Low magnitude high frequency vibration accelerated cartilage degeneration but improved epiphyseal bone formation in anterior cruciate ligament transect induced osteoarthritis rat model

Low-frequency whole-body vibration can enhance cartilage degradation with slight changes in subchondral bone in mice with knee osteoarthritis and does not have any morphologic effect on normal joints

PURPOSES

To evaluate the effects of low frequency whole-body vibration (WBV) on degeneration of articular cartilage and subchondral bone in mice with destabilization of the medial meniscus (DMM)induced osteoarthritis(OA) and mice with normal knee.

METHODS

Ten-week-old C57BL/6J male mice received DMM on right knees, while the left knees performed sham operation. There were six groups: DMM, SHAM DMM, DMM+WBV,SHAM DMM+WBV, DMM+ NON-WBV and SHAM DMM+NON-WBV. After four weeks, the knees were harvested from the DMM and SHAM DMM group. The remaining groups were treated with WBV (10 Hz) or NON-WBV. Four weeks later, the knees were harvested. Genes, containing Aggrecan(Acan) and CollagenⅡ(Col2a1), Matrix Metalloproteinases 3 and 13(MMP3,13), TNFα and IL6, were measured and staining was also performed. OA was graded with OARSI scores, and tibial plateaubone volume to tissue volume ratio(BV/TV), bone surface area to bone volume ratio (BS/BV), trabecular number(Tb.N) and trabecular thickness separation(TS) between groups were analyzed.

RESULTS

Increased OARSI scores and cartilage degradation were observed after WBV. BV/TV, Tb.N and TS were not significant between the groups. Significant reductions were observed in MMP3, MMP13, Col2a1, Acan, TNFα and IL6 in the DMM+WBV compared to SHAM DMM+WBV group. BV/TV, BS/BV, Tb.N, TS and OARSI scores were not significantly changed in the left knees. IL6 expression in the SHAM DMM+WBV group was significantly increased compared with the SHAM DMM+ NON-WBV group, while Col2a1, Acan and MMP13 expression decreased.

CONCLUSION

WBV accelerated cartilage degeneration and caused slight changes in subchondral bone in a DMM-induced OA model. WBV had no morphologic effect on normal joints.

Induced Models of Osteoarthritis in Animal Models: A Systematic Review

The most common induction methods for OA are mechanical, surgical and chemical. However, there is not a gold standard in the choice of OA animal models, as different animals and induction methods are helpful in different contexts. Reporting the latest evidence and results in the literature could help researchers worldwide to define the most appropriate indication for OA animal-model development. This review aims to better define the most appropriate animal model for various OA conditions. The research was conducted on the following literature databases: Medline, Embase, Cinahl, Scopus, Web of Science and Google Scholar. Studies reporting cases of OA in animal models and their induction from January 2010 to July 2021 were included in the study and reviewed by two authors. The literature search retrieved 1621 articles, of which 36 met the selection criteria and were included in this review. The selected studies included 1472 animals. Of all the studies selected, 8 included information about the chemical induction of OA, 19 were focused on mechanical induction, and 9 on surgical induction. Nevertheless, it is noteworthy that several induction models, mechanical, surgical and chemical, have been proven suitable for the induction of OA in animals.

Low-Frequency Vibration Promotes Tumor Necrosis Factor-α Production to Increase Cartilage Degeneration in Knee Osteoarthritis

OBJECTIVE

Low-frequency vibration accelerates cartilage degeneration in knee osteoarthritis (KOA) rat model. In this article, we investigated whether whole-body vibration (WBV) increases cartilage degeneration by regulating tumor necrosis factor-α (TNF-α) in KOA.

DESIGN

Proteomics analysis was used to filter candidate protein from synovial fluid (SF) in KOA people after WBV. Enzyme-linked immunosorbent assay (ELISA) was used to estimate changes in TNF-α levels in SF. The C57 mice and TNF-α knock-out mice were sacrificed for the KOA model and WBV intervention. The cartilage was tested by ELISA, histology, terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL), immunohistochemistry, and reverse transcriptase polymerase chain reaction. Luciferase activity test in vitro study was conducted to confirm the relationship between TNF-α and the candidate protein.

RESULTS

Differentially expressed proteins were enriched in the glycolytic process, glucose catabolic, and regulation of interleukin-8 (IL-8) secretion processes. Phosphoglycerate kinase, triosephosphate isomerase 1, T cell immunoglobulin- and mucin-domain-containing molecules 2, fumarylacetoacetate hydrolase (FAH), and TNF were the hub node. TNF-α expression increased in SF after WBV (P < 0.05). The cartilage was more degenerated in the TNF-α^-/- mice group compared to controls. A significant change was observed in collagen II and FAH (P < 0.05). TNF-α expression improved in C57 mice (P < 0.05). Apoptosis of chondrocytes was inhibited in TNF-α^-/- mice by the TUNEL test. Luciferase activity significantly increased in TNF-α + FAH-Luc cells (P < 0.05).

CONCLUSION

A novel mechanism underlying WBV-triggered cartilage degeneration was found in KOA that demonstrated the critical regulatory function of TNF-α and FAH during WBV.

The Application of Whole-Body Vibration Training in Knee Osteoarthritis

With the gradual increase of the aging population in Chinese society, the incidence of knee osteoarthritis showed an increasing trend. However, there are very few practical solutions for it. As a novel neuromuscular training technique, whole-body vibration training has become a candidate for treating knee osteoarthritis. In this review, we firstly elaborated on the mode of action and influence factors of the whole-body vibration training. Next, we summarized its effects in knee osteoarthritis, including improving knee function and some uncertain muscle function and proprioception effects. Next, we also summarized its possible mechanisms, including improving bone microstructure, delaying articular cartilage degeneration, modulating inflammatory cells and inflammatory factors. Then, we summarized the clinical effectiveness of whole-body vibration training by analyzing some clinical randomized controlled trials. Finally, based on the above summary, we analyzed and listed the limitations of whole-body vibration training in treating knee osteoarthritis and found the shortcomings in the existing studies. This review provides ideas for the future application of whole-body vibration training in the treatment of knee osteoarthritis.

Fibrinolysis as a target to enhance osteoporotic fracture healing by vibration therapy in a metaphyseal fracture model

Aims

Fibrinolysis plays a key transition step from haematoma formation to angiogenesis and fracture healing. Low-magnitude high-frequency vibration (LMHFV) is a non-invasive biophysical modality proven to enhance fibrinolytic factors. This study investigates the effect of LMHFV on fibrinolysis in a clinically relevant animal model to accelerate osteoporotic fracture healing.

Methods

A total of 144 rats were randomized to four groups: sham control; sham and LMHFV; ovariectomized (OVX); and ovariectomized and LMHFV (OVX-VT). Fibrinolytic potential was evaluated by quantifying fibrin, tissue plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1) along with healing outcomes at three days, one week, two weeks, and six weeks post-fracture.

Results

All rats achieved healing, and x-ray relative radiopacity for OVX-VT was significantly higher compared to OVX at week 2. Martius Scarlet Blue (MSB) staining revealed a significant decrease of fibrin content in the callus in OVX-VT compared with OVX on day 3 (p = 0.020). Mean tPA from muscle was significantly higher for OVX-VT compared to OVX (p = 0.020) on day 3. Mechanical testing revealed the mean energy to failure was significantly higher for OVX-VT at 37.6 N mm (SD 8.4) and 71.9 N mm (SD 30.7) compared with OVX at 5.76 N mm (SD 7.1) (p = 0.010) and 17.7 N mm (SD 11.5) (p = 0.030) at week 2 and week 6, respectively.

Conclusion

Metaphyseal fracture healing is enhanced by LMHFV, and one of the important molecular pathways it acts on is fibrinolysis. LMHFV is a promising intervention for osteoporotic metaphyseal fracture healing. The improved mechanical properties, acceleration of fracture healing, and safety justify its role into translation to future clinical studies.

Cite this article: Bone Joint Res 2021;10(1):41–50.

Salviae miltiorrhizae radix and puerariae lobatae radix herbal formula improves circulation, vascularization and gait function in a peripheral arterial disease rat model

ETHNOPHARMACOLOGICAL RELEVANCE

DG is a herbal formula, containing the root of Salvia miltiorrhiza Bunge (Danshen) and the root of Pueraria lobate (Willd.) Ohwi (Gegen), has a history of usage in China for cardiovascular protection and anti-atherosclerosis.

AIM OF THE STUDY

The present study aims to determine the beneficial effect of DG on the hind-limb ischemia rat model which mimics peripheral arterial disease (PAD) and its vasodilative effect on isolated femoral artery.

MATERIALS AND METHODS

The vasodilatory effects were assessed by contractile responses to DG in the isolated femoral artery and its underlying mechanisms were evaluated by the involvement of endothelium, potassium channel and calcium channel. For hind-limb ischemia study, treatment outcomes were assessed by evaluating hind-limb blood flow, functional limb recovery, muscle histology and angiogenesis.

RESULTS

Our results demonstrated positive dose-dependent vasodilatory response to DG via an endothelium-independent mechanism that involved inwardly rectifying K⁺ channels and Ca²⁺ channels. We also demonstrated significant improvement in blood perfusion and micro-vessel density in the ischemic limb and positive effects in functional limb recovery.

CONCLUSION

In conclusion, our study supported the potential use of DG as a novel treatment for symptomatic PAD.

Effect of whole body vibration on HIF-2α expression in SD rats with early knee osteoarthritis

INTRODUCTION

To investigate the effect of different frequencies of whole body vibration (WBV) on articular cartilage of early knee osteoarthritis (OA) rats and determine whether WBV would influence the pathway of hypoxia-inducible factor-2α (HIF-2α) regulation-related genes after 8 weeks of treatment.

MATERIALS AND METHODS

Forty 8-week-old OA rats were divided into five groups: sham control (SC); high frequency 60 Hz (HV₁); high frequency 40 Hz (HV₂); middle frequency 20 Hz (MV) and low frequency 10 Hz (LV). WBV (0.3 g) treatment was given 40 min/day and 5 days/week. After 8 weeks, rats were killed and knees were harvested. OA grading score: Osteoarthritis Research Society International (OARSI), and the expression of related genes: interleukin-1β (IL-1β), HIF-2α, matrix metalloproteinases-13 (MMP-13), and collagen type II alpha 1 (COL2A1), at both mRNA and protein levels were analyzed.

RESULTS

After 8 weeks of WBV, our data showed that lower frequency (10 Hz) was more effective than the higher ones, yet they all suggested that WBV alleviates the erosion of knee articular cartilage in early OA. The expression of IL-1β, HIF-2α and MMP-13 decreased with frequency and reached the lowest level at 10 Hz, the expression of COL2A1 increased with frequency and reached the highest level at 10 Hz.

CONCLUSIONS

This study demonstrates that WBV could alleviate the degeneration of knee joints in an early OA rat model. WBV regulates related gene expression at both mRNA and protein levels. HIF-2α could be a therapeutic target. The effect of WBV is frequency dependent; the lower frequency shows better effects.

MicroRNA-375 exacerbates knee osteoarthritis through repressing chondrocyte autophagy by targeting ATG2B

Objective: This study aimed to explore the underlying mechanism of miR-375 in exacerbating osteoarthritis (OA).

Results: MiR-375 expression were upregulated in OA cartilage tissues, whereas ATG2B expression was decreased. MiR-375 targeted ATG2B 3’ UTR and inhibited its expression in the chondrocytes, and then suppressed autophagy and promoted endoplasmic reticulum stress (ERs). The apoptosis rate of chondrocytes was increased after being transfected with miR-375 mimics. In vivo results further verified that inhibition of miR-375 could relieve OA-related symptoms.

Conclusion: miR-375 can inhibit the expression of ATG2B in chondrocytes, suppress autophagy and promote the ERs. It suggests that miR-375 could be considered to be a key therapy target for OA.

Methods: Differential expression analyses for mRNA and miRNA microarray datasets from ArrayExpress were performed. MiR-375 and ATG2B expressions in cartilage tissues were detected by qRT-PCR. Dual luciferase assay was applied to verify the targeting relationship between ATG2B and miR-375. In vitro, the role of miR-375 on chondrocyte autophagy and ERs was investigated by western blot and immunofluorescence. The apoptotic rate was quantified by flow cytometry. In vivo, OA mice model was established, HE and Safranin O and Fast Green staining, as well as the OARSI and modified Mankin scores, were applied to measure the OA cartilage damage severity.

Interaction between body composition and impact-related parameters in male and female heel-toe runners

BACKGROUND

Bone fatigue resistance and more generally the ability to dissipate the stress sustained in dynamic tasks are partly affected by tissue properties. Men and women demonstrate substantial differences in body composition.

RESEARCH QUESTION

To assess whether gender, as a function of body composition, affects impact-related parameters in running.

METHODS

A qualitative study has been conducted. Twelve females and eighteen males performed four 2-min running trials at 2.8 m∙s^-1, 3.3 m∙s^-1, 3.9 m∙s^-1, and 4.4 m∙s^-1 while recording axial and transverse tibial acceleration. Peak acceleration and power spectral density within the impact-related frequency range (vibration content) were measured. Bone mineral content, fat mass, lean mass, and muscle mass were assessed using an impedance meter. Two-way (gender × speed) ANOVAs were computed. Multiple linear regressions were then used to assess the magnitude of the effect of body composition indicators on impact-related parameters.

RESULTS

Significant gender and speed effects were observed. Females and high running speeds were associated with greater peak acceleration and vibration content at the tibia. Small interactions were observed between muscle mass and axial peak acceleration and vibration content, and between bone mineral content and transverse peak acceleration and vibration content, and axial vibration content.

SIGNIFICANCE

Women demonstrated greater mechanical stress than men during running. High mechanical stress was associated with low bone mineral content and muscle mass. These findings may have implications in the prevention and management of bone overuse injuries in runners.

Low-intensity vibration increases cartilage thickness in obese mice

Obesity is associated with an elevated risk of osteoarthritis (OA). We examined here whether high fat diet administered in young mice, compromised the attainment of articular cartilage thickness. Further, we sought to determine if low-intensity vibration (LIV) could protect the retention of articular cartilage in a mouse model of diet-induced obesity. Five-week-old, male, C57BL/6 mice were separated into three groups (n = 10): Regular diet (RD), High fat diet (HF), and HF + LIV (HFv; 90 Hz, 0.2g, 30 min/d, 5 d/w) administered for 6 weeks. Additionally, an extended HF diet study was run for 6 months (LIV at 15 m/d). Articular cartilage and subchondral bone morphology, and sulfated GAG content were quantified using contrast agent enhanced μCT and histology. Gene expression within femoral condyles was quantified using real-time polymerase chain reaction. Contrary to our hypothesis, HF cartilage thickness was not statistically different from RD. However, LIV increased cartilage thickness compared to HF, and the elevated thickness was maintained when diet and LIV were extended into adulthood. RT-PCR analysis showed a reduction of aggrecan expression with high fat diet, while application of LIV reduced the expression of degradative MMP-13. Further, long-term HF diet resulted in subchondral bone thickening, compared to RD, providing early evidence of OA pathology-LIV suppressed the thickening, such that levels were not significantly different from RD. These data suggest that dynamic loading, via LIV, protected the retention of cartilage thickness, potentially resulting in joint surfaces better suited to endure the risks of elevated loading that parallel obesity. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:751-759, 2018.

Low-Magnitude High-Frequency Vibration Accelerated the Foot Wound Healing of n5-streptozotocin-induced Diabetic Rats by Enhancing Glucose Transporter 4 and Blood Microcirculation

Delayed wound healing is a Type 2 diabetes mellitus (DM) complication caused by hyperglycemia, systemic inflammation, and decreased blood microcirculation. Skeletal muscles are also affected by hyperglycemia, resulting in reduced blood flow and glucose uptake. Low Magnitude High Frequency Vibration (LMHFV) has been proven to be beneficial to muscle contractility and blood microcirculation. We hypothesized that LMHFV could accelerate the wound healing of n5-streptozotocin (n5-STZ)-induced DM rats by enhancing muscle activity and blood microcirculation. This study investigated the effects of LMHFV in an open foot wound created on the footpad of n5-STZ-induced DM rats (DM_V), compared with no-treatment DM (DM), non-DM vibration (Ctrl_V) and non-DM control rats (Ctrl) on Days 1, 4, 8 and 13. Results showed that the foot wounds of DM_V and Ctrl_V rats were significantly reduced in size compared to DM and Ctrl rats, respectively, at Day 13. The blood glucose level of DM_V rats was significantly reduced, while the glucose transporter 4 (GLUT4) expression and blood microcirculation of DM_V rats were significantly enhanced in comparison to those of DM rats. In conclusion, LMHFV can accelerate the foot wound healing process of n5-STZ rats.

Different doses of strontium ranelate and mechanical vibration modulate distinct responses in the articular cartilage of ovariectomized rats

OBJECTIVE

To investigate the effects of different strontium ranelate (SrR) doses alone or in combination with low-intensity and high-frequency mechanical vibration (MV) on articular cartilage in ovariectomized rats.

DESIGN

Fifty 6-month-old female Wistar rats underwent ovariectomy (OVX) and after 3 months were divided into: control group (Control); SrR 300 mg/kg/day (SrR300); SrR 625 mg/kg/day (SrR625); MV; SrR 625 mg/kg/day plus MV (SrR625 + MV). The vehicle and the SrR were administered by gavage 7 days/week and vibration (0.6 g/60 Hz) was performed for 20 min/day, 5 days/week. Bone mineral density (BMD) and body composition were evaluated by densitometry. Changes in cartilage were assessed 90 days after treatment by histomorphometry; immunohistochemistry analysis evaluating cell death (caspase-3), tumor necrosis factor-α (TNF-α), metalloproteinase 9 (MMP-9) and type II collagen; Osteoarthritis Research Society International (OARSI) grading system and glycosaminoglycans (GAGs) analyses.

RESULTS

SrR-treated groups exhibited a lower OARSI grade, a smaller number of chondrocyte clusters, increased levels of chondroitin sulfate (CS) and decreased expression of caspase-3. Additionally, compared to all the groups, SrR300 exhibited increased levels of hyaluronic acid (HA). Vibration applied alone or in combination accelerated cartilage degradation, as demonstrated by increased OARSI grade, reduced number of chondrocytes, increased number of clusters, elevated expression of type II collagen and cell death, and was accompanied by decreased amounts of CS and HA; however, MV alone was able to reduce MMP-9.

CONCLUSIONS

SrR and vibration modulate distinct responses in cartilage. Combined treatment accelerates degeneration. In contrast, SrR treatment at 300 mg/kg/day attenuates osteoarthritis (OA) progression, improving cartilage matrix quality and preserving cell viability in ovariectomized rats.

Effect of low-magnitude different-frequency whole-body vibration on subchondral trabecular bone microarchitecture, cartilage degradation, bone/cartilage turnover, and joint pain in rabbits with knee osteoarthritis

Backgroud

Whole-body vibration(WBV) has been suggested for the prevention of subchondral bone loss of knee osteoarthritis (OA) . This study examined the effects of different frequency of whole-body vibration on subchondral trabecular bone microarchitecture, cartilage degradation and metabolism of the tibia and femoral condyle bone, and joint pain in an anterior cruciate ligament transection (ACLT)–induced knee osteoarthritisrabbit model.

Method

Ninety adult rabbits were divided into six groups: all groups received unilateral ACLT; Group 1, ACLT only; Group 2, 5 Hz WBV; Group 3, 10 Hz WBV; Group 4, 20 Hz WBV; Group 5, 30 Hz WBV; and Group 6, 40 Hz WBV. Pain was tested via weight-bearing asymmetry. Subchondral trabecular bone microarchitecture was examined using in vivo micro-computed tomography. Knee joint cartilage was evaluated by gross morphology, histology, and ECM gene expression level (aggrecan and type II collagen [CTX-II]). Serum bone-specific alkaline phosphatase, N-mid OC, cartilage oligometric protein, CPII, type I collagen, PIIANP, G1/G2 aggrecan levels, and urinary CTX-II were analyzed.

Results

After 8 weeks of low-magnitude WBV, the lower frequency (10 Hz and 20 Hz) WBV treatment decreased joint pain and cartilage resorption, accelerated cartilage formation, delayed cartilage degradation especially at the 20 Hz regimen. However, the higher frequencies (30 Hz and 40 Hz) had worse effects, with worse limb function and cartilage volume as well as higher histological scores and cartilage resorption. In contrast, both prevented loss of trabeculae and increased bone turnover. No significant change was observed in the 5 Hz WBV group.

Conclusion

Our data demonstrate that the lower frequencies (10 Hz and 20 Hz) of low-magnitude WBV increased bone turnover, delayed cartilage degeneration, and caused a significant functional change of the OA-affected limb in ACLT-induced OA rabbit model but did not reverse OA progression after 8 weeks of treatment.

The characterization of a full-thickness excision open foot wound model in n5-streptozotocin (STZ)-induced type 2 diabetic rats that mimics diabetic foot ulcer in terms of reduced blood circulation, higher C-reactive protein, elevated inflammation, and reduced cell proliferation

Delayed foot wound healing is a major complication attributed to hyperglycemia in type 2 diabetes mellitus (DM) patients, and these wounds may develop into foot ulcers. There are at least two types of DM wound models used in rodents to study delayed wound healing. However, clinically relevant animal models are not common. Most models use type 1 DM rodents or wounds created on the back rather than on the foot. An open full-thickness excision wound on the footpad of type 2 DM rats is more clinically relevant, but such a model has not yet been characterized systematically. The objective of this study was to investigate and characterize how DM affected a full-thickness excision open foot wound in n5-streptozotocin (n5-STZ)-induced type 2 DM rats. We hypothesized that elevated inflammation, reduced blood circulation, and cell proliferation due to hyperglycemia could delay the wound healing of DM rats. The wounds of DM rats were compared with those of non-DM rats (Ctrl) at Days 1 and 8 post wounding. The wound healing process of the DM rats was significantly delayed compared with that of the Ctrl rats. The DM rats also had higher C-reactive protein (CRP) and lower blood circulation and proliferating cell nuclear antigen (PCNA) in DM wounds. This confirmed that elevated inflammation and reduced blood flow and cell proliferation delayed foot wound healing in the n5-STZ rats. Hence, this open foot wound animal model provides a good approach to study the process of delayed wound healing.

Repeated exposure to high-frequency low-amplitude vibration induces degeneration of murine intervertebral discs and knee joints

OBJECTIVE

High-frequency, low-amplitude whole-body vibration (WBV) is being used to treat a range of musculoskeletal disorders; however, there is surprisingly limited knowledge regarding its effect(s) on joint tissues. This study was undertaken to examine the effects of repeated exposure to WBV on bone and joint tissues in an in vivo mouse model.

METHODS

Ten-week-old male mice were exposed to vertical sinusoidal vibration under conditions that mimic those used clinically in humans (30 minutes per day, 5 days per week, at 45 Hz with peak acceleration at 0.3g). Following WBV, skeletal tissues were examined by micro-computed tomography, histologic analysis, and immunohistochemistry, and gene expression was quantified using real-time polymerase chain reaction.

RESULTS

Following 4 weeks of WBV, intervertebral discs showed histologic hallmarks of degeneration in the annulus fibrosus, disruption of collagen organization, and increased cell death. Greater Mmp3 expression in the intervertebral disc, accompanied by enhanced collagen and aggrecan degradation, was found in mice exposed to WBV as compared to controls. Examination of the knee joints after 4 weeks of WBV revealed meniscal tears and focal damage to the articular cartilage, changes resembling osteoarthritis. Moreover, mice exposed to WBV also demonstrated greater Mmp13 gene expression and enhanced matrix metalloproteinase-mediated collagen and aggrecan degradation in articular cartilage as compared to controls. No changes in trabecular bone microarchitecture or density were detected in the proximal tibia.

CONCLUSION

Our experiments reveal significant negative effects of WBV on joint tissues in a mouse model. These findings suggest the need for future studies of the effects of WBV on joint health in humans.