9; induced kOA group (OA), n = 9; and induced kOA + aerobic training (OAE), n = 9. The rats had available water and food (i.e., Nuvilab CR1, Nuvital Nutrientes S/A, Brazil) as they desire, and their environment was controlled (i.e., humidity of 60% and temperature of 22°C).
Induced Osteoarthritis
Twelve-week-old male Wistar rats were anesthetized with ketamine (80 mg/kg, i.p.) and xylazine (15 mg/kg, i.p.). Then, kOA was induced on the right knee joint at 90° flexion by direct infiltration of monosodium iodoacetate (MIA) (1.2 mg diluted in 50 μL saline solution). We used a 29G X 1/2 BD Ultra-FineTM insulin needle (; ; Takahashi et al., 2018). The SHAM group received an infiltration containing 50 μL of saline solution (0.9% NaCl).
Aerobic Training
To perform the aerobic training, a motorized treadmill (Insight®, SP, Ribeirão Preto, Brazil) with six individual lanes and with no inclination was used in the study. OAE group started the familiarization to the treadmill (10 min/day for 5 days) 24 h after the kOA-induction procedure. Then, 24 h after the familiarization period, initiated the training program, which consisted of treadmill running at the velocity of 16 m/min, 3 days per week during 8 weeks (), and the duration of running sessions was increased from 30 to 50 min at the fourth week. The workload of all groups was analyzed at the end of the training program during a treadmill incremental test (initial speed of 10 m min–1, 1% slope, with no electrical stimulus, an increase of 2 m min–1 every 3 min) (; ). The workload (W; J) was calculated as: W = body weight (kg) × total time to fatigue (min) × treadmill speed (m min–1) × sin θ (treadmill inclination) × 10 ().
Evaluation of Motor Performance – Forced Locomotion (Rotarod Test)
In the rotarod test (Scienlabor, Brazil), the rats are stimulated to walk around a circle drum surface. The rotarod test measures balance, coordination, physical performance, and motor-planning by calculating the number of falls during determined speed. The time that a given rat stays on this circle rod represents the joint function. We used a protocol adapted from to quantify the number of falls of rats during 3-min period keeping a fixed speed of 8 revolutions per minute (rpm) ().
Locomotion Test on a Footbridge
Rats locomoted on a footbridge to investigate joint function when moving a short distance. The footbridge had a length of 100 cm delimited by 3 mm thick aluminum filets. Image and time to complete a single pass during animals’ locomotion were recorded. Records were later analyzed by a blinded investigator to quantify the total time of displacement and the number of times each rat stepped out of the space between the filets (number of failures).
Euthanasia
Animals were euthanized individually by decapitation and their right knee joints were analyzed. Approximately 12 mL of blood was collected in tubes containing ethylenediaminetetraacetic acid (EDTA), then centrifuged at 500 × g for 10 min and the serum aliquoted and frozen in a −80°C freezer for further analysis.
Joint Lavage
For later analysis, the joint lavage (JAL) supernatants were stored at −80°C. Immediately after recovering JAL, we removed the joint capsule and stored it in a freezer at −80°C. Moreover, we homogenized the sample in phosphate buffer and also frozen it at −80°C for future analysis. IL1β, TNF, and interleukin-10 (IL10) knee joint biomarkers were analyzed according to the manufacturer’s instructions by ELISA kits (DuoSet, R&D Systems, United States).
Macerated Joint Capsule
The capsule was placed into a beaker with 750 μL of cytokine extraction solution, and a tissue homogenizer (Tecnal, TE-103) was used to obtain the macerate. Then, the capsule macerate was processed at 8 rpm speed for 2 min, the volume centrifuged at 3500 xg at 4°C for 10 min and stored in a freezer. BDNF and interleukin-6 (IL6) levels were analyzed according to the manufacturer’s instructions by ELISA.
Measurements of Redox Status
The reaction of the thiobarbituric acid with malondialdehyde (MDA) was used to determine lipid peroxidation by thiobarbituric acid reactive substances (TBARS) plasma levels (). The ferric reducing ability of plasma (FRAP), i.e., the reduction of ferric-tripyridyltriazine [Fe(III)-TPTZ] complex to ferrous-tripyridyltriazine [Fe(II)-TPTZ] () was used to determine the total antioxidant capacity. The Bradford method using bovine serum albumin was used as a standard to determine the samples protein levels ().
Histology
The right knee joints were placed in 4% neutral-buffered formalin for 24 h. After that, tissues were placed in 10% EDTA at pH 7.4 for decalcification (). Sagittal sections were prepared from knee joints. Two slides of the femur compromised by MIA induction or SHAM were prepared for histological analyses. Three cuts in each slide. Tissues were placed in formalin, dehydrated in a graded series of ethanol and xylol, embedded in paraffin, cut into 6 μm serial sections, and stained with hematoxylin-eosin.
Quantification of Chondrocytes
To investigate the number of active cells, the middle third of the joint was used. For cell counting, the nuclei stained by hematoxylin present in the superficial, intermediate and transitional areas were considered. The analysis was performed on the articular facet of the right femur. The image was captured by a microscope with a 40 × magnification. The software Image J was used for cell counting. Two micrographs were taken in series and a blinded investigator analyzed them on different days (ICC = 0.99). For statistical analysis, the average number of cells was established and used.
Statistical Analysis
We used the SPSS statistical package, version 22.0 (Inc., United States) and Graph Pad Prism, version 5.0 (Inc., United States). Data are expressed as mean ± standard error (S.E.M). Normality of data was assessed using the Shapiro–Wilk test. For comparisons, we used the one-way ANOVA with Tukey’s post hoc tests for parametric data (Body mass, IL6 and number of chondrocytes) and Kruskal-Wallis with Dunn’s post hoc test for non-parametric data (IL1β, TNF, IL10, TBARS, FRAP, number of falls, total time of displacement, and number of failures). Effect Size (d) was checked in G∗Power 3.1.9.2 program. Effect size conventions for test family (F tests) and one-way ANOVA: d = 0.10 (small); d = 0.25 (medium); d = 0.40 (large). The Spearman correlation investigated associations between two intra-articular biomarkers of joint damage (IL1β, TNF) and joint function tests: number of falls, total time of displacement and number of failures.
To determine intra-examiner reliability for the evaluated outcomes, the intraclass correlation coefficient (ICC) adopting a 95% confidence interval was determined. Multiple linear stepwise regression models confirmed the association between selected biomarkers and joint function, adjusting by Bonferroni at α = 0.017. Graphs were built using the GraphPad Prism 5 (GraphPad Software Inc., San Diego, CA, United States).
Results
Twenty-seven animals were available for this study, recovered uneventfully from surgery and exercise procedure. By the end of the study, the rats were about 6 months old. No significant differences were observed in body weight between the three groups at the surgery and at the 8th-week post-surgery (Figure 1).
FIGURE 1
Aerobic training increased the total workload of OAE rats by 64% as compared to sham and OA groups (SHAM: 23.8 ± 8.0 J, OA: 23.7 ± 11.0 J, OAE: 69.2 ± 15.9 J, p = 0.0002, d = 0.85). Levels of IL1β, TNF, IL10 in the joint washed and the level of IL6 in the joint capsule increased respectively by 5.55, 2.84, 1.27, and 1.50-fold in the OA group. In OAE group compared with OA group, the aerobic training modulated levels of these joint cytokines close to those in the SHAM group (IL1β: p < 0.0001, d = 1.18; TNF: p = 0.0001, d = 1.00; IL10: p < 0.0001, d = 1.32; IL6: p = 0.0001, d = 1.68) (Figure 2).
FIGURE 2
The BDNF level in the OAE group was 41% higher than in the OA group (p = 0.05; d = 0.86). The induction of kOA-like changes increased by 1.14 times the TBARS plasma level and reduced the FRAP plasma level by 6.83% (p = 0.02) in the OA group compared with SHAM group. In OAE group compared with OA group, the aerobic training returned the plasma level of TBARS close to those in the SHAM group, without changing the total antioxidant capacity (TBARS: p = 0.001; d = 0.86; P = 0.95; FRAP: p = 0.05; d = 0.62) (Figure 3).
FIGURE 3
The analysis of the joint function tests showed that the kOA-induction (OA group) increased by 1.13 times the total time of displacement on a 100 cm footbridge and increased by 6.05 times the number of failures in the course when compared with SHAM group. The number of falls during the rotarod test increased 2.40 times in the OA group compared with SHAM. Therefore, in OAE group compared with OA group, the aerobic training had a positive effect on the disease, since it improved the performance in the three parameters evaluated, matching the SHAM score (Number of falls: p = 0.002; d = 1.05; Number of failures: p = 0.0002 d = 0.26; Total time of displacement: p = 0.005; d = 0.72) (Figure 4).
FIGURE 4
Number of falls (rs = 0.69; p = 0.0003) and number of failures (rs = 0.66; p = 0.0002) were associated with the IL1β. Functional performance measures: number of falls in the rotarod test (rs = 0.73; p < 0.0001); total time of displacement (rs = 0.63; p = 0.0005); and number of failures (rs = 0.52; p = 0.005) were associated with the TNF. Multiple linear stepwise regression models of IL1β and TNF explained 58% of the variability in the number of falls (IL1 β: p = 0.001; TNF: p = 0.002). TNF only explained 29% of the variability of the total time of displacement (p = 0.02) and 21% of the variability of the number of failures (p = 0.02). The increase of 1 pg/mL in intra-articular IL1β level leads to an increase of 0.40 points in the number of falls. The increase of 1 pg/mL in the intra-articular TNF level leads to an increase of 0.51 points in the number of falls; 0.57 s in the total time of displacement; and 0.49 points in the number of failures (Table 1).
TABLE 1
| Joint damage biomarkers | Number of falls | Total time of displacement | Number of failures | ||||||
| B | p | R2 | β | P | R2 | B | p | R2 | |
| 0.58 | 0.29 | 0.21 | |||||||
| IL1β (pg/mL) | 0.40 | 0.001∗ | −0.003 | 0.99 | 0.32 | 0.10 | |||
| TNF (pg/mL) | 0.51 | 0.002∗ | 0.57 | 0.02∗ | 0.49 | 0.02∗ | |||
Multiple linear stepwise regression analysis.
β, Standardized regression coefficient; R2, Adjusted R square. IL1β, Interleukin-1 beta; TNF, Tumor necrosis factor.
Quantification of hematoxylin-stained nuclei showed that the induction of kOA reduced the number of cells (chondrocytes) alive by approximately 35% compared with the SHAM group. Aerobic training (OAE group) prevented chondrocyte cell death since the number of active cells in the trained group was 51.35% higher than in the OA group (p < 0.0001) (Figure 5).
FIGURE 5
Discussion
Overall, the current study showed an association between worse joint function and high levels of joint degeneration biomarkers, as indicated by high levels of TNF and IL1β. Moreover, aerobic training could reverse local inflammatory biomarkers and decrease systemic MDA level with an improvement in gait tasks, motor, and physical performance. Histological data of the femoral joint also confirmed the beneficial effect of the proposed exercise to the kOA-induced.
Scientific evidence suggests the involvement of inflammatory biomarkers and redox status parameters for the advancement and progression of kOA (; ). In patients with kOA, chondrocytes and synovial cells stimulate the production of inflammatory cytokines, i.e., IL1β and TNF (; ; Wojdasiewicz et al., 2014; ). evidenced that IL1β and TNF are responsible for mitochondrial DNA damage in kOA, promoting the development of ROS and chondrocyte death ().
The compression forces of low magnitude during physical exercise seem to promote physiological control. Such control modulates the synthesis of collagen and proteoglycans possibly inhibited in swelling joints (; ; ). This could indicate the greater maintenance of proteoglycan in the joint cartilage of rats exposed to moderate exercise (; ; ; ). Thus, the authors suggest that the positive effects are linked to the decrease of chondrocyte necrosis in the experimental group, lowering metabolites of cell death and induction of inflammatory factors expression (). The high level of ROS would act on the expression of cytokines, making worse the swelling. The ROS may initiate the cartilage degeneration and advancement of lipid peroxidation in chondrocytes (Yudoh et al., 2005; ; ; Watari et al., 2011).
In kOA, inflammatory cytokines alter the joint biochemical balance inducing chondrocyte necrosis. The production and secretion of catabolic cytokines augment ROS production inducing a redox imbalance. Free radicals interacting with chondrocyte DNA acts directly by altering cellular components, i.e., proteoglycans, collagens, and protein oxidation, favoring cartilage degeneration, which may compromise the thickness of the synovial fluid, and the synthesis of other components (; Rose et al., 2012; ). Physical and functional damages occur due to tissue structural change. Catabolic cytokines (IL1β and TNF), and regulatory cytokine (IL6) are probably the main factors in this process, facilitating paths of degeneration by activating paths such as matrix metalloproteases (Rojas-Ortega et al., 2015; ). The augmented inflammatory profile marks the loss of extracellular matrix integrity, developing an oxidative injury, and, lastly, the chondrocytes death. The death of these chondrocytes seems related to the compromised joint function since this cellular type is responsible for the mobilization of essential components that assure the main functions of load distribution and reduction of friction during static or dynamic exercises that guarantee the joint function. assessed histological data of depth ratio of lesions demonstrating that 4 weeks of moderate exercise almost treated kOA symptoms in rats (). Moreover, the level of MDA increased in induced kOA dogs. This intensification revealed degeneration of the type II collagen (), implying a relationship between redox imbalance and cartilage degeneration. Oxidative injury can result in cell death, triggering particles and oxidized molecules release, cellular degeneration, and increased inflammation.
kOA subjects have greater ROS plasma level and lower antioxidant supplies (; ). The redox imbalance can play a critical role in the cartilage degeneration (; ). Thus, in both human and animal, kOA transporters have a high level of systemic biomarkers which means cellular damage led by ROS. As a consequence, cell-matrix may be compromised. Inhibition of this course can successfully avoid degeneration of articular cartilage and neo-formation of type II collagen ().
The transduction of mechanical signals of dynamic pressure in chondrocytes may favor the pathways that counteract tissue catabolism. assessed anabolic responses on bovine cartilage in vitro cells culture inducing matrix biosynthesis with different compression ranges (10, 20, and 30%) and demonstrated that moderate dynamic compression can exert an “anti-catabolic” effect, and suppress the expression of TNF, IL6, and soluble IL6 receptors (). The catabolism control appears to relate to a range of compression frequency, amplitude, and to the low-to-moderate intensity load, showing the importance of a voltage amplitude threshold for the regulation of inflammatory paths and cell survival (; ; Rojas-Ortega et al., 2015; ). Moreover, the exercise load influences BDNF production and release (; Yarrow et al., 2010; Szuhany et al., 2015). BDNF is an important growth factor expressed in joint chondrocytes and in epiphyseal plaques of kOA subjects. BDNF causes the growth and, mainly, differentiation () of chondrocytes, inducing the proliferation pathway that can act as a restoration mediator. Furthermore, BDNF level has been also systemically increased in patients with kOA (Simão et al., 2014).
Because mild- to moderate-intensity exercises seem to play an anti-inflammatory role, we decided to perform a moderate-intensity aerobic training on a treadmill to promote mechanical biostimulation caused by joint compression (; ; ; ; ). In the current study, we decided to use an aerobic training similar to the study of that investigated the effects of impact exercise on the kOA-induced cartilage aspects in rats. This protocol was chosen because the data of that investigation demonstrated that aerobic training contributed to the preservation of some joint cartilage parameters in experimental kOA. Moreover, the overload to the intensity and inclination of exercise sessions were not applied, once it could directly affect the dynamic compression of knee joint cartilage cells, leading to misinterpretations of our results. Thus, active mechanotransduction induces changes in oxygen tension and subsequent positive effects on matrix synthesis and cell growth (Urban, 1994; ). These effects are explained by the displacement of growth factors or cellular cytokines by shifting cellular metabolism (Tilwani et al., 2017). Finally, our results showed that the proposed training offered an inflammatory control, confirmed by the modulation effect in biomarkers levels (IL1β and TNF in the joint wash; IL10 and IL6 in the knee joint).
The positive effects of aerobic training are attributed to the ability of the suppression of signals transduction paths of inflammatory and catabolic mediators together with the stimulation of anabolic paths. In vitro studies have verified that mild to moderate mechanical stress inhibits swelling by suppression of IL1β, TNF and the transcription of various joint degeneration inflammatory biomarkers (; Rose et al., 2012; Yamabe et al., 2013). Experimental kOA studies showed a positive effect of aerobic training, whereas high-intensity training had a deleterious effect (; ; Rojas-Ortega et al., 2015; ). These data seem to determine the role of aerobic exercise appropriate dose (intensity, frequency, and duration) in modulating chondrocyte response (; ; ). In rats without previous kOA induction, high-intensity exercises in many treadmill angles were not able to induce knee damage (; ). Thus, biochemical responses appear to be sensitive to the force only in the injury. Our data once again is in accordance to this premise since the proposed protocol was effective in dropping the joint IL1β and TNF in the trained group, as well as in reducing the TBARS systemic level, augmenting knee joint function and physical performance. In the present study, we identified an increased chondrocytes number in the OAE group. It is already known that chondrocytes are responsible for tissue maintenance which impact on joint function and motor performance (Sophia Fox et al., 2009; ). Thus, we speculate that the largest number of chondrocytes and the lower joint degradation cytokines level (IL1β and TNF) (; , ; Rojas-Ortega et al., 2015) might have preserved the proteoglycans and collagen joint which lead to better motor performance of the OAE group compared to the OA group. Based on the results, exercise prevented the increase of inflammatory biomarkers, and, consequently, prevented the loss of chondrocytes (the only marker evaluated). We cannot extrapolate our results to the whole joint, because the number of chondrocytes was the only analysis. This theory needs to be better clarified ahead. Our study is innovative as it points out the benefits of a therapeutic approach to an experimental OA model. Assessing the effect on physical performance of the animals it was demonstrated that the dose-controlled impact is achieved by ways not fully elucidated in this study. The modulation of inflammation, due to the known effects of aerobic training, has affected the redox status balance, lowering oxidative damage, improving motor performance in functional tasks.
A limitation of this study was that we did not determine kOA-like changes according to the OARSI score. However, it was not possible because we used a single hematoxylin and eosin (H&E) staining for analysis. Thus, immunohistochemistry assessments on cartilage tissue would be useful in future studies.
Conclusion
To conclude, a moderate-intensity aerobic treadmill training appears to modulate chondrocytes via activation of anabolic paths, swelling control by IL1β and TNF levels modulation, systemic TBARS level lowering and positive regulation in joint BDNF level, resulting in physical and motor performance improvements. As a perspective, the efficacy of the training protocol used here should be investigated in older animals.
Statements
Data availability statement
The datasets generated for this study are available on request to the corresponding author.
Ethics statement
This animal study was reviewed and approved by the Commission on Ethics in Animal Use of the Universidade Federal dos Vales do Jequitinhonha e Mucuri (protocol 005/2015). Written informed consent was obtained from the owners for the participation of their animals in this study.
Author contributions
JM, VM, MO, HL, AC, CC, and AL conceived and designed the study. JM, VM, GA, SF, JS, RT-G, DS, MO, HL, AC, AF, CC, JP, and AL contributed to analysis and interpretation of the data. JM, VM, SF, SS, JS, RT-G, DS, TD, and AL drafted the article. JM, VM, SF, MO, HL, AC, AF, CC, JP, MB-F, and AL critically revised the article for important intellectual content. JM, VM, GA, SF, JS, RT-G, DS, MO, HL, AC, AF, CC, JP, VO, MB-F, and AL approved the final article. JM, SF, MO, HL, AC, JP, and AL statistically expertised the study. VM, MO, HL, AC, AF, CC, and AL provisioned the study materials. VM, GA, RT-G, DS, MO, AF, CC, and AL contributed to administrative, technical, or logistic support.
Funding
This study was supported in part by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (Numbers 408721/2016-2 and 303746/2018-1), the Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) (Numbers APQ-02503-16, APQ-01239-14, and APQ-03119-18), and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) (finance code 001).
Acknowledgments
We acknowledge who provided data from her master’s degree conducted in the Universidade Federal dos Vales do Jequitinhonha e Mucuri. Besides, the assistance of the Brazilian Society of Physiology is gratefully acknowledged.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
References
1
AbruzzoP.EspositoF.MarchionniC.Di TullioS.BeliaS.FulleS.et al (2013). Moderate exercise training induces ROS-related adaptations to skeletal muscles.Int. J. Sports Med.34676–687. 10.1055/s-0032-1323782
2
AkkirajuH.NoheA. (2015). Role of chondrocytes in cartilage formation, progression of osteoarthritis and cartilage regeneration.J. Dev. Biol.3177–192. 10.3390/jdb3040177
3
AltindagO.ErelO.AksoyN.SelekS.CelikH.KaraoglanogluM. (2007). Increased oxidative stress and its relation with collagen metabolism in knee osteoarthritis.Rheumatol. Int.27339–344. 10.1007/s00296-006-0247-8
4
AssisL.MilaresL.AlmeidaT.TimC.MagriA.FernandesK.et al (2016). Aerobic exercise training and low-level laser therapy modulate inflammatory response and degenerative process in an experimental model of knee osteoarthritis in rats.Osteoarthr. Cartil.24169–177. 10.1016/j.joca.2015.07.020
5
AtturM.KrasnokutskyS.StatnikovA.SamuelsJ.LiZ.FrieseO.et al (2015). Low-grade inflammation in symptomatic knee osteoarthritis: prognostic value of inflammatory plasma lipids and peripheral blood leukocyte biomarkers.Arthritis Rheumatol.672905–2915. 10.1002/art.39279
6
AtturM.Krasnokutsky-SamuelsS.SamuelsJ.AbramsonS. B. (2013). Prognostic biomarkers in osteoarthritis.Curr. Opin. Rheumatol.25:136. 10.1097/BOR.0b013e32835a9381
7
BalthazarC. H.LeiteL. H.RodriguesA. G.CoimbraC. C. (2009). Performance-enhancing and thermoregulatory effects of intracerebroventricular dopamine in running rats.Pharmacol. Biochem. Behav.93465–469. 10.1016/j.pbb.2009.06.009
8
BeckettJ.JinW.SchultzM.ChenA.TolbertD.MoedB. R.et al (2012). Excessive running induces cartilage degeneration in knee joints and alters gait of rats.J. Orthop. Res.301604–1610. 10.1002/jor.22124
9
BenzieI. F.StrainJ. J. (1996). The ferric reducing ability of plasma (FRAP) as a measure of “antioxidant power”: the FRAP assay.Anal. Biochem.23970–76. 10.1006/abio.1996.0292
10
BlasioliD. J.KaplanD. L. (2013). The roles of catabolic factors in the development of osteoarthritis.Tissue Eng. Part B Rev.20355–363. 10.1089/ten.teb.2013.0377
11
BradfordM. M. (1976). A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding.Anal. Biochem.72248–254. 10.1016/0003-2697(76)90527-3
12
CharlierE.RelicB.DeroyerC.MalaiseO.NeuvilleS.ColléeJ.et al (2016). Insights on molecular mechanisms of chondrocytes death in osteoarthritis.Int. J. Mol. Sci.17:2146. 10.3390/ijms17122146
13
CifuentesD.RochaL.SilvaL.BritoA.Rueff-BarrosoC.PortoL.et al (2010). Decrease in oxidative stress and histological changes induced by physical exercise calibrated in rats with osteoarthritis induced by monosodium iodoacetate.Osteoarthr. Cartil.181088–1095. 10.1016/j.joca.2010.04.004
14
FehrenbacherA.SteckE.RickertM.RothW.RichterW. (2003). Rapid regulation of collagen but not metalloproteinase 1, 3, 13, 14 and tissue inhibitor of metalloproteinase 1, 2, 3 expression in response to mechanical loading of cartilage explants in vitro.Arch. Biochem. Biophys.41039–47. 10.1016/s0003-9861(02)00658-6
15
GaloisL.EtienneS.GrossinL.CournilC.PinzanoA.NetterP.et al (2003). Moderate-impact exercise is associated with decreased severity of experimental osteoarthritis in rats.Rheumatology42692–693. 10.1093/rheumatology/keg094
16
GeneenL. J.MooreR. A.ClarkeC.MartinD.ColvinL. A.SmithB. H. (2017). Physical activity and exercise for chronic pain in adults: an overview of cochrane reviews.Cochrane Database Syst. Rev.1:CD011279.
17
GermanouE. I.ChatzinikolaouA.MalliouP.BenekaA.JamurtasA. Z.BikosC.et al (2013). Oxidative stress and inflammatory responses following an acute bout of isokinetic exercise in obese women with knee osteoarthritis.Knee20581–590. 10.1016/j.knee.2012.10.020
18
GolightlyY. M.AllenK. D.CaineD. J. (2012). A comprehensive review of the effectiveness of different exercise programs for patients with osteoarthritis.Phys. Sports Med.4052–65. 10.3810/psm.2012.11.1988
19
GomesW. F.LacerdaA. C. R.MendonçaV. A.ArrieiroA. N.FonsecaS. F.AmorimM. R.et al (2012). Effect of aerobic training on plasma cytokines and soluble receptors in elderly women with knee osteoarthritis, in response to acute exercise.Clin. Rheumatol.31759–766. 10.1007/s10067-011-1927-7
20
GoranovN. V. (2007). Serum markers of lipid peroxidation, antioxidant enzymatic defense, and collagen degradation in an experimental (Pond-Nuki) canine model of osteoarthritis.Vet. Clin. Pathol.36192–195. 10.1111/j.1939-165x.2007.tb00208.x
21
GuzmanR. E.EvansM. G.BoveS.MorenkoB.KilgoreK. (2003). Mono-iodoacetate-induced histologic changes in subchondral bone and articular cartilage of rat femorotibial joints: an animal model of osteoarthritis.Toxicol. Pathol.31619–624. 10.1080/714044694
22
HenrotinY.BrucknerP.PujolJ.-P. (2003). The role of reactive oxygen species in homeostasis and degradation of cartilage.Osteoarthr. Cartil.11747–755. 10.1016/s1063-4584(03)00150-x
23
HillR. J.MasonH. M.YeipG.MerchantS. S.OlsenA. L.StottR. D.et al (2017). The influence of oblique angle forced exercise in surgically destabilized stifle joints is synergistic with bone, but antagonistic with cartilage in an ovine model of osteoarthritis.Arthritis2017:7481619. 10.1155/2017/7481619
24
HuiW.YoungD. A.RowanA. D.XuX.CawstonT. E.ProctorC. J. (2016). Oxidative changes and signalling pathways are pivotal in initiating age-related changes in articular cartilage.Ann. Rheum. Dis.75449–458. 10.1136/annrheumdis-2014-206295
25
HunterD. J.EcksteinF. (2009). Exercise and osteoarthritis.J. Anat.214197–207.
26
HutchisonM. R. (2012). BDNF alters ERK/p38 MAPK activity ratios to promote differentiation in growth plate chondrocytes.Mol. Endocrinol.261406–1416. 10.1210/me.2012-1063
27
IijimaH.AoyamaT.ItoA.YamaguchiS.NagaiM.TajinoJ.et al (2015). Effects of short-term gentle treadmill walking on subchondral bone in a rat model of instability-induced osteoarthritis.Osteoarthr. Cartil.231563–1574. 10.1016/j.joca.2015.04.015
28
JimsonS.BalachanderN.MasthanK.ElumalaiR. (2014). A comparative study in bone decalcification using different decalcifying agents.Int. J. Sci. Res.31226–1229.
29
KimJ.XuM.XoR.MatesA.WilsonG.PearsallA.et al (2010). Mitochondrial DNA damage is involved in apoptosis caused by pro-inflammatory cytokines in human OA chondrocytes.Osteoarthr. Cartil.18424–432. 10.1016/j.joca.2009.09.008
30
KnoblochT. J.MadhavanS.NamJ.AgarwalS.Jr.AgarwalS. (2008). Regulation of chondrocytic gene expression by biomechanical signals.Crit. Rev. Eukaryot. Gene Expr.18:139. 10.1615/critreveukargeneexpr.v18.i2.30
31
KoikeM.NojiriH.OzawaY.WatanabeK.MuramatsuY.KanekoH.et al (2015). Mechanical overloading causes mitochondrial superoxide and SOD2 imbalance in chondrocytes resulting in cartilage degeneration.Sci. Rep.5:11722. 10.1038/srep11722
32
KunischE.KinneR. W.AlsalamehR. J.AlsalamehS. (2016). Pro-inflammatory IL-1beta and/or TNF-alpha up-regulate matrix metalloproteases-1 and-3 m RNA in chondrocyte subpopulations potentially pathogenic in osteoarthritis: in situ hybridization studies on a single cell level.Int. J. Rheum. Dis.19557–566. 10.1111/1756-185X.12431
33
LacerdaA. C. R.MarubayashiU.BalthazarC. H.LeiteL. H.CoimbraC. C. (2006). Central nitric oxide inhibition modifies metabolic adjustments induced by exercise in rats.Neurosci. Lett.410152–156. 10.1016/j.neulet.2006.09.067
34
LeongD. J.GuX. I.LiY.LeeJ. Y.LaudierD. M.MajeskaR. J.et al (2010). Matrix metalloproteinase-3 in articular cartilage is upregulated by joint immobilization and suppressed by passive joint motion.Matrix Biol.29420–426. 10.1016/j.matbio.2010.02.004
35
LiY.FrankE. H.WangY.ChubinskayaS.HuangH.-H.GrodzinskyA. J. (2013). Moderate dynamic compression inhibits pro-catabolic response of cartilage to mechanical injury, TNF-α and IL-6, but accentuates degradation above a strain threshold.Osteoarthr. Cartil.21933–941.
36
LiZ.LiuS.-Y.XuL.XuS.-Y.NiG.-X. (2017). Effects of treadmill running with different intensity on rat subchondral bone.Sci. Rep.7:1977. 10.1038/s41598-017-02126-z
37
LiZ.-C.HanN.LiX.LiG.LiuY.-Z.SunG.-X.et al (2015). Decreased expression of microRNA-130a correlates with TNF-α in the development of osteoarthritis.Int. J. Clin. Exp. Pathol.8:2555.
38
LittleC. B.GhoshP. (1997). Variation in proteoglycan metabolism by articular chondrocytes in different joint regions is determined by post-natal mechanical loading.Osteoarthr. Cartil.549–62. 10.1016/s1063-4584(97)80031-3
39
LoeserR. F. (2010). Age-related changes in the musculoskeletal system and the development of osteoarthritis.Clin. Geriatr. Med.26371–386. 10.1016/j.cger.2010.03.002
40
LoeserR. F.GoldringS. R.ScanzelloC. R.GoldringM. B. (2012). Osteoarthritis: a disease of the joint as an organ.Arthritis Rheum.641697–1707. 10.1002/art.34453
41
MabeyT.HonsawekS. (2015). Cytokines as biochemical markers for knee osteoarthritis.World J. Orthop.6:95. 10.5312/wjo.v6.i1.95
42
MartinsJ. B. (2017). Treinamento Físico Moderado Em Esteira Modula Biomarcadores Articulares E Melhora O Desempenho Funcional Em Ratos Com Osteoartrite De Joelho Induzida. Ph.D. thesis, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, MG.
43
MohammadiM. F.MoghaddamA. H.MirkarimpurH. (2013). The effects of a moderate exercise program on knee osteoarthritis in male wistar rats.Ir. J. Basic Med. Sci.16:683.
44
NaS. S.KimS. G.YongM. S.HwangboG. (2014). Study of treadmill exercise effect on rats with osteoarthritis using proteomic analysis.J. Phys. Ther. Sci.26487–490. 10.1589/jpts.26.487
45
NiG.-X.LeiL.ZhouY.-Z. (2012). Intensity-dependent effect of treadmill running on lubricin metabolism of rat articular cartilage.Arthritis Res. Ther.14:R256. 10.1186/ar4101
46
NiG.-X.LiuS.-Y.LeiL.LiZ.ZhouY.-Z.ZhanL.-Q. (2013). Intensity-dependent effect of treadmill running on knee articular cartilage in a rat model.BioMed. Res. Int.2013:172392. 10.1155/2013/172392
47
NofujiY.SuwaM.MoriyamaY.NakanoH.IchimiyaA.NishichiR.et al (2008). Decreased serum brain-derived neurotrophic factor in trained men.Neurosci. Lett.43729–32. 10.1016/j.neulet.2008.03.057
48
O’HaraB.UrbanJ.MaroudasA. (1990). Influence of cyclic loading on the nutrition of articular cartilage.Ann. Rheum. Dis.49536–539. 10.1136/ard.49.7.536
49
OhkawaH.OhishiN.YagiK. (1979). Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction.Anal. Biochem.95351–358. 10.1016/0003-2697(79)90738-3
50
OstalowskaA.BirknerE.WiechaM.KasperczykS.KasperczykA.KapolkaD.et al (2006). Lipid peroxidation and antioxidant enzymes in synovial fluid of patients with primary and secondary osteoarthritis of the knee joint.Osteoarthr. Cartil.14139–145. 10.1016/j.joca.2005.08.009
51
ParkS.HungC.AteshianG. (2004). Mechanical response of bovine articular cartilage under dynamic unconfined compression loading at physiological stress levels.Osteoarthr. Cartil.1265–73. 10.1016/j.joca.2003.08.005
52
PielM. J.KroinJ. S.van WijnenA. J.KcR.ImH.-J. (2014). Pain assessment in animal models of osteoarthritis.Gene537184–188. 10.1016/j.gene.2013.11.091
53
PooleA.KobayashiM.YasudaT.LavertyS.MwaleF.KojimaT.et al (2002). Type II collagen degradation and its regulation in articular cartilage in osteoarthritis.Ann. Rheum. Dis.61(Suppl. 2), ii78–ii81.
54
Primola-GomesT. N.CamposL. A.Lauton-SantosS.BalthazarC. H.GuatimosimS.CapettiniL. S.et al (2009). Exercise capacity is related to calcium transients in ventricular cardiomyocytes.J. Appl. Physiol.107593–598. 10.1152/japplphysiol.91218.2008
55
QuinnT. M.GrodzinskyA. J.BuschmannM. D.KimY.-J.HunzikerE. B. (1998). Mechanical compression alters proteoglycan deposition and matrix deformation around individual cells in cartilage explants.J. Cell Sci.111573–583.
56
ReedK. N.WilsonG.PearsallA.GrishkoV. I. (2014). The role of mitochondrial reactive oxygen species in cartilage matrix destruction.Mol. Cell. Biochem.397195–201. 10.1007/s11010-014-2187-z
57
ReganE.FlannellyJ.BowlerR.TranK.NicksM.CarboneB. D.et al (2005). Extracellular superoxide dismutase and oxidant damage in osteoarthritis.Arthritis Rheum.523479–3491. 10.1002/art.21387
58
RiosJ. L.BoldtK. R.MatherJ. W.SeerattanR. A.HartD. A.HerzogW. (2018). Quantifying the effects of different treadmill training speeds and durations on the health of rat knee joints.Sports Med. Open4:15. 10.1186/s40798-018-0127-2
59
Rojas-OrtegaM.CruzR.Vega-LópezM. A.Cabrera-GonzálezM.Hernández-HernándezJ. M.Lavalle-MontalvoC.et al (2015). Exercise modulates the expression of IL-1β and IL-10 in the articular cartilage of normal and osteoarthritis-induced rats.Pathol. Res. Pract.211435–443. 10.1016/j.prp.2015.01.008
60
Roman-BlasJ. A.Contreras-BlascoM. A.LargoR.Álvarez-SoriaM. A.CastañedaS.Herrero-BeaumontG. (2009). Differential effects of the antioxidant N-acetylcysteine on the production of catabolic mediators in IL-1β-stimulated human osteoarthritic synoviocytes and chondrocytes.Eur. J. Pharmacol.623125–131. 10.1016/j.ejphar.2009.09.016
61
RoseJ.SöderS.SkhirtladzeC.SchmitzN.GebhardP.SesselmannS.et al (2012). DNA damage, discoordinated gene expression and cellular senescence in osteoarthritic chondrocytes.Osteoarthr. Cartil.201020–1028. 10.1016/j.joca.2012.05.009
62
SemanikP. A.ChangR. W.DunlopD. D. (2012). Aerobic activity in prevention and symptom control of osteoarthritis.PM R4S37–S44. 10.1016/j.pmrj.2012.02.015
63
SimãoA. P.MendonçaV. A.de Oliveira AlmeidaT. M.SantosS. A.GomesW. F.CoimbraC. C.et al (2014). Involvement of BDNF in knee osteoarthritis: the relationship with inflammation and clinical parameters.Rheumatol. Int.341153–1157. 10.1007/s00296-013-2943-5
64
Sophia FoxA. J.BediA.RodeoS. A. (2009). The basic science of articular cartilage: structure, composition, and function.Sports Health1461–468. 10.1177/1941738109350438
65
SzuhanyK. L.BugattiM.OttoM. W. (2015). A meta-analytic review of the effects of exercise on brain-derived neurotrophic factor.J. Psychiatr. Res.6056–64. 10.1016/j.jpsychires.2014.10.003
66
TakahashiI.MatsuzakiT.KurokiH.HosoM. (2018). Induction of osteoarthritis by injecting monosodium iodoacetate into the patellofemoral joint of an experimental rat model.PLoS One13:e0196625. 10.1371/journal.pone.0196625
67
TilwaniR.VessillierS.Pingguan-MurphyB.LeeD.BaderD.ChowdhuryT. (2017). Oxygen tension modulates the effects of TNFα in compressed chondrocytes.Inflamm. Res.6649–58. 10.1007/s00011-016-0991-5
68
UrbanJ. (1994). The chondrocyte: a cell under pressure.Rheumatology33901–908. 10.1093/rheumatology/33.10.901
69
WatariT.NaitoK.SakamotoK.KurosawaH.NagaokaI.KanekoK. (2011). Evaluation of the effect of oxidative stress on articular cartilage in spontaneously osteoarthritic STR/OrtCrlj mice by measuring the biomarkers for oxidative stress and type II collagen degradation/synthesis.Exp. Ther. Med.2245–250. 10.3892/etm.2011.196
70
WojdasiewiczP.PoniatowskiŁA.SzukiewiczD. (2014). The role of inflammatory and anti-inflammatory cytokines in the pathogenesis of osteoarthritis.Mediators Inflamm.2014:561459. 10.1155/2014/561459
71
YamabeS.HiroseJ.UeharaY.OkadaT.OkamotoN.OkaK.et al (2013). Intracellular accumulation of advanced glycation end products induces apoptosis via endoplasmic reticulum stress in chondrocytes.FEBS J.2801617–1629. 10.1111/febs.12170
72
YarrowJ. F.WhiteL. J.McCoyS. C.BorstS. E. (2010). Training augments resistance exercise induced elevation of circulating brain derived neurotrophic factor (BDNF).Neurosci. Lett.479161–165. 10.1016/j.neulet.2010.05.058
73
YudohK.van TrieuN.NakamuraH.Hongo-MasukoK.KatoT.NishiokaK. (2005). Potential involvement of oxidative stress in cartilage senescence and development of osteoarthritis: oxidative stress induces chondrocyte telomere instability and downregulation of chondrocyte function.Arthritis Res. Ther.7:R380.
Summary
Keywords
osteoarthritis, aerobic training, exercise, biomarkers, joint function
Citation
Martins JB, Mendonça VA, Aguiar GC, Fonseca SF, Santos JM, Tossige-Gomes R, Melo DS, Oliveira MX, Leite HR, Camargos ACR, Ferreira AJ, Coimbra CC, Poortmans J, Oliveira VC, Silva SB, Domingues TE, Bernardo-Filho M and Lacerda ACR (2019) Effect of a Moderate-Intensity Aerobic Training on Joint Biomarkers and Functional Adaptations in Rats Subjected to Induced Knee Osteoarthritis. Front. Physiol. 10:1168. doi: 10.3389/fphys.2019.01168
Received
14 June 2019
Accepted
29 August 2019
Published
18 September 2019
Volume
10 - 2019
Edited by
Leonardo Alexandre Peyré-Tartaruga, Federal University of Rio Grande do Sul, Brazil
Reviewed by
Júlio Cezar De Oliveira, Federal University of Mato Grosso, Brazil; Marli Maria Knorst, Federal University of Rio Grande do Sul, Brazil
Updates
Copyright
© 2019 Martins, Mendonça, Aguiar, Fonseca, Santos, Tossige-Gomes, Melo, Oliveira, Leite, Camargos, Ferreira, Coimbra, Poortmans, Oliveira, Silva, Domingues, Bernardo-Filho and Lacerda.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Ana Cristina Rodrigues Lacerda, lacerdaacr@gmail.com; lacerda.acr@ufvjm.edu.br
This article was submitted to Integrative Physiology, a section of the journal Frontiers in Physiology
Disclaimer
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.