LncRNA SNHG7 alleviates IL-1β-induced osteoarthritis by inhibiting miR-214-5p-mediated PPARGC1B signaling pathways

LncRNA SNHG7 inhibits apoptosis and proliferation of osteoarthritis cells induced by IL-β through sponging miR-146b

PURPOSE

We probed the roles of SNHG7, miR-146b, PCBP1, and IL-β in the development of osteoarthritis (OA).

MATERIALS AND METHODS

OA models were established using anterior cruciate ligaments, and chondrocytes were obtained from mouse cartilage tissue. Cells were treated with 10 ng/ml Il-1β. RT-qPCR was used to detect the expression of SNHG7, miR-146b, PCBP1, and IL-β in tissues and cells. Safranin-O/Fast Green staining was performed to analyze the cartilage damage in each group of mice.

RESULTS

SNHG7 and PCBP1 expressions were down-regulated, and miR-146b expression was up-regulated in OA tissue and IL-1β-treated chondrocytes compared to normal cartilage tissue and chondrocytes. Forced SNHG7 expression improved cartilage structure, enhanced proliferative viability of chondrocytes, and inhibited apoptosis and IL-1β release in IL-1β-treated chondrocytes in OA mice. In contrast, miR-146b upregulation decreased proliferative viability and promoted apoptosis and IL-1β release in chondrocytes. Rescue assays showed that miR-146b attenuated the protective effects of SNHG7 on apoptosis and inflammation in IL-1β-treated chondrocytes, and activation of PCBP1 expression significantly inhibited the cytotoxic effects of miR-146b. Mechanistically, SNHG7 acted as a competitive endogenous RNA by targeting miR-146b to promote the expression of PCBP1.

CONCLUSIONS

This study confirms that SNHG7 inhibits IL-1β-mediated inflammatory responses in chondrocytes via the miR-146b/PCBP1 axis, thereby suppressing IL-1β-induced OA.

A review of molecular interplay between inflammation and cancer: The role of lncRNAs in pathogenesis and therapeutic potential

The inflammatory microenvironment (IME) has been demonstrated to facilitate the initiation and progression of tumors throughout the inflammatory process. Simultaneously, cancer can initiate or intensify the inflammatory response, thereby promoting tumor progression. This review examines the dual role of long non-coding RNAs (lncRNAs) in the interplay between inflammation and cancer. LncRNA modulate inflammation-induced cancer by influencing the activation of signaling pathways (NF-κB, Wnt/β-catenin, mTOR, etc), microRNA (miRNA) sponging, protein interactions, interactions with immune cells, and encoding short peptides. In contrast, lncRNAs also impact cancer-induced inflammatory processes by regulating cytokine expression, mediating tumor-derived extracellular vesicles (EVs), modulating intracellular reactive oxygen species (ROS) levels, and facilitating metabolic reprogramming. Furthermore, the therapeutic potential of lncRNA and the challenges of clinical translation were explicitly discussed as well. Overall, this review aims to provide a comprehensive and systematic resource for future researchers investigating the impact of lncRNAs on inflammation and cancer.

LINC00942 Alleviates NaAsO2-induced Apoptosis by Promoting GSH Synthesis Through Targeting miR-214-5p

The mechanism of arsenic-induced liver toxicity is not fully understood. This study aimed to investigate the role of LINC00942 in arsenic-induced hepatotoxicity by regulating miR-214-5p. As the exposure dose of NaAsO2 gradually increases, cell viability, intracellular GSH content, ΔΨm, and the protein levels of GCLC and GCLM were reduced significantly. Apoptosis rate, ROS, and expression of apoptosis-related and NF-κB pathway proteins increased. The expression of LINC00942 was increased, while the expression of miR-214-5p was decreased. After suppressing LINC00942 levels, NaAsO2 exposure further decreased cell viability, intracellular GSH content, ΔΨm, GCLC protein, and miR-214-5p expression. The apoptosis rate, ROS, and apoptosis-related and NF-κB pathway proteins further increased. miR-214-5p is targeted and negatively regulated by LINC00942. After miR-214-5p was overexpressed, NaAsO2 further decreased cell viability, intracellular GSH content, ΔΨm, and GCLC protein expression compared to NaAsO2 exposure. The apoptosis rate, ROS, apoptosis-related and NF-κB pathway proteins p65, and IKKβ were higher than those exposed to NaAsO2. LINC00942 inhibitor along with miR-214-5p inhibitor combined with NaAsO2 treatment resulted in increased cell viability, GSH, Bcl-2, and GCLC protein expression and decreased apoptosis rate, apoptosis related, p65, IKKβ protein, and ΔΨm, as compared to the combined NaAsO2 and si LINC00942 group. NaAsO2 exposure induces oxidative damage and apoptosis in LX-2 cells by activating NF-κB and inhibiting GSH synthesis. During this process, the expression level of LINC00942 increases, targeting to reduce the level of miR-214-5p, then weakening the effect of NaAsO2 on NF-κB, thereby alleviating cellular oxidative damage and playing a protective role.

LncRNA NKILA attenuates the progression of osteoarthritis through the targeted inhibition of the NF-κB pathway

BACKGROUND

Interleukin-1β (IL-1β) plays a crucial role in cartilage degeneration by inducing inflammatory cascades in chondrocytes, impairing their normal biological functions. Long non-coding RNA NKILA (lncRNA NKILA) has been implicated in osteoarthritis (OA), but its specific molecular mechanisms remain unclear. This study aims to elucidate the function and molecular regulatory mechanism of lncRNA NKILA in articular chondrocytes under IL-1β stimulation.

METHODS

Primary human articular chondrocytes were cultured to investigate the effects of IL-1β on chondrocyte proliferation, apoptosis, and extracellular matrix metabolism. We employed Reverse Transcription Quantitative Polymerase Chain Reaction (RT-qPCR), western blot, flow cytometry, immunofluorescence, and nuclear mass separation assays to explore the interaction between lncRNA NKILA and the NFκB signaling pathway. Additionally, animal experiments were conducted to evaluate the therapeutic potential of modulating lncRNA NKILA expression in vivo.

RESULTS

IL-1β treatment led to decreased chondrocyte proliferation and increased apoptosis. Our study demonstrated that IL-1β downregulates lncRNA NKILA, which weakens its inhibitory effect on the NFκB (Nuclear Factor Kappa B) signaling pathway. This downregulation results in increased NFκB activity and exacerbates chondrocyte degeneration. Notably, the upregulation of lncRNA NKILA significantly alleviated OA symptoms, indicating that NKILA could be a promising therapeutic target.

CONCLUSION

IL-1β reduces lncRNA NKILA expression, weakening its inhibition of NFκB signaling and promoting articular chondrocyte degeneration. Enhancing lncRNA NKILA expression offers a promising approach to mitigating OA, suggesting that NKILA could serve as a potential therapeutic target for OA treatment.

CRNDE alleviates IL-1β-induced chondrocyte damage by modulating miR-31/NF-κB pathway

BACKGROUND

The long non-coding RNA CRNDE (CRNDE) has been identified as a lncRNA associated with osteoarthritis (OA), playing a role the age-related degeneration of articular cartilage. However, the precise mechanism by which CRNDE affects the physiological functions of OA chondrocytes remains unclear.

METHODS

To simulate the inflammatory conditions observed in OA, interleukin (IL)-1β-stimulated chondrocyte C-28/I2 cells were utilized. The expression levels of CRNDE and miR-31 were assessed using reverse transcription-polymerase chain reaction (RT-PCR). Chondrocyte viability and apoptosis were evaluated through CCK-8 assay and flow cytometry, respectively. The levels of IL-6, IL-1β and Tumor necrosis factor (TNF-α) were determined using enzyme-linked immunosorbent assay (ELISA). mRNA expression levels of MMP-13, Aggrecan and COL2A1 were detected by quantitative RT-PCR. Western blot analysis was performed to evaluate the protein levels of factors related to cartilage matrix degradation, including p-p65, p65 and p-IκBα of the NF-κB pathway.

RESULTS

CRNDE expression was downregulated in both OA cartilage tissues and IL-1β-stimulated chondrocytes. Overexpression of CRNDE mitigated IL-1β-stimulated chondrocytes apoptosis, inflammatory responses, and cartilage matrix degradation. Compared with healthy controls, OA tissues exhibited reduced expression of miR-31, which was negatively correlated with the expression of CRNDE. Additionally, overexpression of miR-31 partially reversed the inhibitory effects of CRNDE on apoptosis, inflammation, cartilage matrix degradation, and the inactivation of Nuclear factor (NF)-κB pathway induced by IL-1β stimulation. Moreover, silencing of CRNDE exacerbated IL-1β-induced chondrocytes damage, which was aliviated by the NF-κB pathway inhibitor, Bay 11-7082.

CONCLUSION

CRNDE alleviated IL-1β-induced injuries in OA chondrocytes by suppressing the miR-31-mediated NF-κB signaling pathway.

Exosomes-Shuttled lncRNA SNHG7 by Bone Marrow Mesenchymal Stem Cells Alleviates Osteoarthritis Through Targeting miR-485-5p/FSP1 Axis-Mediated Chondrocytes Ferroptosis and Inflammation

BACKGROUND

Osteoarthritis (OA), a degenerative joint disorder, is a major reason of disability in adults. Accumulating evidences have proved that bone marrow mesenchymal stem cells (BMSCs)-carried exosomes play a significant therapeutic effect on OA. However, the precise regulatory network remains unknown.

METHODS

OA and normal cartilage samples were acquired from patients, and chondrocytes were exposed to IL-1β to conduct a cellular OA model. Exosomes prepared from BMSCs were identified using nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). Cell viability was determined with CCK-8 assay. Inflammatory injury was assessed by LDH and inflammatory factors (TNF-α and IL-6) using corresponding ELISA kits, respectively. Ferroptosis was evaluated by GSH, MDA and iron levels using corresponding kits, and ROS level with DCFH-DA. The expressions of genes/proteins were determined with RT-qPCR/western bolt. RNA immunoprecipitation and luciferase activity assay were conducted for testing the interactions of small nucleolar RNA host gene 7 (SNHG7)/ferroptosis suppressor protein 1 (FSP1) and miR-485-5p.

RESULTS

The expressions of SNHG7 and FSP1 were both reduced in IL-1β-induced chondrocytes and OA cartilage tissues, and there was a positive correlation between them in clinical level. Moreover, SNHG7 was enriched in BMSCs-derived exosomes (BMSCs-Exos) and could be internalized by chondrocytes. Functional analysis illustrated that BMSCs-Exos administration repressed inflammatory injury, oxidative stress and ferroptosis in IL-1β-induced chondrocytes, while these changes were reinforced when SNHG7 was overexpressed in BMSCs-Exos. Notably, FSP1 silencing in chondrocytes abolished the beneficial effects mediated by exosomal SNHG7.

CONCLUSIONS

Exosomal SNHG7 released from BMSCs inhibited inflammation and ferroptosis in IL-1β-induced chondrocytes through miR-485-5p/FSP1 axis. This work suggested that BMSCs-derived exosomal SNHG7 would be a prospective target for OA treatment.

Long Non-coding RNA SNHG7 Suppresses Inflammation and Apoptosis of Chondrocytes Through Inactivating of p38 MAPK Signaling Pathway in Osteoarthritis

This study aims to explore the molecular mechanism of LncRNA SNHG7 in Osteoarthritis (OA). Cartilage tissues of OA patients or patients with trauma or amputation were collected. Compared to normal cartilage tissues, SNHG7 was downregulated while miR-324-3p was upregulated in cartilage tissues of OA patients. IL-1β was used to induce damage to chondrocytes and treatment with IL-1β reduced SNHG7 expression in OA chondrocytes. In IL-1β-treated OA chondrocytes, SNHG7 overexpression reduced the levels of TNF-α and IL-6, inhibited cell apoptosis, and increased cell viability. Additionally, the luciferase reporter assay proved that SNHG7 upregulated dual-specificity phosphatase 1 (DUSP1) by sponging miR-324-3p, thereby inactivating the p38 MAPK signaling pathway by regulating the miR-324-3p/DUSP1 axis. Anisomycin (a p38 MAPK activator) enhanced OA chondrocytes inflammation, promoted cell apoptosis, and reduced cell viability; however, this was reversed by SNHG7 overexpression. This study demonstrates that the SNHG7/miR-324-3p/DUSP1 axis suppresses OA chondrocytes inflammation and apoptosis by inhibiting the p38 MAPK signaling pathway. Thus, this study indicates that SNHG7 is a novel target for OA treatment.

Pyroptosis: A spoiler of peaceful coexistence between cells in degenerative bone and joint diseases

BACKGROUND

As people age, degenerative bone and joint diseases (DBJDs) become more prevalent. When middle-aged and elderly people are diagnosed with one or more disorders such as osteoporosis (OP), osteoarthritis (OA), and intervertebral disc degeneration (IVDD), it often signals the onset of prolonged pain and reduced functionality. Chronic inflammation has been identified as the underlying cause of various degenerative diseases, including DBJDs. Recently, excessive activation of pyroptosis, a form of programed cell death (PCD) mediated by inflammasomes, has emerged as a primary driver of harmful chronic inflammation. Consequently, pyroptosis has become a potential target for preventing and treating DBJDs.

AIM OF REVIEW

This review explored the physiological and pathological roles of the pyroptosis pathway in bone and joint development and its relation to DBJDs. Meanwhile, it elaborated the molecular mechanisms of pyroptosis within individual cell types in the bone marrow and joints, as well as the interplay among different cell types in the context of DBJDs. Furthermore, this review presented the latest compelling evidence supporting the idea of regulating the pyroptosis pathway for DBJDs treatment, and discussed the potential, limitations, and challenges of various therapeutic strategies involving pyroptosis regulation.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In summary, an interesting identity for the unregulated pyroptosis pathway in the context of DBJDs was proposed in this review, which was undertaken as a spoiler of peaceful coexistence between cells in a degenerative environment. Over the extended course of DBJDs, pyroptosis pathway perpetuated its activity through crosstalk among pyroptosis cascades in different cell types, thus exacerbating the inflammatory environment throughout the entire bone marrow and joint degeneration environment. Correspondingly, pyroptosis regulation therapy emerged as a promising option for clinical treatment of DBJDs.

Mechanisms of NLRP3 inflammasome in rheumatoid arthritis and osteoarthritis and the effects of traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

It has been widely reported that various anti-rheumatic traditional Chinese medicines (TCMs) ameliorate rheumatoid arthritis (RA) and osteoarthritis (OA) through regulating the abnormal production, assembly, and activation of the NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome. These TCMs include monomers isolated from Chinese herbs, extracts of Chinese herbs, and Chinese medical formulae with a lengthy application history.

AIM OF THE STUDY

This review aimed to summarize and analyze the published articles about the NLRP3 inflammasome and its role in the pathogenesis of RA and OA. We also reviewed existing knowledge on the therapeutic mechanism of TCMs in RA and OA via the regulation of the NLRP3 inflammasome.

MATERIALS AND METHODS

We searched for relevant articles with the keywords "NLRP3 inflammasome", "traditional Chinese medicine," "Chinese herbal drugs," "rheumatoid arthritis," and "osteoarthritis." The information retrieval was conducted in medical Chinese and English databases from the date of construction to April 19, 2023, including PubMed, MEDLINE, Web of Science, Scopus, Ovid, China National Knowledge Infrastructure (CNKI), Chinese Biomedicine Literature Database (CBM), Chinese Science and Technology Periodicals Database (VIP), and China Online Journals (COJ).

RESULTS

According to retrieval results, 35 TCMs have been demonstrated to relieve RA by targeting the NLRP3 inflammasome, including six traditional Chinese prescriptions, seven extracts of Chinese herbs, and 22 monomers extracted from traditional Chinese herbs and formulae. Additionally, 23 TCMs have shown anti-OA effects with abilities to modulate the NLRP3 inflammasome, including five traditional Chinese prescriptions, one extract of Chinese herbs, and 17 monomers from Chinese herbs.

CONCLUSIONS

We summarized mechanism research about the pivotal roles of the NLRP3 inflammasome in the pathogenesis of RA and OA. Moreover, a review of TCMs with targets of the NLRP3 inflammasome in RA and OA treatment was also conducted. Our work is conducive to a better application of TCMs in complementary and alternative therapies in RA and OA.

Research of the analgesic effects and central nervous system impact of electroacupuncture therapy in rats with knee osteoarthritis

It aimed to observe the effects of TongDu TiaoShen (TDTS) electroacupuncture (EA) on the analgesia and central system of knee osteoarthritis (KOA) rats and explore its mechanism. SD rats were rolled into the blank group, model group (KOA), control group (duloxetine 500 mg/kg/d, Ctrl), conventional EA group, and TDTS-EA group. Radiometric pain measurements and the Lequesne MG scale were used to evaluate the behavioral performance of the rats. Dopamine (DA), norepinephrine (NE), 5-hydroxytryptamine (5-HT), β-endorphin (β-EP), and leucine-enkephalin (L-ENK) were detected in the midbrain and spinal cord of lumbar enlargement. Interleukin (IL)-1β protein expression was detected by Western blot. The incubation period of thermal pain and foot contraction was decreased in the KOA group versus blank group, the Lequesne MG score was increased, DA, NE, 5-HT, β-EP, and L-ENK in the midbrain and spinal cord were increased, and synovial tissue IL-1β protein expression was increased (P < 0.05). EA group and TDTS-EA group had an increased incubation period of thermal pain contraction, decreased Lequesne MG score, decreased DA, NE, etc. In the midbrain, increased 5-HT and NE in the spinal cord, and decreased IL-1β in the synovial tissue versus KOA group (P < 0.05). The Lequesne MG score and midbrain DA, NE, 5-HT, β-EP, and synovial tissue IL-1β expression were decreased in TDTS-EA group versus EA group (P < 0.05). EA can effectively improve the behavioral score of KOA and participate in central analgesia by regulating central DA, NE, 5-HT, β-EP, and L-ENK.

HLA-DQA1*05 and upstream variants of PPARGC1B are associated with infliximab persistence in Japanese Crohn's disease patients

Recently, the HLA-DQA1*05 (rs2097432) genetic variation has been reported to be linked to early infliximab (IFX) treatment failure in the Caucasian Crohn's disease (CD) population, but that evidence is scarce in the Asian population. This study aimed to investigate the relationship between rs2097432 and the cumulative discontinuation-free time of IFX (IFX persistence) in 189 Japanese biologics-naive CD patients. We also performed a genome-wide association study (GWAS) to discover novel genetic predictors for IFX persistence. The C allele of rs2097432 significantly increased the risk of early discontinuation of IFX [Hazard ratio (HR) = 2.23 and P-value = 0.026]. In GWAS, one locus tagged by rs73277969, located upstream of PPARGC1B which attenuates macrophage-mediated inflammation, reached genome-wide significance (HR = 6.04 and P-value = 7.93E-9). Pathway analysis suggested association of signaling by PDGF and FCGR activation signaling with IFX persistence (P-value = 8.56E-5 and 5.80E-4, respectively).

The emerging role of lncRNAs in osteoarthritis development and potential therapy

Osteoarthritis impairs the functions of various joints, such as knees, hips, hands and spine, which causes pain, swelling, stiffness and reduced mobility in joints. Multiple factors, including age, joint injuries, obesity, and mechanical stress, could contribute to osteoarthritis development and progression. Evidence has demonstrated that genetics and epigenetics play a critical role in osteoarthritis initiation and progression. Noncoding RNAs (ncRNAs) have been revealed to participate in osteoarthritis development. In this review, we describe the pivotal functions and molecular mechanisms of numerous lncRNAs in osteoarthritis progression. We mention that long noncoding RNAs (lncRNAs) could be biomarkers for osteoarthritis diagnosis, prognosis and therapeutic targets. Moreover, we highlight the several compounds that alleviate osteoarthritis progression in part via targeting lncRNAs. Furthermore, we provide the future perspectives regarding the potential application of lncRNAs in diagnosis, treatment and prognosis of osteoarthritis.

Downregulation of lncRNA NEAT1 interacts with miR-374b-5p/PGAP1 axis to aggravate the development of osteoarthritis

BACKGROUND

Osteoarthritis (OA), characterized by inflammation and articular cartilage degradation, is a prevalent arthritis among geriatric population. This paper was to scrutinize the novel mechanism of long noncoding RNA (lncRNA) NEAT1 in OA etiology.

METHODS

A total of 10 OA patients and 10 normal individuals was included in this study. Cell model of OA was built in human normal chondrocytes induced by lipopolysaccharide (LPS). An OA Wistar rat model was established through intra-articular injection of L-cysteine and papain mixtures (proportion at 1:2) into the right knee. Quantitative reverse transcription-polymerase chain reaction was employed to ascertain the expression levels of NEAT1, microRNA (miR)-374b-5p and post-GPI attachment to protein 1 (PGAP1), while dual-luciferase reporter experiments were used for the validation of target relationship among them. Cell cycle and apoptosis were calculated by flow cytometry analysis. CCK-8 assay was done to evaluate the proliferative potentials of chondrocytes. The levels of cell cycle-related proteins (Cyclin A1, Cyclin B1 and Cyclin D2) and pro-apoptotic proteins (Caspase3 and Caspase9) were measured by western blotting. Tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β) and IL-6 levels were determined via ELISA. Hematoxylin & eosin (HE) Staining was used for pathological examination in OA rats.

RESULTS

Pronounced downregulation of NEAT1 and PGAP1 and high amounts of miR-374b-5p were identified in OA patients, LPS-induced chondrocytes and OA rats. NEAT1 targeted miR-374b-5p to control PGAP1 expression. Loss of NEAT1 or upregulation of miR-374b-5p dramatically accelerated apoptosis, led to the G1/S arrest and promoted the secretion of inflammatory cytokines in LPS-induced chondrocytes, while ectopic expression of PGAP1 exhibited the opposite influences on chondrocytes. Additionally, we further indicated that upregulation of miR-374b-5p attenuated the effects of PGAP1 overexpression on LPS-induced chondrocytes.

CONCLUSIONS

Reduced NEAT1 induces the development of OA via miR-374b-5p/PGAP1 pathway. This suggests that the regulatory axis NEAT1/miR-374b-5p/PGAP1 is a novel and prospective target for OA treatment.

Construction of an immune-related lncRNA-miRNA-mRNA regulatory network in radiation-induced esophageal injury in rats

Radiation-induced esophageal injury (RIEI) is an adverse reaction of radiation therapy in patients with esophageal cancer, lung cancer and other malignant tumors. Competitive endogenous RNA (ceRNA) network is known to play a significant role in the onset and progression of many diseases, but the exact mechanism of ceRNA in RIEI has not been fully elucidated. In this study, rat esophaguses were obtained after conducting irradiation under different doses (0 Gy, 25 Gy, 35 Gy). Total RNA was extracted and mRNA, lncRNA, circRNA, and miRNA sequencing was performed. Multiple dose-dependent differentially expressed RNAs (dd-DERs), including 870 lncRNAs, 82 miRNAs, 2478 mRNAs, were obtained through the integration of differential expression analysis and dose-dependent screening (35 Gy ≥ 25 Gy > 0 Gy, or 35 Gy ≤ 25 Gy < 0 Gy). Co-expression analysis and prediction of the binding site in dd-DER were conducted and 27 lncRNAs, 20 miRNAs, and 168 mRNAs were selected to construct a ceRNA network. As the immune microenvironment is crucial for RIEI progression, we constructed an immune-related ceRNA network consisting of 11 lncRNAs, 9 miRNAs, and 9 mRNAs. The expression levels of these immune-related RNAs were verified by RT-qPCR. Immune infiltration analysis showed that the RNAs in the immune-related ceRNA network were mainly associated with the proportion of monocytes, M2 macrophages, activated NK cells, and activated CD4+ memory T cells. Drug sensitivity analysis was conducted based on the expression levels of mRNAs in the immune-related ceRNA network, and small molecule drugs with preventive and therapeutic effects on RIEI were identified. In summary, an immune-related ceRNA network associated with RIEI progression was constructed in this study. The findings provide useful information on new potential targets for the prevention and treatment of RIEI.

Genkwanin suppresses mitochondrial dysfunction to alleviate IL-1β-elicited inflammation, apoptosis, and degradation of extracellular matrix in chondrocytes through upregulating DUSP1

Osteoarthritis (OA) is a form of chronic degenerative disease contributing to elevated disability rate among the elderly. Genkwanin is an active component extracted from Daphne genkwa possessing pharmacologic effects. Here, this study is designed to expound the specific role of genkwanin in OA and elaborate the probable downstream mechanism. First, the viability of chondrocytes in the presence or absence of interleukin-1 beta (IL-1β) treatment was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay was used to assess cell apoptosis. Inflammatory response was estimated through enzyme-linked immunosorbent assay and Western blot. In addition, immunofluorescence staining and Western blot were utilized to measure the expression of extracellular matrix (ECM)-associated proteins. Dual-specificity protein phosphatase-1 (DUSP1) expression was tested by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot. Following DUSP1 elevation in genkwanin-treated chondrocytes exposed to IL-1β, inflammatory response and ECM-associated factors were evaluated as forementioned. In addition, 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbocyanine iodide staining was to assess the mitochondrial membrane potential. Adenosine triphosphate (ATP) level was examined with ATP assay kit, and RT-qPCR was used to test mitochondrial DNA expression. Results indicated that genkwanin administration enhanced the viability while ameliorated the apoptosis, inflammatory response, and ECM degradation in IL-1β-induced chondrocytes. Besides, genkwanin treatment fortified DUSP1 expression in IL-1β-exposed chondrocytes. DUSP1 interference further offsets the impacts of genkwanin on the inflammation, ECM degradation, and mitochondrial dysfunction in IL-1β-challenged chondrocytes. In short, genkwanin enhanced DUSP1 expression to mitigate mitochondrial dysfunction, thus ameliorating IL-1β-elicited inflammation, apoptosis, and degradation of ECM in chondrocytes.

The role of apoptosis in the pathogenesis of osteoarthritis

PURPOSE

Apoptosis is an important physiological process, making a great difference to development and tissue homeostasis. Osteoarthritis (OA) is a chronic joint disease characterized by degeneration and destruction of articular cartilage and bone hyperplasia. This purpose of this study is to provide an updated review of the role of apoptosis in the pathogenesis of osteoarthritis.

METHODS

A comprehensive review of the literature on osteoarthritis and apoptosis was performed, which mainly focused on the regulatory factors and signaling pathways associated with chondrocyte apoptosis in osteoarthritis and other pathogenic mechanisms involved in chondrocyte apoptosis.

RESULTS

Inflammatory mediators such as reactive oxygen species (ROS), nitric oxide (NO), IL-1β, tumor necrosis factor-α (TNF-α), and Fas are closely related to chondrocyte apoptosis. NF-κB signaling pathway, Wnt signaling pathway, and Notch signaling pathway activate proteins and gene targets that promote or inhibit the progression of osteoarthritis disease, including chondrocyte apoptosis and ECM degradation. Long non-coding RNAs (LncRNAs) and microRNAs (microRNAs) have gradually replaced single and localized research methods and become the main research approaches. In addition, the relationship between cellular senescence, autophagy, and apoptosis was also briefly explained.

CONCLUSION

This review offers a better molecular delineation of apoptotic processes that may help in designing new therapeutic options for OA treatment.

Identification of Inflammatory Gene in the Congenital Heart Surgery Patients following Cardiopulmonary Bypass via the Way of WGCNA and Machine Learning Algorithms

Performing cardiopulmonary bypass (CPB) to reduce ischemic injury during surgery is a common approach to cardiac surgery. However, this procedure can lead to systemic inflammation and multiorgan dysfunction. Therefore, elucidating the molecular mechanisms of CPB-induced inflammatory cytokine release is essential as a critical first step in identifying new targets for therapeutic intervention. The GSE143780 dataset which is mRNA sequencing from total circulating leukocytes of the neonatorum was downloaded from the Gene Expression Omnibus (GEO) database. A total of 21 key module genes were obtained by analyzing the intersection of differentially expressed gene (DEG) and gene coexpression network analysis (WGCNA), and then, 4 genes (TRAF3IP2-AS1, PPARGC1B, CD4, and PDLIM5) were further confirmed after the least absolute shrinkage and selection operator (LASSO) and support vector machine recursive feature elimination (SVM-RFE) screening and were used as hub genes for CPB-induced inflammatory cytokine release in patients with congenital heart defects. The enrichment analysis revealed 21 key module genes mainly related to the functions of developmental cell growth, regulation of monocyte differentiation, regulation of myeloid leukocyte differentiation, ERK1 and ERK2 cascade, volume-sensitive anion channel activity, and estrogen receptor binding. The result of gene set enrichment analysis (GSEA) showed that the hub genes were related to different physiological functions of cells. The ceRNA network established for hub genes includes 3 hub genes (PPARGC1B, CD4, and PDLIM5), 55 lncRNAs, and 34 miRNAs. In addition, 4 hub genes have 215 potential therapeutic agents. Finally, expression validation of the four hub genes revealed that they were all significantly low expressed in the surgical samples than before.

Advances in Research on the Regulatory Roles of lncRNAs in Osteoarthritic Cartilage

Osteoarthritis (OA) is the most common degenerative bone and joint disease that can lead to disability and severely affect the quality of life of patients. However, its etiology and pathogenesis remain unclear. It is currently believed that articular cartilage lesions are an important marker of the onset and development of osteoarthritis. Long noncoding RNAs (lncRNAs) are a class of multifunctional regulatory RNAs that are involved in various physiological functions. There are many differentially expressed lncRNAs between osteoarthritic and normal cartilage tissues that play multiple roles in the pathogenesis of OA. Here, we reviewed lncRNAs that have been reported to play regulatory roles in the pathological changes associated with osteoarthritic cartilage and their potential as biomarkers and a therapeutic target in OA to further elucidate the pathogenesis of OA and provide insights for the diagnosis and treatment of OA.

MiR-214-3p may alleviate T-2 toxin-induced chondrocyte apoptosis and matrix degradation by regulating NF-κB signaling pathway in vitro

T-2 toxin is part of the most toxic fungal secondary metabolites contaminating different kinds of grains. Previous studies have demonstrated that T-2 toxin can influence the survival of chondrocytes and extracellular matrix (ECM) composition. MiR-214-3p is essential for the homeostasis of chondrocytes and ECM. However, the molecular machinery underlying T-2 toxin-induced chondrocyte apoptosis and ECM degradation remain to be elucidated. The present study aimed to investigate the mechanism of miR-214-3p's involvement in T-2 toxin-induced chondrocyte apoptosis and ECM degradation. Meanwhile, the role of the NF-κB signaling pathway was scrutinized. C28/I2 chondrocytes were treated with 8 ng/ml of T-2 toxin for 24 h, after the pretreatment of miR-214-3p interfering RNAs for 6 h. Gene and protein levels involved in chondrocyte apoptosis and ECM degradation were assessed through RT-PCR and Western blotting. The apoptosis rate of chondrocyte was measured by flow cytometry. Results and data indicated that miR-214-3p was decreased in a dose-dependent manner at different concentrations of T-2 toxin. The enhancement of miR-214-3p could alleviate chondrocyte apoptosis and ECM degradation due to T-2 toxin exposure. The upregulation of miR-214-3p was associated with the decreased expression of apoptosis-promoting genes such as Bax and Cleaved-caspase3/caspase3 as well as the increased expression of anti-apoptotic genes such as Bcl2 and Survivin. Furthermore, miR-214-3p stimulated the relative protein expression of collagen Ⅱ but inhibited the expression of MMP13. Overexpressing miR-214-3p could suppress the relative protein expression of IKKβ and phospho-p65/p65, thus blocking the activation of the NF-κB signaling pathway. The study suggested that the miR-214-3p attenuates T-2 toxin-induced chondrocyte apoptosis and ECM degradation through a potential NF-κB signaling pathway.

Identification and validation of hub genes and potential drugs involved in osteoarthritis through bioinformatics analysis

Purpose: Osteoarthritis (OA) is a common degenerative disease, which still lacks specific therapeutic drugs. Synovitis is one of the most important pathological process in OA. Therefore, we aim to identify and analyze the hub genes and their related networks of OA synovium with bioinformatics tools to provide theoretical basis for potential drugs. Materials and methods: Two datasets were obtained from GEO. DEGs and hub genes of OA synovial tissue were screened through Gene Ontology (GO) annotation, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment as well as protein-protein interaction (PPI) network analysis. Subsequently, the correlation between expression of hub genes and ferroptosis or pyroptosis was analyzed. CeRNA regulatory network was constructed after predicting the upstream miRNAs and lncRNAs. The validation of hub genes was undertook through RT-qPCR and ELISA. Finally, potential drugs targeting pathways and hub genes were identified, followed by the validation of the effect of two potential drugs on OA. Results: A total of 161 commom DEGs were obtained, of which 8 genes were finally identified as hub genes through GO and KEGG enrichment analysis as well as PPI network analysis. Eight genes related to ferroptosis and pyroptosis respectively were significantly correlated to the expression of hub genes. 24 miRNAs and 69 lncRNAs were identified to construct the ceRNA regulatory network. The validation of EGR1, JUN, MYC, FOSL1, and FOSL2 met the trend of bioinformatics analysis. Etanercept and Iguratimod reduced the secretion of MMP-13 and ADAMTS5 of fibroblast-like synoviocyte. Conclusion: EGR1, JUN, MYC, FOSL1, and FOSL2 were identified as hub genes in the development of OA after series of bioinformatics analysis and validation. Etanercept and Iguratimod seemed to have opportunities to be novel drugs for OA.

Integrated Cascade Nanozyme Remodels Chondrocyte Inflammatory Microenvironment in Temporomandibular Joint Osteoarthritis via Inhibiting ROS-NF-κB and MAPK Pathways

Temporomandibular joint osteoarthritis (TMJ OA) is a degenerative joint disease with no complete cure at present. Notably, the inflammatory microenvironment in TMJ OA is modulated by oxidative stress, which impacts cartilage metabolism, chondrocyte apoptosis, inflammatory cytokine release, and extracellular matrix (ECM) synthesis. Thus, it is reasoned that reducing excess reactive oxygen species (ROS) in the chondrocyte microenvironment may be an effective therapeutic strategy for TMJ OA. Recently, cascade nanozymes, including Pt@PCN222-Mn, have been exploited to treat ROS-associated diseases. Nevertheless, cascade nanozymes are not employed for TMJ OA therapy. To fill this gap, it is explored whether the Pt@PCN222-Mn cascade nanozyme could be applied to the treatment of TMJ OA. The in vitro results demonstrate that the Pt@PCN222-Mn nanozyme can inhibit the production of inflammatory factors, the degradation of ECM, and the apoptosis of chondrocytes by inhibiting the ROS-nuclear factor kappa-B (NF-κB_ and mitogen-activated protein kinase signaling pathways. The in vivo results further demonstrate that the Pt@PCN222-Mn nanozyme can delay the progression of TMJ OA in the rat unilateral anterior crossbite model. It is believed that insightful perspectives on the application of nanozymes in TMJ OA will be provided here.

Role of signal transduction pathways in IL-1β-induced apoptosis: Pathological and therapeutic aspects

BACKGROUND

Interleukin-1β (IL-1β) is a pro-inflammatory cytokine mainly produced by monocytes and macrophages with a wide range of biological effects. Evidence has shown that IL-1β plays a vital role in the process of apoptosis; however, the specific mechanisms, by which IL-1β induces apoptosis, vary due to different cellular and experimental conditions. Therefore, this present reviewstudy aimed to systematically review the association between the molecular mechanisms of IL-1β-induced apoptosis in pathological processes and the role of signaling pathways. This article also sought to briefly investigate the potential of signaling pathway-targeted therapy in the prevention and treatment of disease.

METHODS

This is a literature review article. The present discourse aim is first to scrutinize and assess the available literature on IL-1β and apoptosis. The relevant studies using the keywords of "IL-1β-induced apoptosis" and "signaling pathways" were searched in the databases of PubMed, Scopus, Google Scholar, and Web of Science. Gathered relevant material, and extracted information was then assessed.

RESULTS

IL-1β can induce apoptosis in various types of cells under different external stimuli via the mitochondrial pathway, death receptor pathway and endoplasmic reticulum pathway, and that the different pathways are often interconnected. The NF-kB signaling pathway, p38MAPK, and JNK signaling pathways mainly play a proapoptotic part, and the ERK1/2 pathway has a bidirectional role in regulating apoptosis, while activation of the PI3K-Akt signaling pathway can inhibit apoptosis.

CONCLUSION

This review indicates that IL-1β-induced apoptosis plays an important role in pathogenesis and development of pathology of many inflammatory diseases. Elucidating the role of the signaling pathways will aid the development of targeted therapeutic treatments.

Targeting inflammasome-dependent mechanisms as an emerging pharmacological approach for osteoarthritis therapy

Arthritic diseases have attracted enormous scientific interest because of increased worldwide prevalence and represent a significant socioeconomic burden. Osteoarthritis (OA) is the most prevalent form of arthritis. It is a disorder of the diarthrodial joints, characterized by degeneration and loss of articular cartilage associated with adjacent subchondral bone changes. Chronic and unresolving inflammation has been identified as a critical factor driving joint degeneration and pain in OA. Despite numerous attempts at therapeutic intervention, no effective disease-modifying agents targeting OA inflammation are available to the patients. Inflammasomes are protein complexes known to play a critical role in the inflammatory pathology of several diseases, and their roles in OA pathogenesis have become evident over the last decade. In this sense, it is relevant to evaluate the vital role of inflammasomes as potential modulators of pathogenic features in OA. This review will provide an overview and perspectives on why understanding inflammasome activation is critical for identifying effective OA therapies. We elaborate on the contribution of extracellular mediators from the circulatory system and synovial fluid as well as intracellular activators within the synovial fibroblasts and articular chondrocytes toward invoking the inflammasome in OA. We further discuss the merits of emerging inflammasome targeting therapies and speculate on the potential strategies for inflammasome blockade for OA therapy.

Emerging role of lncRNAs in osteoarthritis: An updated review

Osteoarthritis (OA) is a prevalent joint disease, which is associated with progressive articular cartilage loss, synovial inflammation, subchondral sclerosis and meniscus injury. The molecular mechanism underlying OA pathogenesis is multifactorial. Long non-coding RNAs (lncRNAs) are non-protein coding RNAs with length more than 200 nucleotides. They have various functions such as modulating transcription and protein activity, as well as forming endogenous small interfering RNAs (siRNAs) and microRNA (miRNA) sponges. Emerging evidence suggests that lncRNAs might be involved in the pathogenesis of OA which opens up a new avenue for the development of new biomarkers and therapeutic strategies. The purpose of this review is to summarize the current clinical and basic experiments related to lncRNAs and OA with a focus on the extensively studied H19, GAS5, MALAT1, XIST and HOTAIR. The potential translational value of these lncRNAs as therapeutic targets for OA is also discussed.

Epigenetic Regulation in Knee Osteoarthritis

Osteoarthritis (OA) is a complicated disease with both hereditary and environmental causes. Despite an increase in reports of possible OA risk loci, it has become clear that genetics is not the sole cause of osteoarthritis. Epigenetics, which can be triggered by environmental influences and result in transcriptional alterations, may have a role in OA pathogenesis. The majority of recent research on the epigenetics of OA has been focused on DNA methylation, histone modification, and non-coding RNAs. However, this study will explore epigenetic regulation in OA at the present stage. How genetics, environmental variables, and epigenetics interact will be researched, shedding light for future studies. Their possible interaction and control processes open up new avenues for the development of innovative osteoarthritis treatment and diagnostic techniques.

LINC00707 knockdown inhibits IL-1β-induced apoptosis and extracellular matrix degradation of osteoarthritis chondrocytes by the miR-330-5p/FSHR axis

BACKGROUND

Osteoarthritis (OA) is a severe disabling condition that causes major health problems. The roles of lncRNAs in regulating OA progression have been increasingly researched. Based on previously published microarray analysis, LINC00707 is upregulated in OA. This research was done to uncover the function of LINC00707 in IL-1β-induced chondrocyte injury and its possible mechanisms.

METHODS

LINC00707, miR-330-5p, and FSHR expression in OA cartilage tissues were assessed by RT-qPCR. Primary chondrocytes were isolated from OA tissues and treated with IL-1β to establish an in vitro OA model. Under the indicated treatment, chondrocyte apoptosis, senescence, ECM degradation, and inflammation were determined using flow cytometry, TUNEL, SA-β-Gal staining, and ELISA experiments, respectively. Interactions between gene were evaluated using Ago2 RIP and luciferase reporter assays.

RESULTS

LINC00707 and FSHR were elevated, and miR-330-5p was reduced in cartilage tissues of OA patients and in IL-1β-treated primary chondrocytes. Silencing LINC00707 hampered chondrocytes apoptosis, senescence, ECM degradation, and inflammation. LINC00707 acted as a ceRNA to regulate FSHR through controlling miR-330-5p availability. Additionally, both miR-330-5p depletion and FSHR overexpression diminished the effects of silencing LINC00707 in OA progression.

CONCLUSION

Silencing LINC00707 mitigates chondrocyte injury in osteoarthritis via sponging miR-330-5p and inhibiting FSHR.

MicroRNA-4287 alleviates inflammatory response via targeting RIPK1 in osteoarthritis

Studies have confirmed the regulatory effects of microRNAs (miRNAs) in osteoarthritis (OA) progression. MiR-4287 has been identified by a previous study as a downregulated miRNA in chondrocytes treated with IL-1β and TNF-α. However, the function of the underlying mechanism of miR-4287 in OA is elusive. IL-1β-treated chondrocytes were used as OA cell models. RNA expression was accessed using RT-qPCR. Cell Counting Kit-8 (CCK-8) assay was used to determine the chondrocytes' viability and proliferation. The protein levels of inflammation factors (IL-8, IL-6, and TNF-α), matrix metalloproteinases (MMP 1, MMP3, MMP13), and chondrogenic genes (COL2A1, SOX9, and Aggrecan) were detected using western blot analysis. Luciferase reporter assays were performed for interaction exploration. HE staining and Safranin O/Fast Green staining was used to access the pathological changes in OA mouse tissues and cartilage degeneration in OA mouse. MiR-4287 was downregulated in chondrocytes treated with IL-1β and OA mouse models. MiR-4287 overexpression promoted the viability, and proliferation and attenuated the inflammation response and destruction of cartilage in IL-1β-stimulated chondrocytes. Receptor-interacting protein kinase 1 (RIPK1) was a target gene of miR-4287 in chondrocytes. MiR-4287 negatively regulated RIPK1 expression. RIPK1 overexpression was revealed to reverse the miR-4287-mediated effects on proliferation and inflammatory response in IL-1β-stimulated chondrocytes. Moreover, miR-4287 was demonstrated to inhibit the pathological changes, cartilage degeneration and inflammation response in OA mice models. In conclusion, miR-4287 is a critical molecule in OA development, which attenuates inflammatory response in vivo and in vitro by targeting RIPK1.

Synovial mesenchymal stem cell-derived extracellular vesicles alleviate chondrocyte damage during osteoarthritis through microRNA-130b-3p-mediated inhibition of the LRP12/AKT/β-catenin axis

BACKGROUND

Synovial mesenchymal stem cells (SMSCs) have been discussed as promising tools for protecting chondrocytes from loss and inhibiting osteoarthritis (OA). This work infocuses on the function of SMSC-derived extracellular vesicles (EVs) in chondrocytes during OA and the molecular mechanism.

METHODS

EVs were extracted from SMSCs and identified. Chondrocytes were treated with interleukin (IL)-1β to induce an OA-like condition in vitro and then treated with EVs. The proliferation, apoptosis, migration, extracellular matrix (ECM) degradation and inflammation in chondrocytes were examined. Key microRNAs (miRNAs) carried by EVs were screened using a microarray analysis, and the downstream molecules involved were explored using bioinformatic analysis. Rescue experiments were performed to validate the involvements of these molecules in EV-mediated events.

RESULTS

EVs restored proliferation and migration while reduced apoptosis, ECM degradation and the secretion of pro-inflammatory cytokines in chondrocytes induced by IL-1β. miR-130b-3p was significantly elevated in chondrocytes after EVs treatment. Knockdown of miR-130b-3p blocked the protective roles of EVs against IL-1β-induced damage to chondrocytes. miR-130b-3p was found to target LDL receptor related protein 12 (LRP12) mRNA in chondrocytes. Overexpression of LRP12 counteracted the effects of EVs as well and activated the AKT/β-catenin signaling pathway.

CONCLUSION

This study provided evidence that EVs alleviate chondrocyte damage during OA through miR-130b-3p-mediated inhibition of the LRP12/AKT/β-catenin axis. This study may offer novel thoughts into the protection of chondrocytes and the management of OA.

A review of non-coding RNA related to NF-κB signaling pathway in the pathogenesis of osteoarthritis

Osteoarthritis (OA), often called as "wear and tear" arthritis, is the most common form of degenerative joint arthritis and is a leading cause of disability. The nuclear factor-kappaB (NF-κB) transcription factor has long been recognized as a disease-contributing factor for OA. More and more evidences show that targeting NF-κB signaling could offer novel potential therapeutic options for OA damage and reduce the risk of potential side-effects. In recent years, it has been shown that non-coding RNAs(ncRNAs) can trigger the expression of an array of genes and widely activate NF-κB signaling pathway, which induces destruction of the articular joint, leading to OA onset and progression. In this review, we discuss the involvement of NF-κB in OA pathogenesis and how ncRNAs attend and affect OA incidence and evolution, offering novel potential therapeutic options for OA treatment.

Targeting Cell Death: Pyroptosis, Ferroptosis, Apoptosis and Necroptosis in Osteoarthritis

New research has shown that the development of osteoarthritis (OA) is regulated by different mechanisms of cell death and types of cytokines. Therefore, elucidating the mechanism of action among various cytokines, cell death processes and OA is important towards better understanding the pathogenesis and progression of the disease. This paper reviews the pathogenesis of OA in relation to different types of cytokine-triggered cell death. We describe the cell morphological features and molecular mechanisms of pyroptosis, apoptosis, necroptosis, and ferroptosis, and summarize the current research findings defining the molecular mechanisms of action between different cell death types and OA.

Crosstalk Among circRNA/lncRNA, miRNA, and mRNA in Osteoarthritis

Osteoarthritis (OA) is a joint disease that is pervasive in life, and the incidence and mortality of OA are increasing, causing many adverse effects on people's life. Therefore, it is very vital to identify new biomarkers and therapeutic targets in the clinical diagnosis and treatment of OA. ncRNA is a nonprotein-coding RNA that does not translate into proteins but participates in protein translation. At the RNA level, it can perform biological functions. Many studies have found that miRNA, lncRNA, and circRNA are closely related to the course of OA and play important regulatory roles in transcription, post-transcription, and post-translation, which can be used as biological targets for the prevention, diagnosis, and treatment of OA. In this review, we summarized and described the various roles of different types of miRNA, lncRNA, and circRNA in OA, the roles of different lncRNA/circRNA-miRNA-mRNA axis in OA, and the possible prospects of these ncRNAs in clinical application.

Long non-coding RNA SNHG7 upregulates FGF9 to alleviate oxygen and glucose deprivation-induced neuron cell injury in a miR-134-5p-dependent manner

Long non-coding RNA small nucleolar RNA host gene 7 (SNHG7) was reported to regulate the pathogenesis of ischemic stroke. The study aimed to disclose SNHG7 role in oxygen and glucose deprivation (OGD)-induced Neuro-2a (N2a) cell disorders. An OGD injury cell model was established using N2a cells. The expression of SNHG7, microRNA-134-5p (miR-134-5p) and fibroblast growth factor 9 (FGF9) was determined by quantitative real-time polymerase chain reaction. Protein expression was detected by western blot. Cell viability and Lactate Dehydrogenase (LDH) leakage were determined by cell counting kit-8 and LDH activity detection assays. Oxidative stress was investigated by Superoxide Dismutase and Catalase activity assays as well as Malondialdehyde and Reactive Oxygen Species detection kits. Cell apoptosis and caspase-3 activity were severally demonstrated by flow cytometry and caspase-3 activity assays. The interaction between miR-134-5p and SNHG7 or FGF9 was predicted by online databases, and identified by mechanism assays. OGD treatment decreased SNHG7 and FGF9 expression, but increased miR-134-5p expression. OGD treatment repressed cell viability, promoted LDH leakage and induced oxidative stress and apoptosis in N2a cells, which was rescued by SNHG7 overexpression. SNHG7 acted as a sponge for miR-134-5p, and regulated OGD-triggered cell damage by associating with miR-134-5p. Additionally, miR-134-5p depletion protected N2a cells from OGD-induced injury by targeting FGF9. Ectopic SNHG7 expression protected against OGD-induced neuronal cell injury by inducing FGF9 through sponging miR-134-5p, providing a novel therapeutic target for ischemic stroke.

The Emerging Role of Non-Coding RNAs in Osteoarthritis

Osteoarthritis (OS) is the most frequent degenerative condition in the joints, disabling many adults. Several abnormalities in the articular cartilage, subchondral bone, synovial tissue, and meniscus have been detected in the course of OA. Destruction of articular cartilage, the formation of osteophytes, subchondral sclerosis, and hyperplasia of synovial tissue are hallmarks of OA. More recently, several investigations have underscored the regulatory roles of non-coding RNAs (ncRNAs) in OA development. Different classes of non-coding RNAs, including long ncRNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), have been reported to affect the development of OA. The expression level of these transcripts has also been used as diagnostic tools in OA. In the present article, we aimed at reporting the role of these transcripts in this process. We need to give a specific angle on the pathology to provide meaningful thoughts on it.

Non-Coding RNAs: Master Regulators of Inflammasomes in Inflammatory Diseases

Emerging data indicates that non-coding RNAs (ncRNAs) represent more than just “junk sequences” of the genome and have been found to be involved in multiple diseases by regulating various biological process, including the activation of inflammasomes. As an important aspect of innate immunity, inflammasomes are large immune multiprotein complexes that tightly regulate the production of pro-inflammatory cytokines and mediate pyroptosis; the activation of the inflammasomes is a vital biological process in inflammatory diseases. Recent studies have emphasized the function of ncRNAs in the fine control of inflammasomes activation either by directly targeting components of the inflammasomes or by controlling the activity of various factors that control the activation of inflammasomes; consequently, ncRNAs may represent potential therapeutic targets for inflammatory diseases. Understanding the precise role of ncRNAs in controlling the activation of inflammasomes will help us to design targeted therapies for multiple inflammatory diseases. In this review, we summarize the regulatory role and therapeutic potential of ncRNAs in the activation of inflammasomes by focusing on a range of inflammatory diseases, including microbial infection, sterile inflammatory diseases, and fibrosis-related diseases. Our goal is to provide new ideas and perspectives for future research.

LncRNAs as a new regulator of chronic musculoskeletal disorder

OBJECTIVES

In recent years, long non-coding RNAs (lncRNAs) have been found to play a role in the occurrence, progression and prognosis of chronic musculoskeletal disorders.

DESIGN AND METHODS

Literature exploring on PubMed was conducted using the combination of keywords 'LncRNA' and each of the following: 'osteoarthritis', 'rheumatoid arthritis', 'osteoporosis', 'osteogenesis', 'osteoclastogenesis', 'gout arthritis', 'Kashin-Beck disease', 'ankylosing spondylitis', 'cervical spondylotic myelopathy', 'intervertebral disc degeneration', 'human muscle disease' and 'muscle hypertrophy and atrophy'. For each disorder, we focused on the publications in the last five years (5/1/2016-2021/5/1, except for Kashin-Beck disease). Finally, we excluded publications that had been reported in reviews of various musculoskeletal disorders during the last three years. Here, we summarized the progress of research on the role of lncRNA in multiple pathological processes during musculoskeletal disorders.

RESULTS

LncRNAs play a crucial role in regulating downstream gene expression and maintaining function and homeostasis of cells, especially in chondrocytes, synovial cells, osteoblasts, osteoclasts and skeletal muscle cells.

CONCLUSIONS

Understanding the mechanisms of lncRNAs in musculoskeletal disorders may provide promising strategies for clinical practice.

MicroRNA-214-5p aggravates sepsis-related acute kidney injury in mice

Acute kidney injury (AKI) is a devastating comorbidity in sepsis and correlates with a very poor prognosis and increased mortality. Currently, we use lipopolysaccharide (LPS) to establish sepsis-related AKI and try to demonstrate the pathophysiological role of microRNA-214-5p (miR-214-5p) in this process. Mice were intravenously injected with the miR-214-5p agomir, antagomir or negative controls for three consecutive days and then received a single intraperitoneal injection of LPS (10 mg/kg) for 24 h to induce AKI. Besides, the Boston University mouse proximal tubular cell lines were stimulated with LPS (10 μg/ml) for 8 h to investigate the role of miR-214-5p in vitro. To inhibit adenosine monophosphate-activated protein kinase (AMPK), compound C (CpC) was used in vivo. For glucagon-like peptide-1 receptor (GLP-1R) silence, cells were transfected with the small interfering RNA against GLP-1R. miR-214-5p level was upregulated in LPS-treated kidneys and proximal tubular cell lines. The miR-214-5p antagomir reduced LPS-induced renal inflammation and oxidative stress, thereby preventing renal damage and dysfunction. In contrast, the miR-214-5p agomir aggravated LPS-induced inflammation, oxidative stress and AKI in vivo and in vitro. Mechanistically, we found that the miR-214-5p antagomir prevented septic AKI via activating AMPK and that CpC treatment completely abrogated its renoprotective effect in mice. Further detection showed that miR-214-5p directly bound to the 3'-untranslational region of GLP-1R to inhibit GLP-1R/AMPK axis. Our data identify miR-214-5p as a promising therapeutic candidate to treat sepsis-related AKI.

Therapeutic effect and potential mechanisms of intra-articular injections of miR-140-5p on early-stage osteoarthritis in rats

MicroRNAs (miRs) receive extensive attention in osteoarthritis (OA) pathogenesis in recent years, and our previous study confirmed that an intra-articular injection (IAJ) of miR-140-5p alleviates early-stage OA (EOA) progression in rats. This study aims to investigate the therapeutic effect and potential mechanisms of single IAJ (SIAJ) of miR-140-5p on different stage OA and multiple IAJs (MIAJ) of miR-140-5p on EOA. Firstly, the OA model was surgically induced in rats, nine were treated with IAJ of Cy5-miR-140-5p at one week after surgery, and fluorescence distribution was analyzed at different times. Then, 72 rats were treated with SIAJ of miR-140-5p at different stages or MIAJ of miR-140-5p at one week after surgery, and OA progression was evaluated macroscopically and histologically at different times. Finally, the downstream targets and underlying molecular mechanisms of miR-140-5p were predicted by bioinformatics and partially validated. As a result, the intra-articularly injected miR-140-5p entered cartilage and could be taken up by chondrocytes rapidly. IAJ(s) of miR-140-5p improved the behavioral scores, chondrocyte number, cartilage thickness, and pathological scores to varying degrees. Specifically, the earlier a SIAJ of miR-140-5p was administrated, the better the therapeutic effect; meanwhile, MIAJ of miR-140-5p exhibited a better therapeutic effect than SIAJ on EOA. Eighty-four potential target genes and mechanisms of rno-miR-140-5p were predicted, and the effect of miR-140-5p on the potential target genes VEGFA and JAG1 was experimentally validated. Collectively, IAJs of miR-140-5p effectively alleviate EOA progression by modulating multiple biological processes and pathways in rats, representing a promising therapeutic for EOA.

LncRNA CASC19 accelerates chondrocytes apoptosis and proinflammatory cytokine production to exacerbate osteoarthritis development through regulating the miR-152-3p/DDX6 axis

Background

Osteoarthritis (OA) is one kind of degenerative joint disease that happens in articular cartilage and other joint tissues. Long non-coding RNAs (lncRNAs) have been reported to serve as pivotal regulators in many diseases, including OA. However, the role and relevant regulatory mechanisms of CASC19 in OA remain unknown.

Methods

The expression levels of CASC19, miR-152-3p, and DDX6 were identified by reverse-transcription polymerase chain reaction (RT-qPCR). Cell viability and apoptosis were determined by Cell Counting Kit-8 (CCK-8) and flow cytometry assays, respectively. The relationship between miR-152-3p and CASC19 or DDX6 was predicted by bioinformatics tools and verified by the dual-luciferase reporter assay.

Results

CASC19 was verified to exhibit higher expression in OA tissues and cells. Moreover, inhibition of CASC19 weakened proinflammatory cytokine (IL-6, IL-8, and TNF-α) production and cell apoptosis but facilitated cell viability. Experiments of the ceRNA mechanism elucidated that miR-152-3p was a sponge for CASC19, and miR-152-3p targeted DDX6, suggesting that CASC19 sponged miR-152-3p to release DDX6. Finally, results from rescue assays proved that the impacts of CASC19 silencing on chondrocytes apoptosis and proinflammatory cytokine production could be reversed by DDX6 overexpression.

Conclusions

It was concluded that lncRNA CASC19 accelerated chondrocytes apoptosis and proinflammatory cytokine production to exacerbate osteoarthritis development through regulating the miR-152-3p/DDX6 axis. These findings may offer an effective biological target for OA treatment.

Regulation of Osteoclastogenesis and Bone Resorption by miRNAs

Osteoclasts are specialized bone-resorbing cells that contribute to physiological bone development and remodeling in bone metabolism throughout life. Abnormal production and activation of osteoclasts lead to excessive bone resorption in pathological conditions, such as in osteoporosis and in arthritic diseases with bone destruction. Recent epigenetic studies have shed novel insight into the dogma of the regulation of gene expression. microRNAs belong to a category of epigenetic regulators, which post-transcriptionally regulate and silence target gene expression, and thereby control a variety of biological events. In this review, we discuss miRNA biogenesis, the mechanisms utilized by miRNAs, several miRNAs that play important roles in osteoclast differentiation, function, survival and osteoblast-to-osteoclast communication, and their translational potential and challenges in bone biology and skeletal diseases.