Dysregulation of both miR-140-3p and miR-140-5p in synovial fluid correlate with osteoarthritis severity

Knocking-down long non-coding RNA LINC01094 prohibits chondrocyte apoptosis via regulating microRNA-577/metal-regulatory transcription factor 1 axis

PURPOSE

The abnormal function and survival of chondrocytes result in articular cartilage failure, which may accelerate the onset and development of osteoarthritis (OA). This study is aimed to investigate the role of LINC01094 in chondrocyte apoptosis.

METHODS

The viability and apoptosis of lipopolysaccharide (LPS)-induced chondrocytes were evaluated through CCK-8 assay and flow cytometry analysis, respectively. The expression levels of LINC01094, miR-577 and MTF1 were detected by qRT-PCR. Dual luciferase reporter tests were implemented for the verification of targeted relationships among them. Western blotting was employed to measure the levels of pro-apoptotic proteins (Caspase3 and Caspase9).

RESULTS

The viability of LPS-induced chondrocytes was overtly promoted by loss of LINC01094 or miR-577 upregulation, but could be repressed via MTF1 overexpression. The opposite results were observed in apoptosis rate and the levels of Caspase3 and Caspase9. LINC01094 directly bound to miR-577, while MTF1 was verified to be modulated by miR-577. Both LINC01094 and MTF1 were at high levels, whereas miR-577 was at low level in OA synovial fluid and LPS-induced chondrocytes. Furthermore, the highly expressed miR-577 abolished the influences of MTF1 overexpression on LPS-induced chondrocytes.

CONCLUSIONS

Silencing of LINC01094 represses the apoptosis of chondrocytes through upregulating miR-577 expression and downregulating MTF1 levels, providing a preliminary insight for the treatment of OA in the future.

Functional and Molecular Analysis of Human Osteoarthritic Chondrocytes Treated with Bone Marrow-Derived MSC-EVs

Osteoarthritis (OA) is a degenerative joint disease, causing impaired mobility. There are currently no effective therapies other than palliative treatment. Mesenchymal stromal cells (MSCs) and their secreted extracellular vesicles (MSC-EVs) have shown promise in attenuating OA progression, promoting chondral regeneration, and modulating joint inflammation. However, the precise molecular mechanism of action driving their beneficial effects has not been fully elucidated. In this study, we analyzed MSC-EV-treated human OA chondrocytes (OACs) to assess viability, proliferation, migration, cytokine and catabolic protein expression, and microRNA and mRNA profiles. We observed that MSC-EV-treated OACs displayed increased metabolic activity, proliferation, and migration compared to the controls. They produced decreased proinflammatory (Il-8 and IFN-γ) and increased anti-inflammatory (IL-13) cytokines, and lower levels of MMP13 protein coupled with reduced expression of MMP13 mRNA, as well as negative microRNA regulators of chondrogenesis (miR-145-5p and miR-21-5p). In 3D models, MSC-EV-treated OACs exhibited enhanced chondrogenesis-promoting features (elevated sGAG, ACAN, and aggrecan). MSC-EV treatment also reversed the pathological impact of IL-1β on chondrogenic gene expression and extracellular matrix component (ECM) production. Finally, MSC-EV-treated OACs demonstrated the enhanced expression of genes associated with cartilage function, collagen biosynthesis, and ECM organization and exhibited a signature of 24 differentially expressed microRNAs, associated with chondrogenesis-associated pathways and ECM interactions. In conclusion, our data provide new insights on the potential mechanism of action of MSC-EVs as a treatment option for early-stage OA, including transcriptomic analysis of MSC-EV-treated OA, which may pave the way for more targeted novel therapeutics.

Intraarticular treatment with integrin α10β1-selected mesenchymal stem cells affects microRNA expression in experimental post-traumatic osteoarthritis in horses

Osteoarthritis (OA) remains a major cause of lameness in horses, which leads to lost days of training and early retirement. Still, the underlying pathological processes are poorly understood. MicroRNAs (miRNAs) are small non-coding RNAs that serve as regulators of many biological processes including OA. Analysis of miRNA expression in diseased joint tissues such as cartilage and synovial membrane may help to elucidate OA pathology. Since integrin α10β1-selected mesenchymal stem cell (integrin α10-MSC) have shown mitigating effect on equine OA we here investigated the effect of integrin α10-MSCs on miRNA expression. Cartilage and synovial membrane was harvested from the middle carpal joint of horses with experimentally induced, untreated OA, horses with experimentally induced OA treated with allogeneic adipose-derived MSCs selected for the marker integrin α10-MSCs, and from healthy control joints. miRNA expression in cartilage and synovial membrane was established by quantifying 70 pre-determined miRNAs by qPCR. Differential expression of the miRNAs was evaluated by comparing untreated OA and control, untreated OA and MSC-treated OA, and joints with high and low pathology score. A total of 60 miRNAs were successfully quantified in the cartilage samples and 55 miRNAs were quantified in the synovial membrane samples. In cartilage, miR-146a, miR-150 and miR-409 had significantly higher expression in untreated OA joints than in control joints. Expression of miR-125a-3p, miR-150, miR-200c, and miR-499-5p was significantly reduced in cartilage from MSC-treated OA joints compared to the untreated OA joints. Expression of miR-139-5p, miR-150, miR-182-5p, miR-200a, miR-378, miR-409-3p, and miR-7177b in articular cartilage reflected pathology score. Several of these miRNAs are known from research in human patients with OA and from murine OA models. Our study shows that these miRNAs are also differentially expressed in experimental equine OA, and that expression depends on OA severity. Moreover, MSC treatment, which resulted in less severe OA, also affected miRNA expression in cartilage.

Targeted delivery of miR125a-5p and human Factor VIII attenuates molecular mediators of hemophilic arthropathy

Hemophilic arthropathy (HA) due to repeated bleeding into the joint cavity is a major cause of morbidity in patients with hemophilia. The molecular mechanisms contributing to this condition are not well characterized. MicroRNAs (miRs) are known to modulate the phenotype of multiple joint diseases such as osteoarthritis (OA) and rheumatoid arthritis (RA). Since miR125a is known to modulate disease progression in OA and RA, we performed a targeted screen of miR125a-5p and its target genes in a murine model of chronic HA. A digital PCR analysis demonstrated significant downregulation of miR125a-5p (2-fold vs control joint). Further molecular evaluation revealed elevated expression of the immunological markers STAT1 (7.6-fold vs control joint) and TRAF6 (10.6 fold vs control joint), which are direct targets of miR125a-5p. We then studied the impact of targeted overexpression of miR125a-5p using an Adeno-associated virus (AAV) vector in modulating the molecular mediators of HA. AAV5-miR125a vectors were administered intra-articularly either alone or in combination with a low dose of AAV8-based human factor 8 (F8) gene in a murine model of HA. We observed significantly increased expression of miR125a-5p in AAV5-miR125a administered mice (~12 fold vs injured joint) or in combination with AAV8-F8 vectors (~44 fold vs injured joint). The activity assay revealed ~17 %-20 % FVIII levels in mice that received low dose liver-directed F8 gene therapy. Further immunohistochemical analysis, demonstrated a decrease in inflammatory markers (STAT1 and TRAF6) and cartilage-degrading matrix metalloproteinases (MMPs) 3, 9, 13 in the joints of treated animals. These data highlight the crucial role of miR125a-5p in the development of HA.

Paeoniflorin shows chondroprotective effects under IL-1β stress by regulating circ-PREX1/miR-140-3p/WNT5B axis

BACKGROUND

Osteoarthritis (OA) is a chronic and degenerative bone and joint disease, and paeoniflorin shows anti-arthritis role in OA. This study planned to investigate the mechanism related to chondroprotective role of paeoniflorin in OA.

METHODS

Real-time quantitative PCR and western blotting were performed to measure expression levels of circ-PREX1, microRNA (miR)-140-3p, Wingless-type MMTV integration site family, member 5B (WNT5B), B cell lymphoma (Bcl)-2, and Bcl-2 Associated X Protein (Bax). MTT assay, EdU assay, flow cytometry and enzyme-linked immunosorbent assay evaluated cell viability, proliferation, apoptosis and inflammatory response, respectively. Dual-luciferase reporter assay and RNA immunoprecipitation assay identified the relationship among circ-PREX1, miR-140-3p, and WNT5B.

RESULTS

IL-1β highly induced apoptosis rate, Bax expression and TNF-α product, accompanied with decreased cell viability, cell proliferation and IL-10 secretion, whereas these effects were partially reversed after paeoniflorin pretreatment. Expression of circ-PREX1 was upregulated and miR-140-3p was downregulated in cartilage tissues of patients with knee OA (KOA) and IL-1β-induced human chondrocytes (C28/I2). Circ-PREX1 overexpression and miR-140-3p silencing attenuated the suppressive effect of paeoniflorin in IL-1β-induced C28/I2 cells. Furthermore, miR-140-3p was negatively regulated by circ-PREX1. WNT5B was a downstream target of miR-140-3p and could be modulated by the circ-PREX1/miR-140-3p pathway in IL-1β-induced C28/I2 cells.

CONCLUSION

Paeoniflorin might protect human chondrocytes from IL-1β-induced inflammatory injury via circ-PREX1-miR-140-3p-WNT5B pathway, suggesting a potential preventative agent and a novel target for the treatment of KOA.

Circ_0136474 promotes the progression of osteoarthritis by sponging mir-140-3p and upregulating MECP2

BACKGROUND

Circular RNAs (circRNAs) have pivotal roles in the progression of many diseases, including osteoarthritis (OA). The detained function and regulatory mechanism of circ_0136474 in OA are still largely unknown.

METHODS

The chondrocytes (CHON-001 cells) were exposed to interleukin-1 beta (IL-1β) to mimic the injury in OA. The expression levels of circ_0136474, microRNA-140-3p (miR-140-3p), methyl-CpG-binding protein 2 (MECP2) mRNA were measured by qRT-PCR. Cell proliferation was assessed using CCK-8 assay. Flow cytometry was employed for measuring cell apoptosis. All protein levels were evaluated via western blot analysis. ELISA was used for detecting the concentrations of the inflammatory cytokines. Dual-luciferase reporter analysis and RNA Immunoprecipitation analysis were conducted for confirming the association between miR-140-3p and circ_0136474 or MECP2.

RESULTS

Circ_0136474 was upregulated in IL-1β-induced CHON-001 cells and OA cartilage tissues. Circ_0136474 deficiency alleviated IL-1β-stimulated CHON-001 cell damage via enhancing cell proliferation and reducing extracellular matrix (ECM) degradation, apoptosis, and inflammation. Circ_0136474 was a sponge of miR-140-3p, and miR-140-3p inhibition reversed the roles of circ_0136474 knockdown in IL-1β-treated CHON-001 cells. Moreover, miR-140-3p directly targeted MECP2, and upregulation of miR-140-3p attenuated L-1β-triggered CHON-001 cell injury via targeting MECP2. Additionally, circ_0136474 regulated MECP2 level via sponging miR-140-3p.

CONCLUSION

Circ_0136474 knockdown alleviated IL-1β-triggered CHON-001 cell damage through modulation of miR-140-3p/MECP2 axis, indicating a new target for treatment of OA.

Epigenetics as a Therapeutic Target in Osteoarthritis

Osteoarthritis (OA) is a heterogenous, complex disease affecting the integrity of diarthrodial joints that, despite its high prevalence worldwide, lacks effective treatment. In recent years it has been discovered that epigenetics may play an important role in OA. Our objective is to review the current knowledge of the three classical epigenetic mechanisms-DNA methylation, histone post-translational modifications (PTMs), and non-coding RNA (ncRNA) modifications, including microRNAs (miRNAs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs)-in relation to the pathogenesis of OA and focusing on articular cartilage. The search for updated literature was carried out in the PubMed database. Evidence shows that dysregulation of numerous essential cartilage molecules is caused by aberrant epigenetic regulatory mechanisms, and it contributes to the development and progression of OA. This offers the opportunity to consider new candidates as therapeutic targets with the potential to attenuate OA or to be used as novel biomarkers of the disease.

Investigation of MicroRNA Biomarkers in Equine Distal Interphalangeal Joint Osteoarthritis

Osteoarthritis of the equine distal interphalangeal joint is a common cause of lameness. MicroRNAs from biofluids are promising biomarkers and therapeutic candidates. Synovial fluid samples from horses with mild and severe equine distal interphalangeal joint osteoarthritis were submitted for small RNA sequencing. The results demonstrated that miR-92a was downregulated in equine synovial fluid from horses with severe osteoarthritis and there was a significant increase in COMP, COL1A2, RUNX2 and SOX9 following miR-92a mimic treatment of equine chondrocytes in monolayer culture. This is the first equine study to evaluate the role of miR-92a in osteoarthritic chondrocytes in vitro.

Sodium propionate improves rheumatoid arthritis by inhibiting survivin mediated proliferation of fibroblast like synoviocytes by promoting miR-140-5p

BACKGROUND

Increased proliferation and impaired death of fibroblast-like synovial cells play an important role in the development of rheumatoid arthritis (RA). Survivin plays an important role in the prodromal stage and prognosis of RA and has been introduced as a biomarker of joint injury in RA patients. The purpose of this study was to explore whether propionate alleviates RA through miR-140-5p/survivin pathway.

METHODS

The synovial tissues of RA patients were collected to detect the expression levels of miR-140-5p and survivin; normal human fibroblast-like synovial cells (HLSs) and RA fibroblast-like synovial cells (RA-FLSs) were cultured and treated with 10 mM of sodium propionate (SP), then the expressions of miR-140-5p and survivin, cell viability and apoptosis were detected; collagen induced arthritis (CIA) rat model was constructed and treated with SP, then the tissue inflammation level and the expression levels of miR-140-5p and Survivin were detected.

RESULTS

The expression of miR-140-5p decreased in synovial tissues of RA patients and RA-FLSs cells, while the expression of survivin increased significantly in RA patients. SP promoted miR-140-5p expression and apoptosis in RA-FLSs cells and inhibited survivin expression and cell viability of RA-FLSs cells. In addition, miR-140-5p plays a protective role by targeting survivin. Importantly, in the CIA rat model, SP reduced joint inflammatory response, and the miR-140-5p inhibitor weakened the protective effect of SP.

CONCLUSION

SP can alleviate RA by promoting the expression of miR-140-5p and inhibiting the excessive proliferation and death impairment of RA-FLSs cells induced by survivin.

Exosomal microRNA-140-3p from human umbilical cord mesenchymal stem cells attenuates joint injury of rats with rheumatoid arthritis by silencing SGK1

OBJECTIVE

Over the years, microRNAs (miRNAs) have been involved in the pathogenesis of rheumatoid arthritis (RA). We aim to investigate the role of human umbilical cord mesenchymal stem cells (HUCMSCs)-derived exosomal miR-140-3p in RA development.

METHODS

Exosomes(exo) were isolated from human umbilical cord-derived mesenchymal stem cells (HUCMSCs), and this isolation was followed by the transfer of miR-140-3p. RA rat models were constructed by collagen II adjuvant and respectively treated with HUCMSCs-exo or HUCMSCs-exo carrying miR-140-3p mimic/inhibitor, and expression of miR-140-3p and serum- and glucocorticoid-inducible kinase 1 (SGK1) was assessed. Then, RA score and inflammation scoring, fibrosis degree and apoptosis, serum inflammatory response and oxidative stress in joint tissues were determined. The RA synovial fibroblasts (RASFs) were extracted from rats and identified. Conducted with relative treatment, the migration, proliferation and apoptosis in RASFs were determined.

RESULTS

MiR-140-3p was decreased while SGK1 was increased in RA rats. HUCMSCs-exo or upregulated exosomal miR-140-3p improved pathological changes and suppressed inflammation, oxidative stress and fibrosis in RA rats, and also constrained and RASF growth. Overexpression of SGK1 reversed the inhibition of RASF growth caused by overexpression of miR-140-3p.

CONCLUSION

Upregulated exosomal miR-140-3p attenuated joint injury of RA rats by silencing SGK1. This research provided further understanding of the role of exosomal miR-140-3p in RA development.

Fluid shear stress-induced down-regulation of microRNA-140-5p promotes osteoblast proliferation by targeting VEGFA via the ERK5 pathway

PURPOSE

Fluid shear stress (FSS) plays a critical role in osteoblast proliferation. However, the role of miRNA in osteoblast proliferation induced by FSS and the possible molecular mechanisms remain to be defined. The aim of the present study was to investigate whether miR-140-5p regulates osteoblast proliferation under FSS and its molecular mechanism.

MATERIALS AND METHODS

miR-140-5p expression was measured by qRT-PCR. Western blot was used to measure the expressions of P-ERK1/2, ERK1/2, P-ERK5 and ERK5. The levels of VEGFA, PCNA, CDK4 and Cyclin D1 were identified through qRT-PCR and western blot, respectively. Cell proliferation was detected by CCK-8 assay and EdU labeling assay. Dual-luciferase reporter assay was used to validate the target of miR-140-5p.

RESULTS

miR-140-5p was significantly down-regulated when MC3T3-E1 cells were exposed to FSS. We then confirmed that up-regulation of miR-140-5p inhibited and down-regulation of miR-140-5p promoted osteoblast proliferation. In addition, FSS promotes osteoblast proliferation via down-regulating miR-140-5p. Luciferase reporter assay demonstrated that VEGFA is a direct target of miR-140-5p. Furthermore, transfection of mimic-140-5p inhibited the up-regulation of VEGFA protein level induced by FSS, suggesting that FSS regulates VEGFA protein expression via miR-140-5p. Further investigations demonstrated that VEGFA could promote osteoblast proliferation. Lastly, we demonstrated that miR-140-5p regulates osteoblast proliferation and ERK5 activation through VEGFA.

CONCLUSIONS

Our study demonstrates that FSS-induced the down-regulation of miR-140-5p promotes osteoblast proliferation through activing VEGFA/ERK5 signaling pathway. These findings may provide a novel mechanism of FSS-induced osteoblast proliferation and offer a new avenue to further investigate osteogenesis induced by mechanical loading.

microRNA-211-5p predicts the progression of postmenopausal osteoporosis and attenuates osteogenesis by targeting dual specific phosphatase 6

Postmenopausal osteoporosis (PMOP) is known as one of the prevalent diseases among middle-aged and elderly women. This paper revolves around the alteration of miR-211-5p in PMOP patients and its function in osteogenic differentiation. Quantitative real-time polymerase chain reaction (qRT-PCR) was implemented to check the miR-211-5p level in the plasma of PMOP patients. Knockdown and overexpression experiments were done to verify the influence of miR-211-5p on human-derived mesenchymal stem cell (hMSC) osteogenic differentiation and osteogenesis. The alkaline phosphatase (ALP) assay kit was taken to test ALP activity. Alizarin red staining monitored osteogenic differentiation, while oil red O staining examined adipogenesis. Western blot confirmed the profiles of osteoclastogenesis-concerned factors (TRAP, NFAT2, c-FOS, Runx2, OCN, CTSK), dual specific phosphatase 6 (DUSP6), ERK, SMAD, and β-catenin. Dual-luciferase reporter and RNA immunoprecipitation assays were implemented to identify the association between miR-211-5p and DUSP6. Our data displayed that miR-211-5p was down-regulated in the PMOP patients’ plasma (in contrast with the healthy controls), and it was positively correlated with Vit-D and BMD levels. miR-211-5p overexpression vigorously facilitated hMSC osteogenic differentiation, while miR-211-5p inhibition contributed to the opposite situation. miR-211-5p initiated the ERK/SMAD/β-catenin pathway and repressed DUSP6’s expression. Overexpression of DUSP6 counteracted the miR-211-5p-mediated function to a great extent and inactivated ERK/SMAD/β-catenin, whereas enhancing ERK phosphorylation weakened the DUSP6 overexpression-induced function. Consequently, this research unveiled that miR-211-5p promotes osteogenic differentiation by interfering with the DUSP6-mediated ERK/SMAD/β-catenin pathway.

CircSCAPER contributes to IL-1β-induced osteoarthritis in vitro via miR-140-3p/EZH2 axis

Aims

Circular RNA (circRNA) S-phase cyclin A-associated protein in the endoplasmic reticulum (ER) (circSCAPER, ID: hsa_circ_0104595) has been found to be highly expressed in osteoarthritis (OA) patients and has been associated with the severity of OA. Hence, the role and mechanisms underlying circSCAPER in OA were investigated in this study.

Methods

In vitro cultured human normal chondrocyte C28/I2 was exposed to interleukin (IL)-1β to mimic the microenvironment of OA. The expression of circSCAPER, microRNA (miR)-140-3p, and enhancer of zeste homolog 2 (EZH2) was detected using quantitative real-time polymerase chain reaction and Western blot assays. The extracellular matrix (ECM) degradation, proliferation, and apoptosis of chondrocytes were determined using Western blot, cell counting kit-8, and flow cytometry assays. Targeted relationships were predicted by bioinformatic analysis and verified using dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. The levels of phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway-related protein were detected using Western blot assays.

Results

CircSCAPER was highly expressed in OA cartilage tissues and IL-1β-induced chondrocytes. Knockdown of circSCAPER reduced IL-1β-evoked ECM degradation, proliferation arrest, and apoptosis enhancement in chondrocytes. Mechanistically, circSCAPER directly bound to miR-140-3p, and miR-140-3p inhibition reversed the effects of circSCAPER knockdown on IL-1β-induced chondrocytes. miR-140-3p was verified to target EZH2, and overexpression of miR-140-3p protected chondrocytes against IL-1β-induced dysfunction via targeting EZH2. Additionally, we confirmed that circSCAPER could regulate EZH2 through sponging miR-140-3p, and the circSCAPER/miR-140-3p/EZH2 axis could activate the PI3K/AKT pathway.

Conclusion

CircSCAPER promoted IL-1β-evoked ECM degradation, proliferation arrest, and apoptosis enhancement in chondrocytes via regulating miR-140-3p/EZH2 axis, which gained a new insight into the pathogenesis of OA.

Cite this article: Bone Joint Res 2022;11(2):61–72.

MicroRNA-140-5p represses chondrocyte pyroptosis and relieves cartilage injury in osteoarthritis by inhibiting cathepsin B/Nod-like receptor protein 3

Osteoarthritis (OA) is a degenerative joint disease. Dysregulated microRNA (miRNA) expressions are implicated in OA progression. Consequently, the current study set out to investigate the mechanism of miR-140-5p in OA cartilage injury. Firstly, the murine and cell models of OA were established, and cartilage tissues of OA mice were observed using hematoxylin and eosin staining and safranin O staining. Chondrocyte pyroptosis was further assessed using immunohistochemical and Calcein-AM/PI staining. The levels of gasdermin-D (GSDMD)-N, cleaved caspase-1, interleukin (IL)-1β, and IL-18 in cartilage tissues and cells were determined using Western blot and enzyme-linked immunosorbent assay kits. The targeting relationship between miR-140-5p and cathepsin B (CTSB) was verified using a dual-luciferase assay. Moreover, the binding of CTSB and Nod-like receptor protein 3 (NLRP3) was detected using co-immunoprecipitation assay. Lastly, the effects of NLRP3 activation and CTSB overexpression on chondrocyte pyroptosis were documented. It was found that OA induction aggravated cartilage tissue injury and enhanced chondrocyte pyroptosis. miR-140-5p was poorly-expressed in OA models, and miR-140-5p over-expression alleviated chondrocyte pyroptosis, as evidenced by decreased GSDMD-N, cleaved caspase-1, IL-1β, and IL-18 levels. miR-140-5p targeted the CTSB gene, whereas CTSB further bound to NLRP3 and activated the NLRP3 inflammasome. Additionally, CTSB over-expression or NLRP3 activation reversed the inhibitory effect of miR-140-5p on chondrocyte pyroptosis. Collectively, our findings revealed that miR-140-5p repressed chondrocyte pyroptosis and alleviated OA cartilage injury via inhibition of the CTSB/NLRP3. This study may confer a theoretical basis for the treatment of OA cartilage injury.

Synovial Fluid Biomarkers in Knee Osteoarthritis: A Systematic Review and Quantitative Evaluation Using BIPEDs Criteria

OBJECTIVE

The aim of this systematic review was to analyze the evidence about the efficacy of the several synovial fluid (SF) biomarkers proposed for knee osteoarthritis (OA), categorizing them by both molecular characteristics and clinical use according to the BIPEDs criteria, to provide a comprehensive and structured overview of the current literature.

DESIGN

A systematic review was performed in May 2020 on PubMed, Cochrane Library, and Embase databases about SF biomarkers in patients with knee OA. The search was limited to articles in the last 20 years on human studies, involving patients with knee OA, reporting SF biomarkers. The evidence for each selected SF biomarker was quantified according to the 6 categories of BIPEDs classification.

RESULTS

A total of 159 articles were included in the qualitative data synthesis and 201 different SF biomarkers were identified. Among these, several were investigated multiple times in different articles, for a total of 373 analyses. The studies included 13,557 patients with knee OA. The most promising SF biomarkers were C4S, IL-6, IL-8, Leptin, MMP-1/3, TIMP-1, TNF-α, and VEGF. The "burden of disease" and "diagnostic" categories were the most represented with 132 and 106 different biomarkers, respectively.

CONCLUSIONS

The systematic review identified numerous SF biomarkers. However, despite the high number of studies on the plethora of identified molecules, the evidence about the efficacy of each biomarker is supported by limited and often conflicting findings. Further research efforts are needed to improve the understanding of SF biomarkers for a better management of patients with knee OA.

LINC01534 Promotes the Aberrant Metabolic Dysfunction and Inflammation in IL-1β-Simulated Osteoarthritic Chondrocytes by Targeting miR-140-5p

OBJECTIVE

Long non-coding RNA 01534 (LINC01534) is highly expressed in the tissues of patients with osteoarthritis (OA). This study investigated the mechanism of LINC01534 on abnormal metabolic dysfunction in OA chondrocytes induced by interleukin-1β (IL-1β).

METHODS

The quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine the expressions of LINC01534, aggrecan, collagen II, and matrix metalloproteinase (MMPs) in OA cartilage tissue or OA chondrocyte model induced by IL-1β. The expressions of aggrecan and collagen II in the chondrocyte were detected by Western blot. The levels of tumor necrosis factor-α (TNF-α), IL-8, IL-6, MMP-13, MMP-9, MMP-3, and prostaglandin E2 (PGE2) in chondrocyte were determined by enzyme-linked immunosorbernt assay. Bioinformatics, dual luciferin gene reporting, RNA pulldown, and Northern blot were used to determine the interaction between LINC01534 and miR-140-5p.

RESULTS

The results showed that LINC01534 was upregulated in both OA cartilage tissue and OA chondrocyte model. In addition, silencing LINC01534 significantly alleviated the inhibitory effect of IL-1β on expressions of aggrecan and collagen II in chondrocytes, and significantly downregulated the expression of matrix metalloproteinases in IL-1β-induced chondrocytes. Meanwhile, silencing LINC01534 also significantly inhibited the productions of proinflammatory factors NO, PGE2, TNF-α, IL-6, and IL-8 in the IL-1β-induced chondrocytes. Furthermore, miR-140-5p was confirmed to be a direct target of LINC01534. More importantly, inhibition of miR-140-5p significantly reversed the inhibitory effect of silencing LINC01534 on abnormal matrix degradation in the IL-1β-induced chondrocyte model of OA.

CONCLUSION

Therefore, LINC01534 could promote the abnormal matrix degradation and inflammatory response of OA chondrocytes through the targeted binding of miR-140-5p.

Integrative Analysis of the Expression of microRNA, Long Noncoding RNA, and mRNA in Osteoarthritis and Construction of a Competing Endogenous Network

This study aimed to identify potential core microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and mRNAs in osteoarthritis (OA) to construct a competing endogenous RNA (ceRNA) and co-expression network. Differentially expressed miRNAs (DEMis) in the dataset GSE143514 comprising five OA and three normal tissues were identified using the DEseq package. Core miRNAs were identified as DEMis overlapping with those reported by the human microRNA disease database. LncRNAs were predicted by the miRNA-lncRNA interactions network from the encyclopedia of RNA interactomes (ENCORI). MiRNet and ENCORI were employed to predict the mRNAs which overlapped with the differentially expressed mRNAs from the dataset GSE114007 to obtain overlapping mRNAs. MiRNA-lncRNA and miRNA-mRNA interactions were integrated to construct the ceRNA network. A total of 143 DEMis were identified in OA and normal tissues, from which hsa-miR-451a, hsa-miR-370-5p, hsa-miR-34a-5p, hsa-miR-210-3p, and hsa-miR-101-3p were assessed as core miRNAs using overlapping analyses. These RNAs may represent potential therapeutic targets for the treatment of OA.

Efficacy of small-dose ganciclovir on cytomegalovirus infections in children and its effects on liver function and miR-UL112-3p expression

The aim of the study was to explore the efficacy of small-dose ganciclovir on cytomegalovirus infections as well as its effects on the liver function and miR-UL112-3p of children. A total of 141 children infected with cytomegalovirus admitted to the Affiliated Hospital of Weifang Medical University from May 2015 to August 2017 were enrolled, of which 74 children were treated with small-dose ganciclovir as an observation group (Obs group), and the rest were treated with conventional-dose ganciclovir as a control group (Con group). The two groups were compared in efficacy after treatment, changes of liver function indexes [total bilirubin (TB), alanine aminotransferase (ALT), and aspartate aminotransferase (AST)] and miR-UL112-3p before and after treatment, and adverse reactions after treatment. A receiver operating characteristic (ROC) curve was drawn to analyze the value of miR-UL112-3p in predicating efficacy on cytomegalovirus infections in children, and Pearson's correlation analysis was carried out to analyze the correlation between miR-UL112-3p expression and TB, ALT and AST. The MV-DNA level between the two groups after treatment was compared. The two groups showed no significant difference in efficacy and adverse reactions (both P>0.05), and before treatment, there was also no significant difference between the two groups in miR-UL112-3p, TB, ALT, and AST, while after treatment, both groups showed lower levels of miR-UL112-3p, TB, ALT, and AST, and the Obs group showed significantly lower levels thereof than the Con group (all P<0.05). In addition, the area under the curve (AUC), specificity, and sensitivity of miR-UL112-3p in the ROC curve of the Obs group were 0.866, 73.77 and 84.62%, respectively, while the AUC, specificity, and sensitivity of the ROC of the Con group were 0.837, 75.44, and 90.00%, respectively. Furthermore, miR-UL112-3p was positively correlated with TB, ALT, and AST, respectively. The CMV-DNA level in the Obs group was lower than that in the Con group, but the difference was not significant, and the level of CMV-DNA was positively correlated with that of miR-UL112-3p. In conclusion, small-dose ganciclovir can better improve the liver function of the children, and downregulate miR-UL112-3p in them. The AUC, specificity, and sensitivity of miR-UL112-3p for predicting the efficacy of small-dose ganciclovir were 0.866, 73.77 and 84.62%, respectively, and the AUC, specificity, and sensitivityfor predicting the efficacy of conventional-dose ganciclovir were 0.837, 75.44 and 90.00%, respectively.

CircMAPK9 promotes the progression of fibroblast-like synoviocytes in rheumatoid arthritis via the miR-140-3p/PPM1A axis

Background

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease, and fibroblast-like synoviocytes (FLSs) are key effector cells in RA development. Mounting evidence indicates that circular RNAs (circRNAs) participate in the occurrence and development of RA. However, the precise mechanism of circRNA mitogen-activated protein kinase (circMAPK9) in the cell processes of FLSs has not been reported.

Methods

The expression levels of circMAPK9, microRNA-140-3p (miR-140-3p), and protein phosphatase magnesium-dependent 1A (PPM1A) were determined by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot assay. Cell proliferation was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell apoptosis and cycle distribution were assessed by flow cytometry. Cell migration and invasion were tested by transwell assay. All the proteins were inspected by western blot assay. Inflammatory response was evaluated by enzyme-linked immunosorbent assay (ELISA). The interaction between miR-140-3p and circMAPK9 or PPM1A was verified by dual-luciferase reporter assay.

Results

CircMAPK9 and PPM1A were upregulated and miR-140-3p was downregulated in RA patients and FLSs from RA patients (RA-FLSs). CircMAPK9 silence suppressed cell proliferation, migration, invasion, inflammatory response, and promoted apoptosis in RA-FLSs. MiR-140-3p was a target of circMAPK9, and miR-140-3p downregulation attenuated the effects of circMAPK9 knockdown on cell progression and inflammatory response in RA-FLSs. PPM1A was targeted by miR-140-3p, and circMAPK9 could regulate PPM1A expression by sponging miR-140-3p. Furthermore, miR-140-3p could impede cell biological behaviors in RA-FLSs via targeting PPM1A.

Conclusion

CircMAPK9 knockdown might inhibit cell proliferation, migration, invasion, inflammatory response, and facilitate apoptosis in RA-FLSs via regulating miR-140-3p/PPM1A axis, offering a new mechanism for the comprehension of RA development and a new insight into the potential application of circMAPK9 in RA treatment.

Piperine treating sciatica through regulating inflammation and MiR-520a/P65 pathway

Although the etiology of sciatica remains uncertain, there is increasing evidence that the disease process of sciatica is associated with the levels of inflammatory factors. Piperine, an alkaloid isolated from Piper nigrum, has previously been demonstrated to inhibit inflammation and analgesic effects. The purpose of this study is to verify the regulatory relationship between miR-520a and p65 and to explore how miR-520a/P65 affects the level of cytokines under the action of piperine, so as to play a therapeutic role in sciatica. Through ELISA experiment, we confirmed that four inflammatory factors (IL-1β, TNF-α, IL-10, TGF-β1) can be used as evaluation indexes of sciatica. The differentially expressed miRNA was screened as miR-520a, by microarray technology, and the downstream target of miR-520a was P65 by bioinformatics. Real-time fluorescence quantitative PCR confirmed that the expression of miR-520a was negatively correlated with pro-inflammatory cytokines, positively correlated with anti-inflammatory cytokines and negatively correlated with p65 expression at mRNA level. The expression of p65 was positively correlated with pro-inflammatory cytokines and negatively correlated with anti-inflammatory cytokines at the protein level verified by ELISA and Western blot. HE staining analysis showed that the nerve fibers were repaired by piprine, the vacuoles were significantly reduced, and the degree of nerve fiber damage was also improved. Immunohistochemical analysis showed that the expression of p65 decreased after administration of piperine. Dual-luciferase reporter gene assay confirmed that the luciferase signal decreased significantly after cotransfection of miR-520a mimics and p65 3'UTR recombinant plasmid. To sum up, in the rat model of non-compressed lumbar disc herniation, piperine plays a significant role in analgesia. MiR-520a can specifically and directly target P65, and piperine can promote the expression of miR-520a, then inhibit the expression of p65, down-regulate the pro-inflammatory factors IL-1β and TNF-α, and up-regulate the effects of anti-inflammatory factors IL-10 and TGF-β1, so as to treat sciatica.

DNA Methylation Signatures of Bone Metabolism in Osteoporosis and Osteoarthritis Aging-Related Diseases: An Updated Review

DNA methylation is one of the most studied epigenetic mechanisms that play a pivotal role in regulating gene expression. The epigenetic component is strongly involved in aging-bone diseases, such as osteoporosis and osteoarthritis. Both are complex multi-factorial late-onset disorders that represent a globally widespread health problem, highlighting a crucial point of investigations in many scientific studies. In recent years, new findings on the role of DNA methylation in the pathogenesis of aging-bone diseases have emerged. The aim of this systematic review is to update knowledge in the field of DNA methylation associated with osteoporosis and osteoarthritis, focusing on the specific tissues involved in both pathological conditions.

MicroRNA-197 regulates chondrocyte proliferation, migration, and inflammation in pathogenesis of osteoarthritis by targeting EIF4G2

Recent studies have demonstrated that microRNAs (miRNAs) are involved in many pathological conditions including osteoarthritis (OA). In the present study, we aimed to investigate the role of miR-197 in OA and the potential molecular mechanism. The expression levels of miR-197 were detected by quantitative real-time PCR analysis. Cell proliferation and migration abilities were performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-di-phenyltetrazolium bromide and transwell assays. The concentrations of inflammatory cytokines, including IL-1β, IL-6, and TNF-α, were detect using ELISA assay. Furthermore, luciferase reporter and rescue assays were applied to identify the functional target gene of miR-197 in OA. The results showed that miR-197 expression was significantly down-regulated in the OA cartilage tissues compared with normal cartilage tissues, accompanied by up-regulation of EIF4G2 expression. An inverse correlation was found between EIF4G2 and miR-197 expressions in OA cartilage tissues. Treatment with miR-197 mimics promoted the growth and migration abilities of chondrocytes, while miR-197 inhibitors induced the opposite effects. Furthermore, restoration of miR-197 significantly decreased IL-1β, IL-6, and TNF-α expression, whereas knockdown of miR-197 led to a induction in these inflammatory mediators. Moreover, EIF4G2 was predicted and confirmed as a directly target of miR-197. Overexpressed miR-197 could down-regulate EIF4G2 expression in chondrocytes, while miR-197 knockdown could elevate EIF4G2 expression. Additionally, EIF4G2 overexpression reversed the effects of miR-197 mimics on chondrocytes proliferation, migration, and inflammation. Taken together, our study demonstrated that miR-197 promotes chondrocyte proliferation, increases migration, and inhibits inflammation in the pathogenesis of OA by targeting EIF4G2, indicating the potential therapeutic targets of the miR-197/EIF4G2 axis for OA treatment.

Significant Changes in Serum MicroRNAs after High Tibial Osteotomy in Medial Compartmental Knee Osteoarthritis: Potential Prognostic Biomarkers

High tibial osteotomy (HTO) is an effective alternative for medial compartmental knee osteoarthritis (OA). Circulating microRNAs (miRNAs) are known to serve as OA-related biomarkers. The present study investigated the differential expression of serum miRNAs before and after HTO to identify potential miRNAs as prognostic biomarkers. miRNA-polymerase chain reaction (PCR) arrays were used to screen for miRNAs in the serum at preoperative and 6-month postoperative time points from six patients, and the differentially expressed miRNAs identified in the profiling stage were validated using real-time PCR at post-operative months 6 and 18 in 27 other HTO-treated patients. Among 84 miRNAs involved in the inflammatory process, three (miR-19b-3p, miR-29c-3p, and miR-424-5p) showed differential expression patterns in the profiling stage (p = 0.011, 0.015, and 0.021, respectively). Levels of these three and four other miRNAs (miR-140-3p, miR-454-3p, miR-let-7e-5p, and miR-885-5p) known to be related to OA progression were evaluated in the serum of 27 patients. Only four miRNAs (miR-19b-3p, miR-140-3p, miR-454-3p, and miR-let-7e-5p) were significantly upregulated at postoperative month 6 (p = 0.003, 0.005, 0.004, and 0.004, respectively), and only miR-140-3p was significantly upregulated up to 18 months after operation (p = 0.003). Together, this study reveals the significantly upregulated serum miRNAs after HTO as potential prognostic biomarkers; however, further studies are warranted to elucidate their clinical implications.

Equine synovial fluid small non-coding RNA signatures in early osteoarthritis

BACKGROUND

Osteoarthritis remains one of the greatest causes of morbidity and mortality in the equine population. The inability to detect pre-clinical changes in osteoarthritis has been a significant impediment to the development of effective therapies against this disease. Synovial fluid represents a potential source of disease-specific small non-coding RNAs (sncRNAs) that could aid in the understanding of the pathogenesis of osteoarthritis. We hypothesised that early stages of osteoarthritis would alter the expression of sncRNAs, facilitating the understanding of the underlying pathogenesis and potentially provide early biomarkers.

METHODS

Small RNA sequencing was performed using synovial fluid from the metacarpophalangeal joints of both control and early osteoarthritic horses. A group of differentially expressed sncRNAs was selected for further validation through qRT-PCR using an independent cohort of synovial fluid samples from control and early osteoarthritic horses. Bioinformatic analysis was performed in order to identify putative targets of the differentially expressed microRNAs and to explore potential associations with specific biological processes.

RESULTS

Results revealed 22 differentially expressed sncRNAs including 13 microRNAs; miR-10a, miR-223, let7a, miR-99a, miR-23b, miR-378, miR-143 (and six novel microRNAs), four small nuclear RNAs; U2, U5, U11, U12, three small nucleolar RNAs; U13, snoR38, snord96, and one small cajal body-specific RNA; scarna3. Five sncRNAs were validated; miR-223 was significantly reduced in early osteoarthritis and miR-23b, let-7a-2, snord96A and snord13 were significantly upregulated. Significant cellular actions deduced by the differentially expressed microRNAs included apoptosis (P < 0.0003), necrosis (P < 0.0009), autophagy (P < 0.0007) and inflammation (P < 0.00001). A conservatively filtered list of 57 messenger RNA targets was obtained; the top biological processes associated were regulation of cell population proliferation (P < 0.000001), cellular response to chemical stimulus (P < 0.000001) and cell surface receptor signalling pathway (P < 0.000001).

CONCLUSIONS

Synovial fluid sncRNAs may be used as molecular biomarkers for early disease in equine osteoarthritic joints. The biological processes they regulate may play an important role in understanding early osteoarthritis pathogenesis. Characterising these dynamic molecular changes could provide novel insights on the process and mechanism of early osteoarthritis development and is critical for the development of new therapeutic approaches.

Synovial fluid fingerprinting in end-stage knee osteoarthritis: a novel biomarker concept

Aims

The lack of disease-modifying treatments for osteoarthritis (OA) is linked to a shortage of suitable biomarkers. This study combines multi-molecule synovial fluid analysis with machine learning to produce an accurate diagnostic biomarker model for end-stage knee OA (esOA).

Methods

Synovial fluid (SF) from patients with esOA, non-OA knee injury, and inflammatory knee arthritis were analyzed for 35 potential markers using immunoassays. Partial least square discriminant analysis (PLS-DA) was used to derive a biomarker model for cohort classification. The ability of the biomarker model to diagnose esOA was validated by identical wide-spectrum SF analysis of a test cohort of ten patients with esOA.

Results

PLS-DA produced a streamlined biomarker model with excellent sensitivity (95%), specificity (98.4%), and reliability (97.4%). The eight-biomarker model produced a fingerprint for esOA comprising type IIA procollagen N-terminal propeptide (PIIANP), tissue inhibitor of metalloproteinase (TIMP)-1, a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4), monocyte chemoattractant protein (MCP)-1, interferon-γ-inducible protein-10 (IP-10), and transforming growth factor (TGF)-β3. Receiver operating characteristic (ROC) analysis demonstrated excellent discriminatory accuracy: area under the curve (AUC) being 0.970 for esOA, 0.957 for knee injury, and 1 for inflammatory arthritis. All ten validation test patients were classified correctly as esOA (accuracy 100%; reliability 100%) by the biomarker model.

Conclusion

SF analysis coupled with machine learning produced a partially validated biomarker model with cohort-specific fingerprints that accurately and reliably discriminated esOA from knee injury and inflammatory arthritis with almost 100% efficacy. The presented findings and approach represent a new biomarker concept and potential diagnostic tool to stage disease in therapy trials and monitor the efficacy of such interventions.Cite this article: Bone Joint Res 2020;9(9):623-632.

Bioinformatics analysis of microRNA linked to ubiquitin proteasome system in traumatic osteonecrosis of the femoral head

MicroRNAs (miRNAs) have been suggested to act critical roles in the pathophysiology of traumatic osteonecrosis of the femoral head (TONFH). Unfortunately, their roles in the development of TONFH are still ambiguous. The purpose of this study is to identify promising miRNA biomarkers in traumatic osteonecrosis development.We conducted a comprehensive bioinformatics analysis using microarray datasets downloaded from the Gene Expression Omnibus database, and compared the expression of miRNAs in the serum of TONFH patients with controls. Next, we performed target prediction, function enrichment analysis, and protein-protein interaction network analysis based on differentially expressed (DE) miRNAs.We identified 26 DE miRNAs that may contribute to the pathophysiology of TONFH. The miRNAs were linked to ubiquitin proteasome system including conjugating protein ligase activity, ubiquitin-protein ligase activity and ubiquitin mediated proteolysis 5 pathway, and we exposed miR-181a-5p and miR-140-5p as promising biomarkers in TONFH.A predicting model consisting of 5 miRNAs may help discriminating high-risk patients who might develop TONFH after femur neck fracture. Among DE miRNAs, MiR-181a-5p and miR-140-5p may contribute to the development femoral head osteonecrosis after femur neck fracture via ubiquitin proteasome system.

Promising targets and drugs in rheumatoid arthritis: a module-based and cumulatively scoring approach

AIMS

Rheumatoid arthritis (RA) is a systematic autoimmune disorder, characterized by synovial inflammation, bone and cartilage destruction, and disease involvement in multiple organs. Although numerous drugs are employed in RA treatment, some respond little and suffer from severe side effects. This study aimed to screen the candidate therapeutic targets and promising drugs in a novel method.

METHODS

We developed a module-based and cumulatively scoring approach that is a deeper-layer application of weighted gene co-expression network (WGCNA) and connectivity map (CMap) based on the high-throughput datasets.

RESULTS

Four noteworthy RA-related modules were identified, revealing the immune- and infection-related biological processes and pathways involved in RA. HLA-DMA, HLA-DMB, HLA-DPA1, HLA-DPB1, HLA-DQB1, HLA-DRA, HLA-DRB1, BLNK, BTK, CD3D, CD4, IL2RG, INPP5D, LCK, PTPRC, RAC2, SYK, and VAV1 were recognized as the key hub genes with high connectivity in gene regulation networks and gene pathway networks. Moreover, the long noncoding RNAs (lncRNAs) in the RA-related modules, such as FAM30A and NEAT1, were identified as the indispensable interactors with the hub genes. Finally, candidate drugs were screened by developing a cumulatively scoring approach based on the selected modules. Niclosamide and the other compounds of T-type calcium channel blocker, IKK inhibitor, and PKC activator, HIF activator, and proteasome inhibitor, which harbour the similar gene signature with niclosamide, were promising drugs with high specificity and broad coverage for the RA-related modules.

CONCLUSION

This study provides not only the promising targets and drugs for RA but also a novel methodological insight into the target and drug screening.Cite this article: Bone Joint Res 2020;9(8):501-514.

miR-140-3p Inhibits Cutaneous Melanoma Progression by Disrupting AKT/p70S6K and JNK Pathways through ABHD2

Because cutaneous melanoma (CM) is one of the most lethal human tumors, major treatment advances are vital. miR-140-3p has been suggested to act as a suppressor in a range of malignant tumors, implying its possible use as a biomarker for effective antineoplastic treatment. However, the potential role of miR-140-3p in CM and the underlying mechanism remain unclear. In the present study, we identified lower levels of miR-140-3p in both CM tissues and cell lines; this downregulation was strongly associated with worse CM survival. Additionally, overexpression of miR-140-3p significantly inhibited cell proliferation, migration, and invasion in CM cells with different cell line origins. Importantly, by means of both bioinformatics analysis and luciferase reporter assay, we revealed abhydrolase domain containing 2 (ABHD2) to be a target of miR-140-3p in CM cells. Upregulation of ABHD2 reversed the tumor-suppressive effects of miR-140-3p in CM cells. Furthermore, miR-140-3p-targeted ABHD2 played a role in both activation of JNK signaling and inhibition of the AKT/p70S6K pathway in CM cells. Finally, in vivo results strongly suggested the suppressive effects of miR-140-3p on CM growth and metastasis. Collectively, our findings highlight a novel antineoplastic function for miR-140-3p in CM through ABHD2.

An integrated analysis of the competing endogenous RNA network and co-expression network revealed seven hub long non-coding RNAs in osteoarthritis

Aims

This study aimed to uncover the hub long non-coding RNAs (lncRNAs) differentially expressed in osteoarthritis (OA) cartilage using an integrated analysis of the competing endogenous RNA (ceRNA) network and co-expression network.

Methods

Expression profiles data of ten OA and ten normal tissues of human knee cartilage were obtained from the Gene Expression Omnibus (GEO) database (GSE114007). The differentially expressed messenger RNAs (DEmRNAs) and lncRNAs (DElncRNAs) were identified using the edgeR package. We integrated human microRNA (miRNA)-lncRNA/mRNA interactions with DElncRNA/DEmRNA expression profiles to construct a ceRNA network. Likewise, lncRNA and mRNA expression profiles were used to build a co-expression network with the WGCNA package. Potential hub lncRNAs were identified based on an integrated analysis of the ceRNA network and co-expression network. StarBase and Multi Experiment Matrix databases were used to verify the lncRNAs.

Results

We detected 1,212 DEmRNAs and 49 DElncRNAs in OA and normal knee cartilage. A total of 75 dysregulated lncRNA-miRNA interactions and 711 dysregulated miRNA-mRNA interactions were obtained in the ceRNA network, including ten DElncRNAs, 69 miRNAs, and 72 DEmRNAs. Similarly, 1,330 dysregulated lncRNA-mRNA interactions were used to construct the co-expression network, which included ten lncRNAs and 407 mRNAs. We finally identified seven hub lncRNAs, named MIR210HG, HCP5, LINC00313, LINC00654, LINC00839, TBC1D3P1-DHX40P1, and ISM1-AS1. Subsequent enrichment analysis elucidated that these lncRNAs regulated extracellular matrix organization and enriched in osteoclast differentiation, the FoxO signalling pathway, and the tumour necrosis factor (TNF) signalling pathway in the development of OA.

Conclusion

The integrated analysis of the ceRNA network and co-expression network identified seven hub lncRNAs associated with OA. These lncRNAs may regulate extracellular matrix changes and chondrocyte homeostasis in OA progress.

Cite this article:Bone Joint Res. 2020;9(3):90–98.

[Study on effect of echinococcus granulosus protoscolices on fibrosis of bone marrow mesenchymal stem cells]

Objective

To investigate the effect of echinococcus granulosus protoscolices on the differentiation of bone marrow mesenchymal stem cells (BMSCs) into fibroblasts.

Methods

Femur bone marrow of 4-week-old C57BL/6 mice was taken and BMSCs were isolated and cultured by adherent culture. Echinococcus granulosus protoscolices was extracted from the liver of sheep infected with echinococcus granulosus. The experiment was divided into two groups. The experimental group was co-cultured with the 3rd generation BMSCs and the echinococcus granulosus protoscolices, and the control group was the 3rd generation BMSCs. Before and after co-culture, the morphology of BMSCs and the activity of echinococcus granulosus protoscolices were observed by inverted microscope. After cultured for 1, 3, 5, and 7 days, the mRNA expressions of transforming growth factor β ₁ (TGF-β ₁), collagen type Ⅰ, and collagen type Ⅲ were detected by real-time fluorescent quantitative PCR, the protein expressions of TGF-β ₁, collagen type Ⅰ, collagen type Ⅲ, Smad7, and phosphorylated Smad2/3 were detected by Western blot, and the contents of collagen type Ⅰ and collagen type Ⅲ in the supernatant of the two groups were detected by ELISA.

Results

After 7 days of co-culture, the morphology of BMSCs changed into fusiform and irregular triangle, which was closer to the mouse fibroblasts. The relative mRNA expressions of TGF-β ₁, collagen type Ⅰ, and collagen type Ⅲ in the experimental group were significantly higher than those in the control group; the relative protein expressions of TGF-β ₁, collagen type Ⅰ, collagen type Ⅲ, and phosphorylated Smad2/3 in the experimental group were significantly higher than those in the control group, and the relative protein expression of Smad7 in the experimental group was significantly lower than that in the control group; the contents of collagen type Ⅰ and collagen type Ⅲ in the supernatant of the experimental group were significantly higher than those in the control group. The differences between the two groups were significant ( P<0.05).

Conclusion

Echinococcus granulosus protoscolices may promote the secretion of collagen type Ⅰ, collagen type Ⅲ, and TGF-β ₁ by TGF-β ₁/Smad signal pathway, which can promote the fibrosis of BMSCs that related to the formation of fibrocystic wall by echinococcosis.

MiR-140-3p Ameliorates the Progression of Osteoarthritis via Targeting CXCR4

Osteoarthritis is a common disease character with progressive destruction of cartilage. MicroRNA (miR)-140-3p was validated as a biomarker for osteoarthritis. However, the mechanism by which miRNA-140-3p regulates osteoarthritis remains unclear. Thus, this study aims to evaluate the potential function of miRNA-140-3p during the pathogenesis of osteoarthritis. MiRNA-140-3p expression in tissue and CHON-001 chondrocyte cells was determined with quantitative real time (qRT)-PCR. In vitro osteoarthritis model was established by treatment of the chondrocyte cells CHON-001 with interleukin (IL)-1β. Cell proliferation and apoptosis were measured with cell counting kit-8 (CCK8) and Annexin V/propidium iodide (PI) apoptosis assay, respectively. Protein expressions were evaluated using Western blot. The target gene of miR-140-3p was predicted using Targetscan and miRDB. MiR-140-3p was downregulated in knee tissue from patients with osteoarthritis. IL-1β inhibited the proliferation of CHON-001 cells via inducing apoptosis. In addition, IL-1β significantly inhibited the expressions of collagen II and aggrecan and increased the level of matrix metalloproteinase (MMP)13. However, the effects of IL-1β could be ameliorated by the addition of miR-140-3p mimics. Moreover, luciferase reporter assay demonstrated CXCR4 as a target gene of miR-140-3p. IL-1β-induced upregulation of CXCR4 could be blocked by miR-140-3p mimics. Our study indicated that miR-140-3p could suppress the progression of osteoarthritis by directly targeting CXCR4. Therefore, miR-140-3p might serve as a potential therapeutic target for the treatment of osteoarthritis.

Significant changes in synovial fluid microRNAs after high tibial osteotomy in medial compartmental knee osteoarthritis: Identification of potential prognostic biomarkers

High tibial osteotomy (HTO) is a well-established treatment for medial compartmental knee osteoarthritis. Several microRNAs (miRNAs) are involved in osteoarthritis progression and are useful as osteoarthritis-related biomarkers. In this prospective study, we investigated differentially expressed microRNAs in the synovial fluid (SF) before and after HTO in patients with medial compartmental knee osteoarthritis to identify microRNAs that can be used as prognostic biomarkers. We used miRNA-PCR arrays to screen for miRNAs in SF samples obtained preoperatively and 6 months postoperatively from 6 patients with medial compartmental knee osteoarthritis who were treated with medial open wedge HTO. Differentially expressed miRNAs identified in the profiling stage were validated by real-time quantitative PCR in 22 other patients who had also been treated with HTO. All patients radiographically corresponded to Kellgren-Lawrence grade II or III with medial compartmental osteoarthritis. These patients were clinically assessed using a visual analogue scale and Western Ontario McMaster Universities scores. Mechanical axis changes were measured on standing anteroposterior radiographs of the lower limbs assessed preoperatively and at 6 months postoperatively. Among 84 miRNAs known to be involved in the inflammatory process, 14 were expressed in all SF specimens and 3 (miR-30a-5p, miR-29a-3p, and miR-30c-5p) were differentially expressed in the profiling stage. These 3 miRNAs, as well as 4 other miRNAs (miR-378a-5p, miR-140-3p, miR-23a-3p, miR-27b-3p), are related to osteoarthritis progression. These results were validated in the SF from 22 patients. Clinical and radiological outcomes improved after HTO in all patients, and only 2 miRNAs (miR-30c-5p and miR-23a-3p) were significantly differentially expressed between preoperative and postoperative 6-month SF samples (p = 0.006 and 0.007, respectively). Of these two miRNAs, miR-30c-5p correlated with postoperative pain relief. This study provides potential prognostic miRNAs after HTO and further investigations should be considered to determine clinical implications of these miRNAs.

The protective role of microRNA-140-5p in synovial injury of rats with knee osteoarthritis via inactivating the TLR4/Myd88/NF-κB signaling pathway

Objective: Recently, many studies have revealed the effect of microRNAs (miRNAs) in knee osteoarthritis (KOA). This study aims to explore the role of miR-140-5p in protective effects and mechanisms of synovial injury of rats with KOA via regulating the TLR4/Myd88/NF-κB signaling pathway.

Methods: The models of KOA Wistar rats were established by operation of anterior cruciate ligament transection. Rats were injected with agomir NC or miR-140-5p agomir. MiR-140-5p expression in KOA synovial tissues and synoviocytes was evaluated by reverse transcription quantitative polymerase chain reaction (RT-qPCR). The synoviocytes were transfected with mimics NC sequence and miR-140-5p mimics sequence. The expression of TLR4/Myd88/NF-κB signaling pathway-related proteins was measured by RT-qPCR and western blot analysis. The proliferation and apoptosis of synoviocytes in rats with KOA were evaluated by a string of experiments. The expression levels of inflammatory factors in KOA synovial tissues and synoviocytes were detected.

Results: MiR-140-5p was down-regulated in KOA synovial tissues and synoviocytes. Upregulation of miR-140-5p could inhibit the inflammation reaction and the apoptosis of synoviocytes as well as promote proliferation of synoviocytes of rats with KOA. Furthermore, upregulated miR-140-5p could inactivate the TLR4/Myd88/NF-κB signaling pathway in rats with KOA.

Conclusion: This study suggests that upregulated miR-140-5p could protect synovial injury by restraining inflammation reaction and apoptosis of synoviocytes in KOA rats via TLR4/Myd88/NF-κB signaling pathway inactivation.

Multi-pathway Protective Effects of MicroRNAs on Human Chondrocytes in an In Vitro Model of Osteoarthritis

Osteoarthritis (OA) is the most common degenerative joint disease. One of the main pathogenic factors of OA is thought to be inflammation. Other factors associated with OA are dysregulation of microRNAs, reduced autophagic activity, oxidative stress, and altered metabolism. microRNAs are small non-coding RNAs that are powerful regulators of gene expression. miR-140-5p is considered a cartilage-specific microRNA, is necessary for in vitro chondrogenesis, has anti-inflammatory properties, and is downregulated in osteoarthritic cartilage. Its passenger strand, miR-140-3p, is the most highly expressed microRNA in healthy cartilage and increases during in vitro chondrogenesis. miR-146a is a well-known anti-inflammatory microRNA. Several studies have illustrated its role in OA and autoimmune diseases. We show that, when human chondrocytes were transfected individually with miR-140-5p, miR-140-3p, or miR-146a prior to stimulation with interleukin-1 beta and tumor factor necrosis-alpha as an inflammatory model of OA, each of these microRNAs exhibited similar protective effects. Mass spectrometry analysis provided an insight to the altered proteome. All three microRNAs downregulated important inflammatory mediators. In addition, they affected different proteins belonging to the same biological processes, suggesting an overall inhibition of inflammation and oxidative stress, enhancement of autophagy, and restoration of other homeostatic cellular mechanisms, including metabolism.

Downregulation of microRNA-4324 promotes the EMT of esophageal squamous-cell carcinoma cells via upregulating FAK

Background: Esophageal squamous-cell carcinoma (ESCC) metastasis is the major cause of death of this severe and common malignancy. Focal adhesion kinase (FAK) is one of the key components of the focal adhesion complex, which is a multi-protein structure that controls cell adhesion, migration and invasion and regulates tumor metastasis. Purpose: To identify the roles and mechanisms of FAK in the regulation of Epithelial-to-mesenchymal transition (EMT) of ESCC cells. Methods: The expression of FAK and miR-4324 in both ESCC tissues and cells were evaluated by qRT-PCR and Immunohistochemistry analysis. Dual luciferase assays were performed for the confirmation of miR-4324's specific binding to 3'UTR of FAK mRNA. Besides, the trans-well assays and wound healing assays were employed to evaluate the effects of FAK /miR-4324 axis on the EMT regulation of ESCC cells. Furthermore, the relationship between miR-4374/FAK expression and clinical pathologic parameters & patient survival were also statistically analyzed. Results: In this study, we identified the upregulation of FAK and downregulation of miR-4324 in both ESCC cells and tissues. Overexpression of miR-4324 mimic, which significantly decreased cellular FAK levels, can impair the invasion potential and migration ability of ESCC cells. Besides, co-transfection of FAK can attenuate the function of miR-4324 mimic. Further experimental results demonstrated that miR-4324 mimic remarkably downregulated epithelial-to-mesenchymal transition (EMT) phenotype, which can also be effectively prevented by overexpressing FAK in ESCC cells. What's more, low miR-4324 and high FAK tissue levels have significant association with poor cell differentiation, tumor size and invasion depth as well as overall number of metastatic lymph nodes. Patients with high miR-4324 and low FAK levels in tumoral tissues lived longer than their counterparts, respectively. Conclusions: In conclusion, miR-4324/FAK axis could be a promising therapeutic target and potential prognostic biomarker for ESCC, which deserves further investigation in the clinic.

DNA methylation regulates miR-140-5p and miR-146a expression in osteoarthritis

AIMS

Previous studies have demonstrated that transcriptional silencing of miRNAs due to DNA hypermethylation is associated with different pathologies. It has also been reported that abnormal expression of miR-140-5p and miR-146a is linked to osteoarthritis (OA) progression. In this study, we investigated the role of DNA methylation on miR-140-5p and miR-146a expression in OA.

MAIN METHODS

miR-140-5p and miR-146a expression was investigated by qRT-PCR. The methylation status of miR-140 and miR-146a regulatory regions was analyzed using qMSP and bisulfite sequencing analysis. SMAD-3 and NF-kB binding to miR-140 and miR-146a regulatory regions was assessed by ChIP assay and knockdown experiments. OA-related genes' expression was evaluated in 5-AzadC, miRNAs inhibitor and 5-AzadC/miRNAs inhibitor-treated cells.

KEY FINDINGS

Hypermethylation of specific CpG sites in miR-140 and miR-146a regulatory regions was associated with downregulation of miR-140-5p and miR-146a in OA chondrocytes and synoviocytes, respectively. 5-AzadC-induced miR-140-5p and miR-146a upregulation was observed in OA chondrocytes and synoviocytes. Moreover, we found decreased binding affinity of SMAD-3 and NF-kB transcription factors on the hypermethylated miR-140-5p and miR-146a regulatory regions, respectively. Downregulation of MMP-13 and ADAMTS-5 in 5-AzadC-treated OA chondrocytes was prevented by miR-140-5p inhibitor transfection. Similarly, 5-AzadC-treated OA synoviocytes showed decreased expression of IRAK-1, IL1Β and IL-6, which was reversed following 5-AzadC-/miR-146a inhibitor treatment.

SIGNIFICANCE

Our results strongly suggest the impact of DNA methylation on miR-140-5p and miR-146a suppression in OA chondrocytes and synoviocytes, contributing to OA pathogenesis.

microRNA-138 induces cell survival and reduces WNT/β-catenin signaling of osteoarthritis chondrocytes through NEK2

Osteoarthritis (OA) is a degenerative joint disease characterized by joint pain, stiffness, and function degeneration with high incidence. Recent studies have been inspired based on the association between microRNAs (miRs) and therapeutic research of OA. Hence, the present study evaluates the effects of miR-138 on chondrocyte proliferation, differentiation, and apoptosis through the WNT/β-catenin signaling pathway in mice with OA by binding to NIMA-related kinase 2 (NEK2). Appropriate dataset was selected from the Gene Expression Omnibus database, and differentially expressed genes and potential miRNAs that could regulate NEK2 were explored. A mouse model of OA was established. The expressions of miR-138, NEK2, β-catenin, GSK3β, Bcl-2, Bcl-2-associated X protein (Bax), p53, MMP-13, Col2, and Aggrecan and the phosphorylation levels of β-catenin were determined by the reverse transcription quantitative polymerase chain reaction and Western blot analysis. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and flow cytometry were employed to detect cell proliferation and apoptosis, respectively. The potential functional role of NEK2 was revealed to be related to the WNT/β-catenin signaling pathway, and miR-138 was the putative regulator of NEK2. miR-138 expression was downregulated while expressions of NEK2 and β-catenin as well as the phosphorylation levels of β-catenin were upregulated in mice with OA. The chondrocytes treated with miR-138 mimic and siRNA-NEK2 exhibited reduced expressions of NEK2, β-catenin, MMP-13, Bax, and p53 and elevated expressions of Col2, Aggrecan, and Bcl-2 as well as phosphorylation levels of β-catenin along with enhanced chondrocytes' proliferation and suppressed cell apoptosis. Overexpression of miR-138 induces cell survival and reduces WNT/β-catenin signaling of OA chondrocytes through NEK2. © 2019 IUBMB Life, 71(9):1355-1366, 2019.

Interleukin-1 receptor antagonist protein (IL-1Ra) and miR-140 overexpression via pNNS-conjugated chitosan-mediated gene transfer enhances the repair of full-thickness cartilage defects in a rabbit model

Objectives

Previously, we reported the improved transfection efficiency of a plasmid DNA-chitosan (pDNA-CS) complex using a phosphorylatable nuclear localization signal-linked nucleic kinase substrate short peptide (pNNS) conjugated to chitosan (pNNS-CS). This study investigated the effects of pNNS-CS-mediated miR-140 and interleukin-1 receptor antagonist protein (IL-1Ra) gene transfection both in rabbit chondrocytes and a cartilage defect model.

Methods

The pBudCE4.1-miR-140, pBudCE4.1-IL-1Ra, and negative control pBudCE4.1 plasmids were constructed and combined with pNNS-CS to form pDNA/pNNS-CS complexes. These complexes were transfected into chondrocytes or injected into the knee joint cavity.

Results

High IL-1Ra and miR-140 expression levels were detected both in vitro and in vivo. In vitro, compared with the pBudCE4.1 group, the transgenic group presented with significantly increased chondrocyte proliferation and glycosaminoglycan (GAG) synthesis, as well as increased collagen type II alpha 1 chain (COL2A1), aggrecan (ACAN), and TIMP metallopeptidase inhibitor 1 (TIMP-1) levels. Nitric oxide (NO) synthesis was reduced, as were a disintegrin and metalloproteinase with thrombospondin type 1 motif 5 (ADAMTS-5) and matrix metalloproteinase (MMP)-13 levels. In vivo, the exogenous genes reduced the synovial fluid GAG and NO concentrations and the ADAMTS-5 and MMP-13 levels in cartilage. In contrast, COL2A1, ACAN, and TIMP-1 levels were increased, and the cartilage Mankin score was decreased in the transgenic group compared with the pBudCE4.1 group. Double gene combination produced greater efficacies than each single gene, both in vitro and in vivo.

Conclusion

This study suggests that pNNS-CS is a good candidate for treating cartilage defects via gene therapy, and that IL-1Ra in combination with miR-140 produces promising biological effects on cartilage defects.

Cite this article: R. Zhao, S. Wang, L. Jia, Q. Li, J. Qiao, X. Peng. Interleukin-1 receptor antagonist protein (IL-1Ra) and miR-140 overexpression via pNNS-conjugated chitosan-mediated gene transfer enhances the repair of full-thickness cartilage defects in a rabbit model. Bone Joint Res 2019;8:165–178. DOI: 10.1302/2046-3758.83.BJR-2018-0222.R1.

pNNS-Conjugated Chitosan Mediated IGF-1 and miR-140 Overexpression in Articular Chondrocytes Improves Cartilage Repair

The aim of the present study was to investigate the effects of phosphorylatable nucleus localization signal linked nucleic kinase substrate short peptide (^pNNS)-conjugated chitosan (^pNNS-CS) mediated miR-140 and IGF-1 in both rabbit chondrocytes and cartilage defects model. ^pNNS-CS was combined with pBudCE4.1-IGF-1, pBudCE4.1-miR-140, and negative control pBudCE4.1 to form pDNA/^pNNS-CS complexes. Then these complexes were transfected into chondrocytes or injected intra-articularly into the knee joints. High levels of IGF-1 and miR-140 expression were detected both in vitro and in vivo. Compared with pBudCE4.1 group, in vitro, the transgenic groups significantly promoted chondrocyte proliferation, increased glycosaminoglycan (GAG) synthesis, and ACAN, COL2A1, and TIMP-1 levels, and reduced the levels of nitric oxide (NO), MMP-13, and ADAMTS-5. In vivo, the exogenous genes enhanced COL2A1, ACAN, and TIMP-1 expression in cartilage and reduced cartilage Mankin score and the contents of NO, IL-1β, TNF-α, and GAG contents in synovial fluid of rabbits, MMP-13, ADAMTS-5, COL1A2, and COL10A1 levels in cartilage. Double gene combination showed better results than single gene. This study indicate that ^pNNS-CS is a better gene delivery vehicle in gene therapy for cartilage defects and that miR-140 combination IGF-1 transfection has better biologic effects on cartilage defects.

Kaempferol protects chondrogenic ATDC5 cells against inflammatory injury triggered by lipopolysaccharide through down-regulating miR-146a

Kaempferol is a kind of bioflavonoid exerts diverse pharmacological activities, including anti-apoptotic and anti-inflammatory activities. Kaempferol has been recognized as an effective agent for alleviating the clinical symptoms of osteoarthritis (OA). This study aimed to provide evidence that Kaempferol has potential in the management of OA. Lipopolysaccharide (LPS) stimulation induced a significant cell death and inflammatory injury in ATDC5 cells, as evidenced by the decreased cell viability, the induced apoptosis, the activated caspase-3, and the excessive production of IL-6, IL-8 and TNF-α. Precondition of cells with Kaempferol prevented apoptosis and the release of proinflammatory cytokines triggered by LPS. miR-146a was down-regulated by Kaempferol treatment, and Decorin was up-regulated by miR-146a overexpression. Consistently, both silence of miR-146a and Decorin exhibited Kaempferol-like effects towards ATDC5 cells stimulated by LPS. Moreover, Decorin silence activated PI3K/AKT/mTOR signaling pathway. In rat model of OA, the expression of miR-146a and Decorin in cartilage tissues was repressed by Kaempferol. Also, the activated PI3K/AKT/mTOR signaling pathway in OA animal model was enhanced by Kaempferol administration. These data suggested that Kaempferol exerted potential anti-OA effects through down-regulation of miR-146a, and thus repressing the expression of Decorin.

Potential Novel Prediction of TMJ-OA: MiR-140-5p Regulates Inflammation Through Smad/TGF-β Signaling

Temporomandibular joint osteoarthritis (TMJ-OA), mainly exhibit extracellular matrix loss and condylar cartilage degradation, is the most common chronic and degenerative maxillofacial osteoarthritis; however, no efficient therapy for TMJ-OA exists due to the poor understanding of its pathological progression. MicroRNA (miR)-140-5p is a novel non-coding microRNAs (miRNAs) that expressed in osteoarthritis specifically. To investigate the molecular mechanisms of miR-140-5p in TMJ-OA, primary mandibular condylar chondrocytes (MCCs) from C57BL/6N mice were treated with interleukins (IL)-1β or transfected with miR-140-5p mimics or inhibitors, respectively. The expression of matrix metallopeptidase (MMP)-13, miR-140-5p, nuclear factor (NF)-kB, Smad3 and transforming growth factor (TGF)-β3 were examined by western blotting or quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The interaction between the potential binding sequence of miR-140-5p and the 3'-untranslated region (3'UTR) of Smad3 mRNA was testified by dual-luciferase assay. Small Interfering RNA of Smad3 (Si-Smad3) was utilized to further identify the role of Smad3 mediated by miR-140-5p. The data showed MMP13, miR-140-5p and NF-kB increased significantly in response to IL-1β inflammatory response in MCCs, meanwhile, Smad3 and TGF-β3 reduced markedly. Moreover, transfection of miR-140-5p mimics significantly suppressed the expression of Smad3 and TGF-β3 in MCCs, while miR-140-5p inhibitors acted in a converse manner. As the luciferase reporter of Smad3 mRNA observed active interaction with miR-140-5p, Smad3 was identified as a direct target of miR-140-5p. Additionally, the expression of TGF-β3 was regulated upon the activation of Smad3. Together, these data suggested that miR-140-5p may play a role in regulating mandibular condylar cartilage homeostasis and potentially serve as a novel prognostic factor of TMJ-OA-like pathology.

Systematic Analysis of Transcriptomic Profile of Chondrocytes in Osteoarthritic Knee Using Next-Generation Sequencing and Bioinformatics

The phenotypic change of chondrocytes and the interplay between cartilage and subchondral bone in osteoarthritis (OA) has received much attention. Structural changes with nerve ingrowth and vascular penetration within OA cartilage may contribute to arthritic joint pain. The aim of this study was to identify differentially expressed genes and potential miRNA regulations in OA knee chondrocytes through next-generation sequencing and bioinformatics analysis. Results suggested the involvement of SMAD family member 3 (SMAD3) and Wnt family member 5A (WNT5A) in the growth of blood vessels and cell aggregation, representing features of cartilage damage in OA. Additionally, 26 dysregulated genes with potential miRNA⁻mRNA interactions were identified in OA knee chondrocytes. Myristoylated alanine rich protein kinase C substrate (MARCKS), epiregulin (EREG), leucine rich repeat containing 15 (LRRC15), and phosphodiesterase 3A (PDE3A) expression patterns were similar among related OA cartilage, subchondral bone and synovial tissue arrays in Gene Expression Omnibus database. The Ingenuity Pathway Analysis identified MARCKS to be associated with the outgrowth of neurite, and novel miRNA regulations were proposed to play critical roles in the pathogenesis of the altered OA knee joint microenvironment. The current findings suggest new perspectives in studying novel genes potentially contributing to arthritic joint pain in knee OA, which may assist in finding new targets for OA treatment.

Integrated miRNA and mRNA transcriptomes of spleen profiles between Yorkshire and Queshan black pigs

Disease causes large economic losses to the pig industry worldwidely, immunity plays an important role in the process of resistance to disease. In the present study, to elucidate the molecular mechanisms underlying different levels of disease resistance, we obtained the miRNA and mRNA expression profiles from the spleens of three groups of sows, including 180-day-old Queshan Black (Q-F), 3-day-old Yorkshire (Y-N) and 180-day-old Yorkshire (Y-F) pigs. The results showed that 85 miRNAs and 5093 genes were differentially expressed in Y-F vs Y-N, and 20 miRNAs and 1283 genes were differentially expressed in Q-F vs Y-F. Gene ontology analysis of these differentially expressed genes revealed their critical roles in response to immune response-related signaling pathways. To investigate the molecular mechanisms underlying immune diversity based on differentially expressed miRNAs and genes, the regulatory network between the node miRNAs and genes were established using Cytoscape. The results showed that the identified candidate miRNAs and genes were associated with immune response, and also indicated their potential roles in disease resistance variance between different pig breeds and stages. From the above, this research detected the key factors that were involved in disease resistance, and provide useful information for disease resistance breeding.

Comparison of molecular diagnosis with serum markers and synovial fluid analysis in patients with prosthetic joint infection

AIMS

The aim of this study was to compare the results of 16S/28S rRNA sequencing with the erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) level, and synovial fluid analysis in the diagnosis of prosthetic joint infection (PJI).

PATIENTS AND METHODS

Between September 2015 and August 2016, 214 consecutive patients were enrolled. In the study population, there were 25 patients with a PJI and 189 controls. Of the PJI patients, 14 (56%) were women, and the mean age at the time of diagnosis was 65 years (38 to 83). The ESR and CRP levels were measured, and synovial fluid specimens were collected prospectively. Synovial fluid was subjected to reverse transcription polymerase chain reaction (RT-PCR)/sequence analysis targeting the 16S/28S rRNA, and to conventional culture. Laboratory personnel who were blind to the clinical information performed all tests. The diagnosis of PJI was based on the criteria of the Musculoskeletal Infection Society.

RESULTS

A total of 25 patients had a confirmed PJI. In 20 cases of monomicrobial PJI, the PCR products could be perfectly matched with the 16S/28S rRNA genes specific for different species of bacteria provided by sequence analysis. Of the five polymicrobial cases of PJI, 16S/28S rRNA PCR sequence analysis failed to identify the concordant bacteria species. In the 189 control patients, there was one false-positive RT-PCR result. The sensitivity and specificity of the molecular diagnosis method were 100% (95% confidence interval (CI) 85.7 to 100) and 99.5% (95% CI 97.1 to 99.9), respectively, whereas the positive and negative predictive values of PCR were 96.1% (95% CI 79.6 to 99.9) and 100% (95% CI 98.1 to 100), respectively. The PCR results were significantly better than serological diagnostic methods (p = 0.004 and p = 0.010 for ESR and CRP, respectively), the synovial fluid white blood cell (WBC) count (p = 0.036), and percentage of polymorphonuclear cells (PMN%) (p = 0.014).

CONCLUSION

Stepwise RT-PCR and sequence analysis of the 16S/28S rRNA carried out under stringent laboratory conditions achieved highly sensitive and specific results for the differentiation between aseptic and septic joints undergoing arthroplasty. Sequence analysis successfully identified bacterial strains in monomicrobial infections but failed to identify molecular targets in polymicrobial infections. Further refinement of the protocols to identify the bacteria in polymicrobial infections is needed. Cite this article: Bone Joint J 2018;100-B:1345-51.

The complex landscape of microRNAs in articular cartilage: biology, pathology, and therapeutic targets

The disabling degenerative disease osteoarthritis (OA) is prevalent among the global population. Articular cartilage degeneration is a central feature of OA; therefore, a better understanding of the mechanisms that maintain cartilage homeostasis is vital for developing effective therapeutic interventions. MicroRNAs (miRs) modulate cell signaling pathways and various processes in articular cartilage via posttranscriptional repression of target genes. As dysregulated miRs frequently alter the homeostasis of articular cartilage, modulating select miRs presents a potential therapeutic opportunity for OA. Here, we review key miRs that have been shown to modulate cartilage-protective or -destructive mechanisms and signaling pathways. Additionally, we use an integrative computational biology approach to provide insight into predicted miR gene targets that may contribute to OA pathogenesis, and highlight the complexity of miR signaling in OA by generating both unique and overlapping gene targets of miRs that mediate protective or destructive effects. Early OA detection would enable effective prevention; thus, miRs are being explored as diagnostic biomarkers. We discuss these ongoing efforts and the applicability of miR mimics and antisense inhibitors as potential OA therapeutics.

Obesity, osteoarthritis and genetic risk: The rs182052 polymorphism in the ADIPOQ gene is potentially associated with risk of knee osteoarthritis

Objectives

Given the function of adiponectin (ADIPOQ) on the inflammatory condition of obesity and osteoarthritis (OA), we hypothesized that the ADIPOQ gene might be a candidate gene for a marker of susceptibility to OA.

Methods

We systematically screened three tagging polymorphisms (rs182052, rs2082940 and rs6773957) in the ADIPOQ gene, and evaluated the association between the genetic variants and OA risk in a case-controlled study that included 196 OA patients and 442 controls in a northern Chinese population. Genotyping was performed using the Sequenom MassARRAY iPLEX platform.

Results

The single nucleotide polymorphism (SNP) rs182052 was found to be potentially associated with knee OA risk (additive model: odds ratio = 1.38; 95% confidence interval 1.07 to 1.76; p = 0.012). Furthermore, a non-significant association was observed for rs182052 and body mass index with regard to OA risk in interaction analyses (p = 0.063). Similarly, no significant interaction was detected for rs182052 and age with regard to OA risk (p = 0.614).

Conclusion

These findings suggest that the SNP rs182052 in the ADIPOQ gene may potentially modify individual susceptibility to knee OA in the Chinese population. Further studies are warranted to investigate our findings in more depth.

Cite this article: L. Jiang, X. Zhu, J. Rong, B. Xing, S. Wang, A. Liu, M. Chu, G. Huang. Obesity, osteoarthritis and genetic risk: The rs182052 polymorphism in the ADIPOQ gene is potentially associated with risk of knee osteoarthritis. Bone Joint Res 2018;7:494–500. DOI: 10.1302/2046-3758.77.BJR-2017-0274.R1.

Comparison of pain behaviour and osteoarthritis progression between anterior cruciate ligament transection and osteochondral injury in rat models

Objectives

In this study, we compared the pain behaviour and osteoarthritis (OA) progression between anterior cruciate ligament transection (ACLT) and osteochondral injury in surgically-induced OA rat models.

Methods

OA was induced in the knee joints of male Wistar rats using transection of the ACL or induction of osteochondral injury. Changes in the percentage of high limb weight distribution (%HLWD) on the operated hind limb were used to determine the pain behaviour in these models. The development of OA was assessed and compared using a histological evaluation based on the Osteoarthritis Research Society International (OARSI) cartilage OA histopathology score.

Results

Both models showed an increase in joint pain as indicated by a significant (p < 0.05) decrease in the values of %HLWD at one week post-surgery. In the osteochondral injury model, the %HLWD returned to normal within three weeks, while in the ACLT model, a significant decrease in the %HLWD was persistent over an eight-week period. In addition, OA progression was more advanced in the ACLT model than in the osteochondral injury model. Furthermore, the ACLT model exhibited a higher mean OA score than that of the osteochondral injury model at 12 weeks.

Conclusion

The development of pain patterns in the ACLT and osteochondral injury models is different in that the OA progression was significant in the ACLT model. Although both can be used as models for a post-traumatic injury of the knee, the selection of appropriate models for OA in preclinical studies should be specified and relevant to the clinical scenario.

Cite this article: T. Tawonsawatruk, O. Sriwatananukulkit, W. Himakhun, W. Hemstapat. Comparison of pain behaviour and osteoarthritis progression between anterior cruciate ligament transection and osteochondral injury in rat models. Bone Joint Res 2018;7:244–251. DOI: 10.1302/2046-3758.73.BJR-2017-0121.R2.