Gene Expression Profiling of IL-17A-Treated Synovial Fibroblasts from the Human Temporomandibular Joint

Identification of potential immune-related genes and infiltrations in temporomandibular joint osteoarthritis

Objective

The aim of this study was to investigate the potential inflammatory cytokines and chemokines markers for temporomandibular joint osteoarthritis (TMJOA) diagnosis using a bioinformatics analysis.

Methods

The differentially expressed genes of mRNA (DEGs) and transcripts of lncRNA (DETs) were identified between TMJOA samples and normal controls curated from GSE205389 by the "DESeq. 2" R package. KEGG and GO were conducted using the R package "ggplot2" and "clusterProfiler". A PPI network was constructed to identify hub genes by using the STRING and Cytoscape. The co-expression network was constructed between mRNA and lncRNA to check the potential regulation and function of lncRNA on protein-coding genes. Finally, the immune cell infiltration analysis was conducted with CIBERSORTx and confirmed with xCells.

Results

The authors identified 171 DEGs and DETs, of which the DEGs were closely related to immune response, T-cell activation, cytokine-cytokine-receptor interaction, and the muscle system process. PPI network of the DEGs screened the top 10 hub genes, including IL6, IL1B, IL10, CCL2, CCL5, CXCL1, CXCL10, ICAM1, CSF1 and MMP1. Additionally, the immune cell infiltration analysis showed that CD8+ T cells, M1 macrophage and B cells infiltration were increased in TMJOA samples. Finally, the authors demonstrated that the co-expression between mRNA and lncRNA was mainly enriched in inflammatory and muscle-related pathways.

Conclusions

The authors found that immune and muscle system-related pathways as well as the immune infiltration played a significant role in the TMJOA development. Additionally, inflammatory cytokines and chemokines could be crucial markers for early-stage TMJOA diagnosis and personalized treatment strategies.

IL-17 in skin infections and homeostasis

Interleukin (IL) 17 is a proinflammatory cytokine belonging to a structurally related group of cytokines known as the IL-17 family. It has been profoundly studied for its contribution to the pathology of autoimmune diseases. However, it also plays an important role in homeostasis and the defense against extracellular bacteria and fungi. IL-17 is important for epithelial barriers, including the skin, where some of its cellular targets reside. Most of the research work on IL-17 has focused on its effects in the skin within the context of autoimmune diseases or sterile inflammation, despite also having impact on other skin conditions. In recent years, studies on the role of IL-17 in the defense against skin pathogens and in the maintenance of skin homeostasis mediated by the microbiota have grown in importance. Here we review and discuss the cumulative evidence regarding the main contribution of IL-17 in the maintenance of skin integrity as well as its protective or pathogenic effects during some skin infections.

Mechanisms Underlying Sex Differences in Temporomandibular Disorders and Their Comorbidity with Migraine

Sexual dimorphism in temporomandibular disorders (TMDs) and their comorbidity with migraine are important phenomena observed in clinics. TMDs are the most prevalent orofacial pain conditions with jaw joint and masseter muscle dysfunction. Migraine is the predominant headache commonly associated with TMDs. Women much more often suffer from this orofacial pain than men. However, currently, there is no gender-specific therapy for such pain conditions. Understanding the pathophysiological mechanisms behind sex differences in TMDs as well as their comorbidity with migraines is essential for developing novel approaches for gender-specific treatment of TMDs and related orofacial pain comorbidity. In this review, we summarize recent research progress regarding sex differences in TMDs, focusing on the underlying mechanisms including craniofacial anatomy, hormonal regulation, and roles of opioids, transient receptor potential channels, and endocannabinoid systems. We also discuss the mechanisms of comorbid TMDs and migraine. The information covered in this review will provide mechanistic insights into sex differences in TMDs and their comorbidity with migraine, which could aid in developing effective treatment strategies for the overlapping orofacial pain condition.

Psoriatic Arthritis Involving TMJ: A Review on Pathogenesis and Consideration on Eventual Gender Differences

Psoriatic arthritis is defined as chronic inflammatory arthritis associated with psoriasis. The current data regarding gender differences in clinical manifestation and therapeutic outcomes of psoriatic arthritis are limited. Generally, men show a peripheral disease manifestation, while women have an axial distribution of the lesions. If we look at temporomandibular joint (TMJ) involvement, epidemiological data on the involvement of the TMJ are hard to find. Few studies on therapeutic management and the related impact on the quality of life are reported in the literature. Given the morpho-functional peculiarities of the TMJ and the different pain burdens between male and female genders, when manifestation of psoriatic arthritis occurs, clinicians should face it using a multidisciplinary approach for a correct diagnosis and successful treatment. This review aims to examine the diagnostic signs of psoriatic arthritis in the TMJ, the eventual variations of this disease in male and female patients, and the therapeutical strategies. The coordination of different specialties is fundamental to the remission of clinical symptoms and lesion regression.

A single-cell atlas of IL-23 inhibition in cutaneous psoriasis distinguishes clinical response

Psoriasis vulgaris and other chronic inflammatory diseases improve markedly with therapeutic blockade of interleukin-23 (IL-23) signaling, but the genetic mechanisms underlying clinical responses remain poorly understood. Using single-cell transcriptomics, we profiled immune cells isolated from lesional psoriatic skin before and during IL-23 blockade. In clinically responsive patients, a psoriatic transcriptional signature in skin-resident memory T cells was strongly attenuated. In contrast, poorly responsive patients were distinguished by persistent activation of IL-17-producing T (T17) cells, a mechanism distinct from alternative cytokine signaling or resistance isolated to epidermal keratinocytes. Even in IL-23 blockade-responsive patients, we detected a recurring set of recalcitrant, disease-specific transcriptional abnormalities. This irreversible immunological state may necessitate ongoing IL-23 inhibition. Spatial transcriptomic analyses also suggested that successful IL-23 blockade requires dampening of >90% of IL-17-induced response in lymphocyte-adjacent keratinocytes, an unexpectedly high threshold. Collectively, our data establish a patient-level paradigm for dissecting responses to immunomodulatory treatments.

Level of Disability after Total Hip Replacement in Patients with Some COMT Gene Polymorphism

BACKGROUND

The COMT gene encodes the enzyme catechol-O-methyltransferase, which is a key modulator of dopaminergic and adrenergic neurotransmission. Hip osteoarthritis is accompanied by reduced mobility and some level of disability. In our study, we analyzed the association between some COMT gene polymorphisms and reduced mobility in patients after total hip replacement (THR).

METHODS

The operative procedures were performed on 195 patients with symptomatic and radiologically advanced hip osteoarthritis. In the postoperative follow-up, we assessed hip function with the Harris Hip Score (HHS) and the degree of disability with the Oswestry Disability Index (ODI). These procedures were repeated three times at defined intervals (one week, six weeks, and six months) after the total hip replacement. Genomic DNA was extracted from peripheral blood. SNPs in the COMT genes rs4680:A>G, rs6269:A>G, rs4633:C>T, and rs4818:C>G were genotyped.

RESULTS

Our findings suggest an association between COMT gene variability and the level of disability measured by the Oswestry Disability Index (ODI) in patients after total hip replacement (THR).

CONCLUSIONS

A higher number of COMT G alleles (rs4818) is an independent factor in a significant reduction in disability degree at both one week and six months after total hip replacement (THR), regardless of age or gender.

Potential pathological and molecular mechanisms of temporomandibular joint osteoarthritis

Temporomandibular joint osteoarthritis (TMJ OA) is a progressive degenerative disease of the temporomandibular joint (TMJ). The unclear etiology and mechanisms of TMJ OA bring great difficulties to early diagnosis and effective treatment, causing enormous burdens to patients' life and social economics. In this narrative review, we summarized the main pathological changes of TMJ OA, including inflammatory responses, degeneration of extracellular matrix (ECM), abnormal cell biological behaviors (apoptosis, autophagy, and differentiation) in TMJ tissue, and aberrant angiogenesis. All pathological features are closely linked to each other, forming a vicious cycle in the process of TMJ OA, which results in prolonged disease duration and makes it difficult to cure. Various molecules and signaling pathways are involved in TMJ OA pathogenesis, including nuclear factor kappa-B (NF-κB), mitogen-activated protein kinases (MAPKs), extracellular regulated protein kinases (ERKs) and transforming growth factor (TGF)-β signaling pathways et al. One molecule or pathway can contribute to several pathological changes, and the crosstalk between different molecules and pathways can further lead to a complicated condition TMJ OA. TMJ OA has miscellaneous etiology, complex clinical status, depressed treatment results, and poor prognosis. Therefore, novel in-vivo and in-vitro models, novel medicine, materials, and approaches for therapeutic procedures might be helpful for further investigation of TMJ OA. Furthermore, the role of genetic factors in TMJ OA needs to be elucidated to establish more reasonable and effective clinical strategies for diagnosing and treating TMJ OA.

The protective capability of Hedyotis diffusa Willd on lupus nephritis by attenuating the IL-17 expression in MRL/lpr mice

Lupus nephritis (LN), the most severe organ manifestation of systemic lupus erythematosus (SLE), is generally treated with glucocorticoids (GC) in clinical practice, leading to drug resistance and adverse effects in the long term. Fortunately, the combination of GC and traditional Chinese medical prescriptions can attenuate the adverse effects and improve therapeutic efficiency. Hedyotis diffusa Willd (HDW) is one of the most commonly used herbal compounds for LN treatment, which exhibits “heat-clearing” and “detoxification” effects. However, the underlying pharmacological mechanism remains unclear. The present study identified the chemical compounds in HDW extract with UPLC-Q-TOF-MS/MS. A total of 49 components were identified in the HDW extract, and the IL-17 signaling pathway was highly enriched by network pharmacological analysis. MRL/lpr model mice, reflecting the spontaneous development of LN, were used to evaluate the protective activity and investigate the underlying mechanism of the combination treatment. The white blood cell content (WBC), including lymphocytes and neutrophils, cytokines (IL-6, MCP-1, TNF-a), and various autoantibodies (ANA, ab-dsDNA, ab-snRNP/sm) in the blood of MRL/lpr mice were significantly improved by the intragastric administration of HDW. Additionally, the expression of STAT3, IL-17, Ly6G, and MPO in the kidney and neutrophil NETosis were ameliorated with HDW treatment. The pathological and morphological analysis suggested that HDW application could reduce urinary protein levels and inflammatory cell infiltration and inhibit glomerular interstitial cell proliferation. Hence, HDW might ameliorate lupus nephritis by inhibiting IL-6 secretion and STAT3-induced IL-17 expression. The active compounds in HDW were predictively selected with computational methods. The docking affinity of asiatic acid, neoandrographolide to IL-6, glycyrrhetinic acid, oleanolic acid, ursolic acid, and wilforlide A to STAT3 are extremely high. In conclusion, the IL-6 and STAT3/IL-17signaling pathways could be critical regulative targets of HDW on LN.

Network Pharmacology Analysis and Experimental Validation to Investigate the Mechanism of Total Flavonoids of Rhizoma Drynariae in Treating Rheumatoid Arthritis

Objective

The study aimed to explore the mechanism of total flavonoids of Rhizoma Drynariae (TFRD) in the treatment of rheumatoid arthritis (RA) based on network pharmacology and experimental validation.

Methods

The active components of TFRD were identified from TCMSP and TCMID databases. Relevant targets of the active compounds of TFRD and RA-related targets were predicted by public databases online. A component-target (C-T) regulatory network was constructed by Cytoscape. The genes of TFRD regulating RA were imported into STRING database to construct a protein-protein interaction (PPI) network in order to predict the key targets. KEGG enrichment analysis was performed to predict the crucial mechanism of TFRD against RA. The active components of TFRD underwent molecular docking with the key proteins. Collagen-induced arthritis (CIA) model of rats and inflammatory factors-stimulated fibroblast-like synoviocytes were used in vivo and in vitro to validate the efficacy and predicted critical mechanisms of TFRD.

Results

Network Pharmacology analysis revealed that TFRD had 14 active compounds, corresponding to 213 targets, and RA related to 2814 genes. There were 137 intersection genes between TFRD and RA. KEGG indicated that therapeutic effects of TFRD on RA involves T cell receptor signaling pathway, Th17 cell differentiation, IL-17 signaling pathway, TNF signaling pathway, MAPK signaling pathway and PI3K/AKT signaling pathway. In vivo experiments suggested TFRD can alleviate the inflammatory response, joint swelling and synovial abnormality of CIA rats. TFRD contributed to the decrease of Th17 cells and the down-regulated secretion of IL-17A and TNF-α of activated lymphocyte in CIA model. In vitro experiments confirmed TFRD can effectively inhibit the inflammatory response of fibroblast-like synoviocytes and suppress the abnormal activation of MAPK, PI3K/AKT and NFκB signaling pathways.

Conclusion

The treatment of RA with TFRD is closely related to inhibiting Th17 differentiation and inflammatory response of synoviocytes.

Autoimmunity in human CE: Correlative with the fertility status of the CE cyst

Cystic echinococcosis is speculated to exert several immune-evasion strategies involving autoimmune-phenomena. We evaluated the hypothesizes that the prevalence of autoantibodies increases in the sera of CE patients that may evidence the association between the parasite and autoimmune diseases. Sera from 63 subjects at distinct types of CE cyst fertility were investigated for antinuclear antibodies (ANA), and anti-CCP antibodies. Plasma levels and cellular production of IL-17A cytokine were specifically defined as being assumed to prime for autoimmunity. Healthy-controls were age and gender-matched to test sera. ANA expressions inside the surgically removed metacestode and adventitial layer were also assayed. Out of 63 patients, 35 % had fertile highly viable cysts (group-1), 41 % had fertile low viable cysts (group-2) and 24 % had non-fertile cysts (group-3). A four-fold increase in ANA sera-levels was detected in group-1 compared with their controls (p-value 0.001) while anti-CCP levels were of insignificant differences. In group-2 and group-3, no significant differences were detected between ANA and anti-CCP sera-levels in CE patients and their controls. IL-17A sera-levels in group-1 and group- 2 were significantly higher than their healthy-controls while being of insignificant differences in group-3, p-value= 0.300. No association was detected between sera-levels of IL-17A and ANA as well as anti-CCP antibodies. Interestingly, relative IL-17A cellular expression associated positive ANA deposition in the parasite cells and adventitial layer. Collectively, based on the parasite fertility, IL-17A and ANA seemed to be involved in the host immune defenses against CE. There is no association between CE and anti-CCP antibodies.

A Role of IL-17 in Rheumatoid Arthritis Patients Complicated With Atherosclerosis

Rheumatoid arthritis (RA) is mainly caused by joint inflammation. RA significantly increases the probability of cardiovascular disease. Although the progress of RA has been well controlled recently, the mortality of patients with RA complicated with cardiovascular disease is 1.5–3 times higher than that of patients with RA alone. The number of people with atherosclerosis in patients with RA is much higher than that in the general population, and atherosclerotic lesions develop more rapidly in patients with RA, which has become one of the primary factors resulting in the death of patients with RA. The rapid development of atherosclerosis in RA is induced by inflammation-related factors. Recent studies have reported that the expression of IL-17 is significantly upregulated in patients with RA and atherosclerosis. Simultaneously, there is evidence that IL-17 can regulate the proliferation, migration, and apoptosis of vascular endothelial cells and vascular smooth muscle cells through various ways and promote the secretion of several cytokines leading to the occurrence and development of atherosclerosis. Presently, there is no clear prevention or treatment plan for atherosclerosis in patients with RA. Therefore, this paper explores the mechanism of IL-17 in RA complicated with atherosclerosis and shows the reasons for the high incidence of atherosclerosis in patients with RA. It is hoped that the occurrence and development of atherosclerosis in patients with RA can be diagnosed or prevented in time in the early stage of lesions, and the prevention and treatment of cardiovascular complications in patients with RA can be enhanced to reduce mortality.

Osteoimmunology of Oral and Maxillofacial Diseases: Translational Applications Based on Biological Mechanisms

The maxillofacial skeleton is highly dynamic and requires a constant equilibrium between the bone resorption and bone formation. The field of osteoimmunology explores the interactions between bone metabolism and the immune response, providing a context to study the complex cellular and molecular networks involved in oro-maxillofacial osteolytic diseases. In this review, we present a framework for understanding the potential mechanisms underlying the immuno-pathobiology in etiologically-diverse diseases that affect the oral and maxillofacial region and share bone destruction as their common clinical outcome. These otherwise different pathologies share similar inflammatory pathways mediated by central cellular players, such as macrophages, T and B cells, that promote the differentiation and activation of osteoclasts, ineffective or insufficient bone apposition by osteoblasts, and the continuous production of osteoclastogenic signals by immune and local stromal cells. We also present the potential translational applications of this knowledge based on the biological mechanisms involved in the inflammation-induced bone destruction. Such applications can be the development of immune-based therapies that promote bone healing/regeneration, the identification of host-derived inflammatory/collagenolytic biomarkers as diagnostics tools, the assessment of links between oral and systemic diseases; and the characterization of genetic polymorphisms in immune or bone-related genes that will help diagnosis of susceptible individuals.

P2Y11 receptor antagonist NF340 ameliorates inflammation in human fibroblast-like synoviocytes: An implication in rheumatoid arthritis

Rheumatoid arthritis is a common chronic inflammatory joint disease. Fibroblast-like synoviocytes-mediated inflammation is closely associated with the development of rheumatoid arthritis. In this study, we report that P2Y11 receptor activity is required for cytokine-induced inflammation in primary fibroblast-like synoviocytes (FLS). P2Y11R is fairly expressed in primary FLS isolated from healthy subjects and is elevated to around three- to four-fold in rheumatoid arthritis-derived FLS. The expression of P2Y11R is inducible upon IL-1β treatment. Blockage of P2Y11R by its antagonist suppresses IL-1β-induced TNF-α and IL-6 induction and ameliorates oxidative stress as determined by levels of cellular ROS and the oxidative byproduct 4-HNE. Moreover, blockage of P2Y11R by NF340 inhibits IL-1β-induced matrix metalloproteinase protein expression as indicated by the levels of MMP-1, MMP-3, and MMP-13. Mechanistically, blockage of P2Y11R mitigates IL-1β-activated NFκB signaling, which was revealed by reduced IκBα phosphorylation, nuclear p65 accumulation, and NFκB promoter activity. Our study provides evidence of a protective mechanism of P2Y11R antagonist NF340 against cytokine-induced inflammation. Therefore, targeting P2Y11R could have potential therapeutic implication in the treatment of RA.

Systemic effects of IL-17 in inflammatory arthritis

Inflammatory arthritis occurs in many diseases and is characterized by joint inflammation and damage. However, the inflammatory state in arthritis is commonly associated with systemic manifestations, which are generally linked to a poor prognosis. The pro-inflammatory cytokine IL-17 functions within a complex network of cytokines and contributes to the pathogenesis of various inflammatory diseases. Three IL-17 inhibitors have already been approved for the treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis. After a brief description of IL-17 and its local effects on joints, this Review focuses on the systemic effects of IL-17 in inflammatory arthritis. Increased circulating concentrations of bioactive IL-17 mediate changes in blood vessels, liver and cardiac and skeletal muscles. The effects of IL-17 on vascular and cardiac cells might contribute to the increased risk of cardiovascular events that occurs in all patients with inflammatory disorders. In the liver, IL-17 contributes to the high circulating concentrations of acute-phase proteins, such as C-reactive protein, and the appearance of liver lesions. In skeletal muscle, IL-17 contributes to muscle contractibility defects and weakness. Thus, targeting IL-17 might have beneficial effects at both local and systemic levels, and could also be proposed for the treatment of a wider range of inflammatory diseases.

Distinct degenerative phenotype of articular cartilage from knees with meniscus tear compared to knees with osteoarthritis

OBJECTIVE

To compare the transcriptome of articular cartilage from knees with meniscus tears to knees with end-stage osteoarthritis (OA).

DESIGN

Articular cartilage was collected from the non-weight bearing medial intercondylar notch of knees undergoing arthroscopic partial meniscectomy (APM; N = 10, 49.7 ± 10.8 years, 50% females) for isolated medial meniscus tears and knees undergoing total knee arthroplasty (TKA; N = 10, 66.0 ± 7.6 years, 70% females) due to end-stage OA. Ribonucleic acid (RNA) preparation was subjected to SurePrint G3 human 8 × 60K RNA microarrays to probe differentially expressed transcripts followed by computational exploration of underlying biological processes. Real-time polymerase chain reaction amplification was performed on selected transcripts to validate microarray data.

RESULTS

We observed that 81 transcripts were significantly differentially expressed (45 elevated, 36 repressed) between APM and TKA samples (≥ 2 fold) at a false discovery rate of ≤ 0.05. Among these, CFD, CSN1S1, TSPAN11, CSF1R and CD14 were elevated in the TKA group, while CHI3L2, HILPDA, COL3A1, COL27A1 and FGF2 were highly expressed in APM group. A few long intergenic non-coding RNAs (lincRNAs), small nuclear RNAs (snoRNAs) and antisense RNAs were also differentially expressed between the two groups. Transcripts up-regulated in TKA cartilage were enriched for protein localization and activation, chemical stimulus, immune response, and toll-like receptor signaling pathway. Transcripts up-regulated in APM cartilage were enriched for mesenchymal cell apoptosis, epithelial morphogenesis, canonical glycolysis, extracellular matrix organization, cartilage development, and glucose catabolic process.

CONCLUSIONS

This study suggests that APM and TKA cartilage express distinct sets of OA transcripts. The gene profile in cartilage from TKA knees represents an end-stage OA whereas in APM knees it is clearly earlier in the degenerative process.

The many faces of genetic contributions to temporomandibular joint disorder: An updated review

OBJECTIVES

The aim was to review the literature regarding genetic contributions to temporomandibular joint disorder (TMD) after our 2008 publication.

SETTING AND SAMPLE POPULATION

Literature review.

MATERIAL AND METHODS

PubMed and MEDLINE were used to obtain literature in any language regarding genes and TMD, using the keywords "temporomandibular joint disorder" and "temporomandibular joint dysfunction" for studies published from 2009 to 2017.

RESULTS

In our search, 274 studies were found. We excluded 76 studies from animal models, 22 studies that were in vitro and 120 reports that were not cohort or case-control studies. Of the 274 results, 56 articles were selected for this review. Genes that are suggested to contribute to TMD included the ones related to disc and bone alterations as well as pain sensation.

CONCLUSION

Currently, no evidence of associated genetic variants, which can determine the development of TMD in individuals, could be translated to novel clinical management and public health strategies for patients suffering from TMD.