Efficacy of hyaluronic acid injections in patients with osteoarthritis of the temporomandibular joint. A comparative study

S-propargyl-cysteine attenuates temporomandibular joint osteoarthritis by regulating macrophage polarization via Inhibition of JAK/STAT signaling

BACKGROUND

Temporomandibular joint osteoarthritis (TMJ-OA) is a disease characterized by cartilage degradation and synovial inflammation, with limited effective treatment currently. Synovial macrophage polarization is pivotal in TMJ-OA progression, making it a promising therapeutic aspect. This study investigated the effects of S-propargyl-cysteine (SPRC), an endogenous H2S donor, on macrophage polarization and its therapeutic potential in alleviating TMJ-OA.

METHODS

A MIA-induced TMJ-OA rat model and LPS-stimulated RAW264.7 macrophages were employed to evaluate the effects of SPRC in vivo and in vitro. TMJ bone and cartilage were analyzed via micro-CT and histological methods, while macrophage polarization markers expression were assessed via RT-qPCR, western blot, and immunofluorescence. RNA sequencing was performed on macrophages, and the JAK2/STAT3 signaling pathway was validated using the JAK2-specific inhibitor AG490. The direct effects of SPRC on rat primary condylar chondrocytes were examined by evaluating ECM synthesis and degradation. Co-culture experiments further assessed macrophage-chondrocyte interactions.

RESULTS

SPRC significantly alleviated cartilage and bone damage in the TMJ-OA rat model, as demonstrated by improved bone volume and cartilage structure. SPRC reduced pro-inflammatory M1 macrophage infiltration and enhanced anti-inflammatory M2 macrophage polarization. SPRC effectively inhibited the JAK2/STAT3, leading to reduction of inflammatory markers, including TNF-α, IL-6, and iNOS. Co-culture experiments revealed that SPRC-treated macrophage-conditioned medium improved chondrocyte metabolic activity and restored ECM integrity.

CONCLUSIONS

SPRC-modulated macrophage polarization alleviates TMJ-OA via JAK/STAT downregulation, thereby reducing synovial inflammation and cartilage degradation. These findings position SPRC as a promising therapeutic candidate for TMJ-OA and provide insights into novel strategies targeting macrophage polarization and synovium-cartilage crosstalk.

G-protein-coupled estrogen receptor 30 regulation of signaling downstream of protein kinase Cε mediates sex dimorphism in hyaluronan-induced antihyperalgesia

ABSTRACT

High molecular weight hyaluronan (HMWH) inhibits hyperalgesia induced by diverse pronociceptive inflammatory mediators and their second messengers, in rats of both sexes. However, the hyperalgesia induced by ligands at 3 pattern recognition receptors, lipopolysaccharide (a toll-like receptor 4 agonist), lipoteichoic acid (a toll-like receptor 2/6 agonist), and nigericin (a NOD-like receptor family, pyrin domain containing 3 activator), and oxaliplatin and paclitaxel chemotherapy-induced peripheral neuropathy are only attenuated in males. After gonadectomy or intrathecal administration of an antisense to G-protein-coupled estrogen receptor 30 (GPER) mRNA, HMWH produces antihyperalgesia in females. In nociceptors cultured from rats that had been treated with oxaliplatin, HMWH reverses nociceptor sensitization from male and GPER antisense-treated female, but not from gonad intact females. G-protein-coupled estrogen receptor-dependent sex dimorphism for HMWH-induced antihyperalgesia was also observed for the prolongation of prostaglandin E 2 (PGE 2 )-induced hyperalgesia in primed nociceptors. While in primed rats, HMWH inhibits early, protein kinase A-dependent hyperalgesia, 30 minutes post PGE 2 injection, in both sexes; measured 4 hours post-PGE 2 , HMWH inhibits the protein kinase Cε (PKCε)-dependent prolongation of PGE 2 hyperalgesia only in males and GPER antisense-treated females. In females, hyperalgesia induced by PKCε agonist, ψεRACK, in control but not in primed nociceptors, was inhibited by HMWH. Inhibitors of 2 GPER second messengers, extracellular-regulated kinase 1/2 and nonreceptor tyrosine kinase, also unmasked HMWH antihyperalgesia in females with oxaliplatin chemotherapy-induced peripheral neuropathy, a condition in which nociceptors are primed as well as sensitized. Our results support GPER-dependent sex dimorphism in HMWH-induced antihyperalgesia for pain induced by pattern recognition receptor agonists, and chronic inflammatory and neuropathic pain, mediated by changes in signaling downstream of PKCε in primed nociceptors.

The Temporomandibular Joint and the Human Body: A New Perspective on Cross Talk

Background: As a unique joint that facilitates the articulation of the upper and lower jaws, the temporomandibular joint (TMJ) is concerned with several critical functions, such as speech and mastication. Pain that can become incapacitating is a result of temporomandibular disorders (TMDs), which are complex disorders affecting the masticatory muscles and the TMJ. Several anomalies and TMDs have an interdisciplinary relationship. Complementary and concurrent disorders may be caused by occlusal anomalies, psychological disorders, and changes in spine posture. Methods: This article examines the clinical characteristics of TMDs, their classification, their etiological factors, and the impact of TMJ disorders on the human body with reference to their anatomies and histological structures. Results: The clinical picture of some TMJ pathologies may be unknown, so certain biomarkers, such as cytokines, may be useful for an accurate diagnosis as they are frequently seen in TMJ disorders. Furthermore, novel therapeutic approaches that target pro-inflammatory cytokines and treat TMDs by using tissue engineering and regenerative medicine while permitting TMJ cartilage and bone regeneration may offer numerous benefits that require clinical translation. Conclusions: Implementation of recent modalities such as microvesicles and platelet-rich plasma in growth factors may provide a promising approach to enhance bone formation. In addition, we target different biological markers that give insights into the introduction of new pharmaceutical agents for therapy.

Intraarticular injections of hyaluronic acid in arthrocentesis and arthroscopy as a treatment of temporomandibular joint disorders: A systematic review

OBJECTIVE

To evaluate the benefits of hyaluronic acid intraarticular injection (HA IAI), in conjunction with minimally invasive surgery (arthrocentesis or arthroscopy), as a therapeutic option for temporomandibular joint disorders.

METHODS

An electronic search in PubMed, Cochrane Library, and Scopus databases was conducted in order to answer the following PICOS question: "In clinical trials with patients treated with arthroscopy or arthrocentesis, did the subsequent use of HA IAI provide a better control of postoperative pain and temporomandibular joint function compared to those patients who did not receive it?"

RESULTS

Following PRISMA criteria, six randomized controlled clinical trials were selected. HA IAI showed significant differences in terms of pain reduction in three of them and improvement of mandibular function in two, compared to the control group.

CONCLUSION

Based on scientific evidence, the level of recommendation found regarding this type of intervention is type B (recommendation based on inconsistent or limited-quality patient-oriented evidence).

Topical coapplication of hyaluronan with transdermal drug delivery enhancers attenuates inflammatory and neuropathic pain

ABSTRACT

We have previously shown that intradermal injection of high-molecular-weight hyaluronan (500-1200 kDa) produces localized antihyperalgesia in preclinical models of inflammatory and neuropathic pain. In the present experiments, we studied the therapeutic effect of topical hyaluronan, when combined with each of 3 transdermal drug delivery enhancers (dimethyl sulfoxide [DMSO], protamine or terpene), in preclinical models of inflammatory and neuropathic pain. Topical application of 500 to 1200 kDa hyaluronan (the molecular weight range used in our previous studies employing intradermal administration), dissolved in 75% DMSO in saline, markedly reduced prostaglandin E 2 (PGE 2 ) hyperalgesia, in male and female rats. Although topical 500- to 1200-kDa hyaluronan in DMSO vehicle dose dependently, also markedly, attenuated oxaliplatin chemotherapy-and paclitaxel chemotherapy-induced painful peripheral neuropathy (CIPN) in male rats, it lacked efficacy in female rats. However, following ovariectomy or intrathecal administration of an oligodeoxynucleotide antisense to G-protein-coupled estrogen receptor (GPR30) mRNA, CIPN in female rats was now attenuated by topical hyaluronan. Although topical coadministration of 150 to 300, 300 to 500, or 1500 to 1750 kDa hyaluronan with DMSO also attenuated CIPN, a slightly lower-molecular-weight hyaluronan (70-120 kDa) did not. The topical administration of a combination of hyaluronan with 2 other transdermal drug delivery enhancers, protamine and terpene, also attenuated CIPN hyperalgesia, an effect that was more prolonged than with DMSO vehicle. Repeated administration of topical hyaluronan prolonged the duration of antihyperalgesia. Our results support the use of topical hyaluronan, combined with chemically diverse nontoxic skin penetration enhancers, to induce marked antihyperalgesia in preclinical models of inflammatory and neuropathic pain.

Comparison of Four Treatment Protocols with Intra-Articular Medium Molecular Weight Hyaluronic Acid in Induced Temporomandibular Osteoarthritis: An Experimental Study

The aim was to compare the effect between a single intra-articular infiltration (1i) and two infiltrations (2i) of medium molecular weight hyaluronic acid (MMW-HA) of high viscosity (HV) and low viscosity (LV) on the histopathological characteristics of temporomandibular joint (TMJ) osteoarthritis (OA) induced in rabbits. An experimental study was conducted on Oryctolagus cuniculus rabbits, including 42 TMJs, distributed between (1) TMJ-C, control group; (2) TMJ-OA, group with OA; (3) TMJ-OA-wt, group with untreated OA; (4) group treated with HA-HV-1i; (5) group treated with HA-HV-2i; (6) group treated with HA-LV-1i; and (7) group treated with HA-LV-2i. The results were evaluated using the Osteoarthritis Research Society International (OARSI) scale and descriptive histology considering the mandibular condyle (MC), the articular disc (AD), and the mandibular fossa (MF). The Kruskal-Wallis test was used for the statistical analysis, considering p < 0.05 significant. All treated groups significantly decreased the severity of OA compared to the TMJ-OA-wt group. The HA-HV-2i group showed significant differences in the degree of OA from the TMJ-OA group. The degree of OA in the HA-HV-2i group was significantly lower than in the HA-LV-1i, HA-LV-2i, and HA-HV-1i groups. The protocol that showed better results in repairing the joint was HA-HV-2i. There are histological differences depending on the protocol of the preparation used: two infiltrations seem to be better than one, and when applying two doses, high viscosity shows better results.

Near-Infrared Light-Activated Mesoporous Polydopamine for Temporomandibular Joint Osteoarthritis Combined Photothermal-Chemo Therapy

The treatments generally employed for temporomandibular joint osteoarthritis (TMJOA) involve physical therapy and chemotherapy, etc., whose therapeutic efficacies are impaired by the side effects and suboptimal stimulus responsiveness. Although the intra-articular drug delivery system (DDS) has shown effectiveness in addressing osteoarthritis, there is currently little reported research regarding the use of stimuli-responsive DDS in managing TMJOA. Herein, we prepared a novel near-infrared (NIR) light-sensitive DDS (DS-TD/MPDA) by using mesoporous polydopamine nanospheres (MPDA) as NIR responders and drug carriers; diclofenac sodium (DS) as the anti-inflammatory medication; and 1-tetradecanol (TD) with a phase-inversion temperature of 39 °C as the drug administrator. Upon exposure to 808 nm NIR laser, DS-TD/MPDA could raise the temperature up to the melting point of TD through photothermal conversion, and intelligently trigger DS release. The resultant nanospheres exhibited an excellent photothermal effect and effectively controlled the release of DS through laser irradiation to accommodate the multifunctional therapeutic effect. More importantly, the biological evaluation of DS-TD/MPDA for TMJOA treatment was also performed for the first time. The experiments' results demonstrated that DS-TD/MPDA displayed a good biocompatibility in vitro and in vivo during metabolism. After injection into the TMJ of rats afflicted with TMJOA induced by unilateral anterior crossbite for 14 days, DS-TD/MPDA could alleviate the deterioration of TMJ cartilage, thus ameliorating osteoarthritis. Therefore, DS-TD/MPDA could be a promising candidate for photothermal-chemotherapy for TMJOA.

EFFECTIVENESS OF INTRA-ARTICULAR INJECTIONS OF SODIUM HYALURONATE, CORTICOSTEROIDS, PLATELET-RICH PLASMA ON TEMPOROMANDIBULAR JOINT OSTEOARTHRITIS: A SYSTEMATIC REVIEW AND NETWORK META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS

OBJECTIVE

To compare the efficacy of Intra-articular injections of corticosteroids (CCS), hyaluronic acid (HA), and platelet-rich plasma (PRP) on temporomandibular joint osteoarthritis.

METHODS

Studies were identified from PubMed, Embase and Cochrane Central Register of Controlled Trials, ClinicalTrials.gov with date up to January 15, 2022. Randomized controlled trials included were the studies of patients with temporomandibular joint osteoarthritis who had intra-articular treatment with CCS, HA, PRP, placebo and follow-up assessing temporomandibular joint function in target outcome variables. The primary outcome was temporomandibular joint pain. The secondary outcomes were maximal mouth opening (mm), and lateral movement to the affected side (mm). This study is registered with PROSPERO, number CRD42021270914.

RESULTS

Nine randomized controlled trials involving 316 patients were included. For primary pain outcome, no significance was detected when CCS, HA and PRP were compared with placebo by both short- (3-6 months) and long-term (>12 months) follow-up. Relatively, the top ranking of which was PRP in the long-term (Mean Difference, -0.23 [95% CI, -2.49 to 2.04]). In addition, these injectables did not significantly outperform placebo by evaluating secondary functional outcomes (maximal mouth opening and lateral movement) with the same follow-up. Subgroup analyses showed that the effect of CCS on subgroups with more than 70% women was statistically less effective compared with placebo (Mean Difference, 1.73 [95% CI, 0.37-3.09]).

CONCLUSION

Evidence suggested that intra-articular pharmacological injections of CCS, HA, and PRP had no effect on improving temporomandibular joint pain and functional outcomes compared with placebo injection.

Second messengers mediating high-molecular-weight hyaluronan-induced antihyperalgesia in rats with chemotherapy-induced peripheral neuropathy

ABSTRACT

High-molecular-weight hyaluronan (HMWH) is an agonist at cluster of differentiation (CD)44, the cognate hyaluronan receptor, on nociceptors, where it acts to induce antihyperalgesia in preclinical models of inflammatory and neuropathic pain. In the present experiments, we studied the CD44 second messengers that mediate HMWH-induced attenuation of pain associated with oxaliplatin and paclitaxel chemotherapy-induced peripheral neuropathy (CIPN). While HMWH attenuated CIPN only in male rats, after ovariectomy or intrathecal administration of an oligodeoxynucleotide (ODN) antisense to G protein-coupled estrogen receptor (GPR30) mRNA, female rats were also sensitive to HMWH. Intrathecal administration of an ODN antisense to CD44 mRNA markedly attenuated HMWH-induced antihyperalgesia in male rats with CIPN induced by oxaliplatin or paclitaxel. Intradermal administration of inhibitors of CD44 second messengers, RhoA (member of the Rho family of GTPases), phospholipase C, and phosphatidylinositol (PI) 3-kinase gamma (PI3Kγ), attenuated HMWH-induced antihyperalgesia as does intrathecal administration of an ODN antisense to PI3Kγ. Our results demonstrated that HMWH induced antihyperalgesia in CIPN, mediated by its action at CD44 and downstream signaling by RhoA, phospholipase C, and PI3Kγ.

Predictors for patient satisfaction of a single intra-articular injection of crosslinked hyaluronic acid combined with mannitol (HANOX-M-XL) in patients with temporomandibular joint osteoarthritis. Results of a prospective open-label pilot study (HAPPYMINI-ARTEMIS trial)

Background

Chronic pain and functional impairment interfere with the quality of life of subjects suffering from temporomandibular joint (TMJ) disorders. Intra-articular (IA) hyaluronic acid (HA) injections have been shown to alleviate pain and improve mandibular mobility in patients with TMJ osteoarthritis (OA).

Objectives

The primary aim of the study was to identify the prognostic factors of patient satisfaction for a single IA injection of a mannitol-modified crosslinked HA (HANOX-M-XL) in patients with TMJ-OA. The second goal was to obtain clinical data on effectiveness, safety and mandibular mobility throughout a six-month follow-up period.

Patients and methods

This was an observational single-arm prospective trial with a six-month follow-up. Inclusion criteria: patients with TMJ-OA which is not relieved by analgesics and/or non-steroidal-anti-inflammatory drugs and/or orthotics, with radiological evidence of TMJ-OA. All patients received a single IA injection of 1 ml HANOX-M-XL in the target TMJ. The primary endpoint was patient satisfaction on day 180. The main secondary outcome measures were pain variation on a 11-point numeric scale (0–11) between the date of injection and month six, the variation over time of the Maximum Inter-Incisal Opening Distance (MIIOD) and the patient’s assessment of effectiveness. Predictive factors of success or failure were also studied. All adverse events were recorded.

Results

36 subjects (mean age 55.3 years, mean disease duration 98 months), covering a total of 52 injected TMJs, were included. Between baseline and endpoint, the average pain while chewing decreased dramatically from 6.9 ± 1.2 to 2.9 ± 1.3 (p < 0.0001) and the MIIOD increased from 29 ± 7 to 35 ± 5 mm (p < 0.01). On day 180, all patients were satisfied with the treatment, with 34 patients (94%) rating it as highly effective or effective. Tolerability was good in all but one patient. In the multivariate analysis, patient satisfaction on day 180 was highly correlated with the pain while chewing score, pain on palpation score and the decrease of pain over time (all p < 0.0001) but not with MIIOD, gender, age, bruxism, articular noise and symptom duration. Previous viscosupplementation was also related to higher satisfaction (p = 0.01).

Conclusion

Despite a long history of pain, most of the patients with symptomatic TMJ-OA benefited from a single injection of HANOX-M-XL, as shown by the sustained (up to 6 months) decrease in pain and improvement in mandibular mobility, with no safety concerns.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05352-3.

An updated view on Temporomandibular Joint degeneration: insights from the cell subsets of mandibular condylar cartilage

The high prevalence of temporomandibular joint osteoarthritis (TMJOA), which causes joint dysfunction, indicates the need for more effective methods for treatment and repair. Mandibular condylar cartilage (MCC), a typical fibrocartilage that experiences degenerative changes during the development of TMJOA, has become a research focus and therapeutic target in recent years. MCC is composed of four zones of cells at various stages of differentiation. The cell subsets in MCC exhibit different physiological and pathological characteristics during development and in TMJOA. Most studies of TMJOA are mainly concerned with gene regulation of pathological changes. The corresponding treatment targets with specific cell subsets in MCC may provide more accurate and reliable results for cartilage repair and TMJOA treatment. In this review, we summarized the current research progress on the cell subsets of MCC from the perspective of MCC development and degeneration. We hope to provide a reference for further exploration of the pathological process of TMJOA and improvement of TMJOA treatment.

PI3Kγ/AKT Signaling in High Molecular Weight Hyaluronan (HMWH)-Induced Anti-Hyperalgesia and Reversal of Nociceptor Sensitization

High molecular weight hyaluronan (HMWH), a well-established treatment for osteoarthritis pain, is anti-hyperalgesic in preclinical models of inflammatory and neuropathic pain. HMWH-induced anti-hyperalgesia is mediated by its action at cluster of differentiation 44 (CD44), the cognate hyaluronan receptor, which can signal via phosphoinositide 3-kinase (PI3K), a large family of kinases involved in diverse cell functions. We demonstrate that intrathecal administration of an oligodeoxynucleotide (ODN) antisense to mRNA for PI3Kγ (a Class I PI3K isoform) expressed in dorsal root ganglia (DRGs), and intradermal administration of a PI3Kγ-selective inhibitor (AS605240), markedly attenuates HMWH-induced anti-prostaglandin E₂ (PGE₂) hyperalgesia, in male and female rats. Intradermal administration of inhibitors of mammalian target of rapamycin (mTOR; rapamycin) and protein kinase B (AKT; AKT Inhibitor IV), signaling molecules downstream of PI3Kγ, also attenuates HMWH-induced anti-hyperalgesia. In vitro patch-clamp electrophysiology experiments on cultured nociceptors from male rats demonstrate that some HMWH-induced changes in generation of action potentials (APs) in nociceptors sensitized by PGE₂ are PI3Kγ dependent (reduction in AP firing rate, increase in latency to first AP and increase in slope of current ramp required to induce AP) and some are PI3Kγ independent [reduction in recovery rate of AP afterhyperpolarization (AHP)]. Our demonstration of a role of PI3Kγ in HMWH-induced anti-hyperalgesia and reversal of nociceptor sensitization opens a novel line of research into molecular targets for the treatment of diverse pain syndromes.SIGNIFICANCE STATEMENT We have previously demonstrated that high molecular weight hyaluronan (HMWH) attenuates inflammatory hyperalgesia, an effect mediated by its action at cluster of differentiation 44 (CD44), the cognate hyaluronan receptor, and activation of its downstream signaling pathway, in nociceptors. In the present study, we demonstrate that phosphoinositide 3-kinase (PI3K)γ and downstream signaling pathway, protein kinase B (AKT) and mammalian target of rapamycin (mTOR), are crucial for HMWH to induce anti-hyperalgesia.

Sexually Dimorphic Role of Toll-like Receptor 4 (TLR4) in High Molecular Weight Hyaluronan (HMWH)-induced Anti-hyperalgesia

High molecular weight hyaluronan (HMWH), a prominent component of the extracellular matrix binds to and signals via multiple receptors, including cluster of differentiation 44 (CD44) and toll-like receptor 4 (TLR4). We tested the hypothesis that, in the setting of inflammation, HMWH acts at TLR4 to attenuate hyperalgesia. We found that the attenuation of prostaglandin E2 (PGE2)-induced hyperalgesia by HMWH was attenuated by a TLR4 antagonist (NBP2-26245), but only in male and ovariectomized female rats. In this study we sought to evaluated the role of the TLR4 signaling pathway in anti-hyperalgesia induced by HMWH in male rats. Decreasing expression of TLR4 in nociceptors, by intrathecal administration of an oligodeoxynucleotide (ODN) antisense to TLR4 mRNA, also attenuated HMWH-induced anti-hyperalgesia, in male and ovariectomized female rats. Estrogen replacement in ovariectomized females reconstituted the gonad-intact phenotype. The administration of an inhibitor of myeloid differentiation factor 88 (MyD88), a TLR4 second messenger, attenuated HMWH-induced anti-hyperalgesia, while an inhibitor of the MyD88-independent TLR4 signaling pathway did not. Since it has previously been shown that HMWH-induced anti-hyperalgesia is also mediated, in part by CD44 we evaluated the effect of the combination of ODN antisense to TLR4 and CD44 mRNA. This treatment completely reversed HMWH-induced anti-hyperalgesia in male rats. Our results demonstrate a sex hormone-dependent, sexually dimorphic involvement of TLR4 in HMWH-induced anti-hyperalgesia, that is MyD88 dependent. PERSPECTIVE: The role of TLR4 in anti-hyperalgesia induced by HMWH is a sexually dimorphic, TLR4 dependent inhibition of inflammatory hyperalgesia that provides a novel molecular target for the treatment of inflammatory pain.

Mechanisms Mediating High-Molecular-Weight Hyaluronan-Induced Antihyperalgesia

We evaluated the mechanism by which high-molecular-weight hyaluronan (HMWH) attenuates nociceptor sensitization, in the setting of inflammation. HMWH attenuated mechanical hyperalgesia induced by the inflammatory mediator prostaglandin E2 (PGE₂) in male and female rats. Intrathecal administration of an oligodeoxynucleotide antisense (AS-ODN) to mRNA for cluster of differentiation 44 (CD44), the cognate hyaluronan receptor, and intradermal administration of A5G27, a CD44 receptor antagonist, both attenuated antihyperalgesia induced by HMWH. In male rats, HMWH also signals via Toll-like receptor 4 (TLR4), and AS-ODN for TLR4 mRNA administered intrathecally, attenuated HMWH-induced antihyperalgesia. Since HMWH signaling is dependent on CD44 clustering in lipid rafts, we pretreated animals with methyl-β-cyclodextrin (MβCD), which disrupts lipid rafts. MβCD markedly attenuated HMWH-induced antihyperalgesia. Inhibitors for components of intracellular signaling pathways activated by CD44, including phospholipase C and phosphoinositide 3-kinase (PI3K), also attenuated HMWH-induced antihyperalgesia. Furthermore, in vitro application of HMWH attenuated PGE₂-induced sensitization of tetrodotoxin-resistant sodium current, in small-diameter dorsal root ganglion neurons, an effect that was attenuated by a PI3K inhibitor. Our results indicate a central role of CD44 signaling in HMWH-induced antihyperalgesia and suggest novel therapeutic targets, downstream of CD44, for the treatment of pain generated by nociceptor sensitization.SIGNIFICANCE STATEMENT High-molecular-weight-hyaluronan (HMWH) is used to treat osteoarthritis and other pain syndromes. In this study we demonstrate that attenuation of inflammatory hyperalgesia by HMWH is mediated by its action at cluster of differentiation 44 (CD44) and activation of its downstream signaling pathways, including RhoGTPases (RhoA and Rac1), phospholipases (phospholipases Cε and Cγ1), and phosphoinositide 3-kinase, in nociceptors. These findings contribute to our understanding of the antihyperalgesic effect of HMWH and support the hypothesis that CD44 and its downstream signaling pathways represent novel therapeutic targets for the treatment of inflammatory pain.

Platelet Concentrate Treatments for Temporomandibular Disorders: A Systematic Review and Meta-analysis

OBJECTIVES

This systematic review compared platelet concentrates (PCs) versus hyaluronic acid (HA) or saline/Ringer's solution injections as treatments of temporomandibular osteoarthritis and disc displacement in terms of pain and maximum mouth opening (MMO).

METHODS

PubMed, Cochrane, and Scopus were searched up to March 6, 2020. Inclusion criteria were randomized clinical trials (RCTs). Exclusion criteria were case series, observational studies, animal studies, and reviews. The Effective Public Health Practice Project (EPHPP) quality assessment tool was used to assess the risk of bias in the included studies. The weighted mean difference was used to compare the results.

RESULTS

Nine RCTs were included with a total of 407 patients. The numbers of joints treated were 262, 112, and 112 in the PC, HA, and saline groups, respectively. The quality of studies was rated as strong in 4 studies, moderate in 4 studies, and weak in 1 study. The meta-analysis revealed that PCs decreased pain visual analogue scale (VAS) scores compared to HA by an average of -1.11 (CI, -1.62 to -0.60; P < 0.0001) and -0.57 (CI, -1.55 to 0.41; P = 0.26) at 3 and 12 mo follow-up respectively. Also, the average decrease in pain scores with PC compared to saline was -1.33 (CI, -2.61 to -0.06; P = 0.04), -2.07 (CI, -3.46 to -0.69; P = 0.003), and -2.71 (CI, -4.69 to -0.72; P = 0.008) at 3, 6, and 12 mo, respectively. Regarding MMO measurements, PC was comparable to HA, but it was significantly better than saline after 3 and 6 mo [2.9 mm (CI,1.47 to 4.3; P < 0.0001), and 1.69 mm (CI, 0.13 to 3.25; P = 0.03) respectively].

CONCLUSION

PC reduces pain VAS scores compared to HA during the first 3 m after treatment, and when compared to saline, it reduces pain and increases MMO for longer durations. However, due to differences between groups regarding PC preparation protocols and study heterogeneity, further standardized RCTs are required.

KNOWLEDGE TRANSFER STATEMENT

This study provides researchers and clinicians with quantitative and qualitative analyses of the current evidence regarding the clinical outcomes of platelet concentrate injections in the treatment of temporomandibular joint osteoarthritis and disc displacement in terms of pain control and maximum mouth opening.

Prospective study to evaluate the influence of joint washing and the use of hyaluronic acid on 111 arthrocentesis

BACKGROUND

Temporomandibular dysfunction is a generic term that covers a large number of clinical problems affecting not only temporomandibular joint but also the masticatory musculature and related structures. Arthrocentesis is used in patients with joint pathology in which conservative treatment has failed.

METHODS

A prospective, observational, analytical cohort study has been carried out to evaluate the results of 111 arthrocentesis. We have performed an inferential statistics study between the variables: improvement of pain and improvement in the oral opening with the variables and access joint, washing joint, hyaluronic acid infiltration, and type of joint pathology.

RESULTS

Joint washing and intra-articular hyaluronic acid injection significantly improved the pain at 1-week, 1-month, and 3-month postarthrocentesis, although this improvement was limited in time, at 6 months, joint washing and hyaluronic acid infiltration are no longer significant. Only the joint access (p = 0.014) and the type of joint pathology (p = 0.028) are significant.

CONCLUSIONS

The effectiveness of joint access in the arthrocentesis at 6 months is high, although less than at 1-month and 3-month postarthrocentesis. The type of joint pathology is another important factor. Patients with degenerative pathology worsen the most after 6-month postarthrocentesis. Arthrocentesis could avoid the evolution of acute pathology.

Five Years' Outcomes of Trabeculectomy with Cross-linked Sodium Hyaluronate Gel Implantation for Chinese Glaucoma Patients

Background:

Trabeculectomy is the most efficient surgical treatment. Prevention failure of bleb cicatrix would lead to unsatisfactory postoperative intraocular pressure (IOP) controlling and unsatisfactory success rate. The aim of this study was to evaluate the 5-year outcomes of trabeculectomy with a cross-linked sodium hyaluronate gel implantation for Chinese glaucoma patients.

Methods:

This is a prospective, case-controlled study. Patients who were to be applied first-time trabeculectomy in the Department of Ophthalmology of Peking University Third Hospital between 2010 and 2012 were included in the study. Totally, 60 eyes were randomly assigned to the trabeculectomy group (TA group) or the trabeculectomy with cross-linked sodium hyaluronate gel implantation group (TH group). Follow-up was finished at 1 week, 1 month, 3 months, 1 year, 3 years, and 5 years after the operation. The statistical index of demographic data, IOP, bleb shape, and any complications or medications or surgical procedures were recorded and assessed by SPSS 19.0 software through independent t-test, one-way analysis of variance (ANOVA) and Pearson's Chi-square test, respectively.

Results:

The baseline IOP was comparable between the two groups (t= −1.00, P= 0.32) while the postoperative IOP was significantly lower in the TH group at 1, 3 and 5 years' time points (P = 0.00, P= 0.01 and P = 0.01, respectively). According to the Indiana Bleb Appearance Grading Scale, the height and extent of bleb were better in the TH group at all follow-up time points (P < 0.05), however, the comparison of bleb vascularity showed no statistical difference (P > 0.05). TA group had a higher percentage of complications (13% vs. 3%) compared to TH group; however, there was no statistical difference in the comparison of each statistical item (P > 0.05, respectively). The complete success at 5 years was higher in the TH group than that in the TA group (78% vs. 54%, P = 0.03).

Conclusion:

Our results suggested that implantation of cross-linked sodium hyaluronate gel with trabeculectomy was more efficient and would improve the prognosis of glaucoma patients.

Non-invasive different modalities of treatment for temporomandibular disorders: review of literature

Temporomandibular disorders (TMDs) are diseases that affect the temporomandibular joint and supporting structures. The goal of treatment for TMDs is elimination or reduction of pain and return to normal temporomandibular joint function. Initial treatment for TMDs is non-invasive and conservative, not surgical. Oral and maxillofacial surgeons should fully understand and actively care about non-invasive treatments for TMDs. The purpose of this study is to review the validity and outcomes of non-invasive and surgical treatment modalities for TMDs.

CD44 Signaling Mediates High Molecular Weight Hyaluronan-Induced Antihyperalgesia

We studied, in male Sprague Dawley rats, the role of the cognate hyaluronan receptor, CD44 signaling in the antihyperalgesia induced by high molecular weight hyaluronan (HMWH). Low molecular weight hyaluronan (LMWH) acts at both peptidergic and nonpeptidergic nociceptors to induce mechanical hyperalgesia that is prevented by intrathecal oligodeoxynucleotide antisense to CD44 mRNA, which also prevents hyperalgesia induced by a CD44 receptor agonist, A6. Ongoing LMWH and A6 hyperalgesia are reversed by HMWH. HMWH also reverses the hyperalgesia induced by diverse pronociceptive mediators, prostaglandin E₂, epinephrine, TNFα, and interleukin-6, and the neuropathic pain induced by the cancer chemotherapy paclitaxel. Although CD44 antisense has no effect on the hyperalgesia induced by inflammatory mediators or paclitaxel, it eliminates the antihyperalgesic effect of HMWH. HMWH also reverses the hyperalgesia induced by activation of intracellular second messengers, PKA and PKC_ε, indicating that HMWH-induced antihyperalgesia, although dependent on CD44, is mediated by an intracellular signaling pathway rather than as a competitive receptor antagonist. Sensitization of cultured small-diameter DRG neurons by prostaglandin E₂ is also prevented and reversed by HMWH. These results demonstrate the central role of CD44 signaling in HMWH-induced antihyperalgesia, and establish it as a therapeutic target against inflammatory and neuropathic pain.SIGNIFICANCE STATEMENT We demonstrate that hyaluronan (HA) with different molecular weights produces opposing nociceptive effects. While low molecular weight HA increases sensitivity to mechanical stimulation, high molecular weight HA reduces sensitization, attenuating inflammatory and neuropathic hyperalgesia. Both pronociceptive and antinociceptive effects of HA are mediated by activation of signaling pathways downstream CD44, the cognate HA receptor, in nociceptors. These results contribute to our understanding of the role of the extracellular matrix in pain, and indicate CD44 as a potential therapeutic target to alleviate inflammatory and neuropathic pain.

Is Hyaluronic Acid or Corticosteroid Superior to Lactated Ringer Solution in the Short Term for Improving Function and Quality of Life After Arthrocentesis? Part 2

PURPOSE

Although arthrocentesis has been used for the management of patients with temporomandibular joint pain, the benefit of hyaluronic acid (HA) or corticosteroid (CS) remains uncertain. The purpose of this study was to assess the efficacy of HA, CS, and lactated Ringer solution (LR; placebo) after arthrocentesis for changes in quality of life (QoL), jaw function (Jaw Function Limitation Scale [JFLS] score), and maximum incisal opening (MIO).

MATERIALS AND METHODS

This was a prospective multicenter double-blinded randomized clinical trial. Consecutive patients presenting to the oral and maxillofacial departments at Emory University, the University of Pennsylvania, the University of California-Los Angeles, the University of Cincinnati, and the Oregon Health Sciences University were enrolled in the study. Patients were randomized to HA, CS, or LR. All patients underwent arthrocentesis and then instillation of HA, CS, or LR. All patients were evaluated clinically at 1 and 3 months. The outcome variables were QoL, JFLS score, and MIO. Univariate, bivariate, and multivariate statistics were computed, with a P value less than .05 considered significant.

RESULTS

One hundred two patients were enrolled in the study. Four were lost to follow-up, leaving 98 patients for analysis of data at 1 month. An additional 51 were lost to follow-up at 3 months, leaving 51 patients for data analysis at this time point. There was no difference among groups for QoL Mental Health Composite score at 1 month (P = .70) or 3 months (P = .69). There was no difference among groups for JFLS score at 1 month (P = .71) or 3 months (P = .98). There was no difference among groups for MIO at 1 month (P = .47) or 3 months (P = .31). All groups showed within-group improvements in JFLS score and MIO at 1 and 3 months.

CONCLUSION

Arthrocentesis alone is as efficacious as arthrocentesis with HA or CS in improving jaw function and MIO at 1 and 3 months. QoL is not improved with arthrocentesis alone or in combination with CS or HA.

Extracellular matrix hyaluronan signals via its CD44 receptor in the increased responsiveness to mechanical stimulation

We propose that the extracellular matrix (ECM) signals CD44, a hyaluronan receptor, to increase the responsiveness to mechanical stimulation in the rat hind paw. We report that intradermal injection of hyaluronidase induces mechanical hyperalgesia, that is inhibited by co-administration of a CD44 receptor antagonist, A5G27. The intradermal injection of low (LMWH) but not high (HMWH) molecular weight hyaluronan also induces mechanical hyperalgesia, an effect that was attenuated by pretreatment with HMWH or A5G27. Pretreatment with HMWH also attenuated the hyperalgesia induced by hyaluronidase. Similarly, intradermal injection of A6, a CD44 receptor agonist, produced hyperalgesia that was inhibited by HMWH and A5G27. Inhibitors of protein kinase A (PKA) and Src, but not protein kinase C (PKC), significantly attenuated the hyperalgesia induced by both A6 and LMWH. Finally, to determine if CD44 receptor signaling is involved in a preclinical model of inflammatory pain, we evaluated the effect of A5G27 and HMWH on the mechanical hyperalgesia associated with the inflammation induced by carrageenan. Both A5G27 and HMWH attenuated carrageenan-induced mechanical hyperalgesia. Thus, while LMWH acts at its cognate receptor, CD44, to induce mechanical hyperalgesia, HMWH acts at the same receptor as an antagonist. That the local administration of HMWH or A5G27 inhibits carrageenan-induced hyperalgesia supports the suggestion that carrageenan produces changes in the ECM that contributes to inflammatory pain. These studies define a clinically relevant role for signaling by the hyaluronan receptor, CD44, in increased responsiveness to mechanical stimulation.

Current understanding of pathogenesis and treatment of TMJ osteoarthritis

Osteoarthritis is a common disease that can cause severe pain and dysfunction in any joint, including the temporomandibular joint (TMJ). TMJ osteoarthritis (TMJOA) is an important subtype in the classification of temporomandibular disorders. TMJOA pathology is characterized by progressive cartilage degradation, subchondral bone remodeling, and chronic inflammation in the synovial tissue. However, the exact pathogenesis and process of TMJOA remain to be understood. An increasing number of studies have recently focused on inflammation and remodeling of subchondral bone during the early stage of TMJOA, which may elucidate the possible mechanism of initiation and progression of TMJOA. The treatment strategy for TMJOA aims at relieving pain, preventing the progression of cartilage and subchondral bone destruction, and restoring joint function. Conservative therapy with nonsteroidal anti-inflammatory drugs, splint, and physical therapy, such as low-energy laser and arthrocentesis, are the most common treatments for TMJOA. These therapies are effective in most cases in relieving the signs and symptoms, but their long-term therapeutic effect on the pathologic articular structure is unsatisfactory. A treatment that can reverse the damage of TMJOA remains unavailable to date. Treatments that prevent the progression of cartilage degradation and subchondral bone damage should be explored, and regeneration for the TMJ may provide the ideal long-term solution. This review summarizes the current understanding of mechanisms underlying the pathogenesis and treatment of TMJOA.

Osteoarthritic changes after superior and inferior joint space injection of hyaluronic acid for the treatment of temporomandibular joint osteoarthritis with anterior disc displacement without reduction: a cone-beam computed tomographic evaluation

PURPOSE

This study compared the effect of superior and inferior joint space injections of hyaluronic acid (HA) and evaluated osteoarthritic changes in patients diagnosed with temporomandibular joint (TMJ) anterior disc displacement without reduction (ADDw/oR) in association with osteoarthritis (OA) by cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

One hundred forty-one patients with research diagnostic criteria for ADDw/oR in association with TMJ OA were randomly assigned to 1 of 2 study groups that received superior or inferior joint space injection of HA. CBCT and clinical examination were performed before treatment and at 3 and 9 months after treatment.

RESULTS

One hundred twenty-six patients returned for the 3-month evaluations, and 74 returned for the 9-month evaluations. Condylar remodeling and TMJ function showed improvement in most patients after treatment. At 3 months, remodeling scores in the superior and inferior groups were 2.14 ± 3.16 and 4.08 ± 3.82, respectively, and scores were 4.80 ± 3.36 and 7.47 ± 3.90 at 9 months. There were significant differences between the superior and inferior groups at 3 and 9 months after treatment (3-month, P = .002; 9-month, P = .002). The Helkimo index of the inferior group was significantly lower than that of superior group at 3 and 9 months (3-month, P = .008; 9-month, P = .028). There were no significant differences in maximal mouth opening between the 2 groups at 3 and 9 months (3-month, P = .82; 9-month, P = .20).

CONCLUSION

Superior and inferior joint space injections of HA are effective methods for the treatment of ADDw/oR in association with TMJ OA. The injection of HA within the inferior joint space appears to result in better condylar reparative remodeling and improvement in jaw function.