RNA sequencing reveals target genes of temporomandibular joint osteoarthritis in rats after the treatment of low-intensity pulsed ultrasound

AbstractUltrasound stimulation is a type of mechanical stress, and low-intensity pulsed ultrasound (LIPUS) devices have been used clinically to promote fracture healing. However, it remains unclear which skeletal cells, in particular osteocytes or osteoblasts, primarily respond to LIPUS stimulation and how they contribute to fracture healing. To examine this, we utilized medaka, whose bone lacks osteocytes, and zebrafish, whose bone has osteocytes, as in vivo models. Fracture healing was accelerated by ultrasound stimulation in zebrafish, but not in medaka. To examine the molecular events induced by LIPUS stimulation in osteocytes, we performed RNA sequencing of a murine osteocytic cell line exposed to LIPUS. 179 genes reacted to LIPUS stimulation, and functional cluster analysis identified among them several molecular signatures related to immunity, secretion, and transcription. Notably, most of the isolated transcription-related genes were also modulated by LIPUS in vivo in zebrafish. However, expression levels of early growth response protein 1 and 2 (Egr1, 2), JunB, forkhead box Q1 (FoxQ1), and nuclear factor of activated T cells c1 (NFATc1) were not altered by LIPUS in medaka, suggesting that these genes are key transcriptional regulators of LIPUS-dependent fracture healing via osteocytes. We therefore show that bone-embedded osteocytes are necessary for LIPUS-induced promotion of fracture healing via transcriptional control of target genes, which presumably activates neighboring cells involved in fracture healing processes.

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Effectiveness of low-intensity pulsed ultrasound on osteoarthritis of the temporomandibular joint: A review

Annals of Biomedical Engineering ◽

10.1007/s10439-020-02540-x ◽

2020 ◽

Vol 48 (8) ◽

pp. 2158-2170

Author(s):

Eiji Tanaka ◽

Yao Liu ◽

Linze Xia ◽

Naoko Ogasawara ◽

Takuma Sakamaki ◽

...

Keyword(s):

Temporomandibular Joint ◽

Pulsed Ultrasound ◽

Low Intensity Pulsed Ultrasound ◽

Low Intensity

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Effects of low-intensity pulsed ultrasound (LIPUS) applied on the temporomandibular joint (TMJ) region on the functional treatment of class II malocclusion: A randomized controlled trial

Dental and Medical Problems ◽

10.17219/dmp/112321 ◽

2020 ◽

Vol 57 (1) ◽

pp. 53-60

Author(s):

Mohammad Osama Namera ◽

Ghiath Mahmoud ◽

Abdulaziz Abdulhadi ◽

Ahmad Burhan

Keyword(s):

Randomized Controlled Trial ◽

Temporomandibular Joint ◽

Controlled Trial ◽

Class Ii ◽

Functional Treatment ◽

Class Ii Malocclusion ◽

Pulsed Ultrasound ◽

Low Intensity Pulsed Ultrasound ◽

Low Intensity ◽

Randomized Controlled

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The Attenuating Effect of Low-Intensity Pulsed Ultrasound on Hypoxia-Induced Rat Chondrocyte Damage in TMJ Osteoarthritis Based on TMT Labeling Quantitative Proteomic Analysis

Frontiers in Pharmacology ◽

10.3389/fphar.2021.752734 ◽

2021 ◽

Vol 12 ◽

Author(s):

Sa Du ◽

Chao Liang ◽

Yujie Sun ◽

Bowen Ma ◽

Wenmo Gao ◽

...

Keyword(s):

Treatment Group ◽

Control Group ◽

Pulsed Ultrasound ◽

Condylar Cartilage ◽

Low Intensity Pulsed Ultrasound ◽

Network Analyses ◽

Low Intensity ◽

Hypoxic Conditions ◽

Oxygen Treatment ◽

Temporomandibular Joint Osteoarthritis

Temporomandibular joint osteoarthritis (TMJOA) is a degenerative disease with a complex and multifactorial etiology. An increased intrajoint pressure or weakened penetration can exacerbate the hypoxic state of the condylar cartilage microenvironment. Our group previously simulated the hypoxic environment of TMJOA in vitro. Low-intensity pulsed ultrasound (LIPUS) stimulation attenuates chondrocyte matrix degradation via a hypoxia-inducible factor (HIF) pathway-associated mechanism, but the mode of action of LIPUS is currently poorly understood. Moreover, most recent studies investigated the pathological mechanisms of osteoarthritis, but no biomarkers have been established for assessing the therapeutic effect of LIPUS on TMJOA with high specificity, which results in a lack of guidance regarding clinical application. Here, tandem mass tag (TMT)-based quantitative proteomic technology was used to comprehensively screen the molecular targets and pathways affected by the action of LIPUS on chondrocytes under hypoxic conditions. A bioinformatic analysis identified 902 and 131 differentially expressed proteins (DEPs) in the <1% oxygen treatment group compared with the control group and in the <1% oxygen + LIPUS stimulation group compared with the <1% oxygen treatment group, respectively. The DEPs were analyzed by gene ontology (GO), KEGG pathway and protein-protein interaction (PPI) network analyses. By acting on extracellular matrix (ECM)-associated proteins, LIPUS increases energy production and activates the FAK signaling pathway to regulate cell biological behaviors. DEPs of interest were selected to verify the reliability of the proteomic results. In addition, this experiment demonstrated that LIPUS could upregulate chondrogenic factors (such as Sox9, Collagen Ⅱ and Aggrecan) and increase the mucin sulfate content. Moreover, LIPUS reduced the hydrolytic degradation of the ECM by decreasing the MMP3/TIMP1 ratio and vascularization by downregulating VEGF. Interestingly, LIPUS improved the migration ability of chondrocytes. In summary, LIPUS can regulate complex biological processes in chondrocytes under hypoxic conditions and alter the expression of many functional proteins, which results in reductions in hypoxia-induced chondrocyte damage. ECM proteins such as thrombospondin4, thrombospondin1, IL1RL1, and tissue inhibitors of metalloproteinase 1 play a central role and can be used as specific biomarkers determining the efficacy of LIPUS and viable clinical therapeutic targets of TMJOA.

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The Optimal Regimen for the Treatment of Temporomandibular Joint Injury Using Low-Intensity Pulsed Ultrasound in Rats with Chronic Sleep Deprivation

BioMed Research International ◽

10.1155/2020/5468173 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Chao Liang ◽

Tao Yang ◽

Gaoyi Wu ◽

Jun Li ◽

Wei Geng

Keyword(s):

Sleep Deprivation ◽

Temporomandibular Joint ◽

Cartilage Damage ◽

Pulsed Ultrasound ◽

Condylar Cartilage ◽

Joint Injury ◽

Low Intensity Pulsed Ultrasound ◽

Low Intensity ◽

Optimal Regimen ◽

Chronic Sleep

Low-intensity pulsed ultrasound (LIPUS) is an emerging physical therapy for the treatment of early temporomandibular joint injury and has a good effect on promoting cartilage and subchondral bone tissue repair. However, the best LIPUS intensity and treatment duration remain unclear. This study is aimed at observing the preventive and therapeutic effects of different modes of LIPUS and at identifying the optimal LIPUS treatment regimen for temporomandibular joint injury. In the present study, rat models of temporomandibular joint injury were established using a chronic sleep deprivation (CSD) method, and the effect of LIPUS as intensities of 30, 45, and 60 mW/cm2 was observed at 7, 14, and 21 days. After CSD, the condylar cartilage of the rats demonstrated variable degrees of surface roughening, collagen fiber disarrangement or even partial exfoliation, decreased proteoglycan synthesis and cartilage thickness, decreased chondrocyte proliferation, decreased type 2 collagen (COL-2) expression, and increased matrix metalloproteinase- (MMP-) 3 expression at all three time points. When the rats with CSD received different intensities of LIPUS treatment, the pathological changes were alleviated to various extents. The groups receiving 45 mW/cm2 LIPUS showed the most significant relief of cartilage damage, and this significant effect was observed on days 14 and 21. These results demonstrated that LIPUS can effectively inhibit CSD-induced condylar cartilage damage in rats, and LIPUS treatment at an intensity of 45 mW/cm2 for at least 2 weeks is the optimal regimen for temporomandibular joint injury.

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