MiR-223-3p inhibits inflammation and pyroptosis in monosodium urate-induced rats and fibroblast-like synoviocytes by targeting NLRP3

Mechanism of sodium butyrate, a metabolite of gut microbiota, regulating cardiac fibroblast transdifferentiation via the NLRP3/Caspase-1 pyroptosis pathway

BACKGROUND

Cardiac fibroblasts (CFs) are activated after initial injury, and then differentiate into myofibroblasts (MFs), which play a pivotal role as the primary mediator cells in pathological remodeling. Sodium butyrate (NaB), being a metabolite of gut microbiota, exhibits anti-inflammatory property in local therapies on sites other than the intestine. Thus, this study aimed to probe the mechanism by which NaB regulates CFs transdifferentiation through the NLRP3/Caspase-1 pyroptosis pathway.

METHODS

CFs were cultured in vitro and induced into MFs by TGFβ1. CFs were identified by immunofluorescence labelling technique of vimentin and α-SMA, followed by treatment with NaB or NLRP3 inflammasome inhibitor (CY-09) and its activator [nigericin sodium salt (NSS)]. The expression levels of α-SMA, GSDMD-N/NLRP3/cleaved Caspase-1 proteins, and inflammatory factors IL-1β/IL-18/IL-6/IL-10 were determined using immunofluorescence, Western blot and ELISA. Cell proliferation and migration were evaluated using the CCK-8 assay and the cell scratch test, respectively.

RESULTS

Following the induction of TGFβ1, CFs exhibited increased expression levels of α-SMA proteins and IL-6/IL-10, as well as cell proliferative and migratory abilities. TGFβ1 induced CFs to differentiate into MFs, while NaB inhibited this differentiation. NaB inactivated the NLRP3/Caspase-1 pyroptosis pathway. CY-09 demonstrated inhibitory effects on the NLRP3/Caspase-1 pyroptosis pathway, leading to a reduction in TGFβ1-induced CFs transdifferentiation. NSS activated the NLRP3/Caspase-1 pyroptosis pathway, and thus partially counteracting the inhibitory effect of intestinal microbiota metabolite NaB on CFs transdifferentiation.

CONCLUSION

NaB, a metabolite of the gut microbiota, inhibited the activation of the NLRP3/Caspase-1 pyroptosis pathway in TGFβ1-induced CFs, repressed the transdifferentiation of CFs into MFs.

Traditional herbal medicine: Therapeutic potential in acute gouty arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Acute gouty arthritis (AGA) is characterized by a rapid inflammatory reaction caused by the build-up of monosodium urate (MSU) crystals in the tissues surrounding the joints. This condition often associated with hyperuricemia (HUA), is distinguished by its symptoms of intense pain, active inflammation, and swelling of the joints. Traditional approaches in AGA management often fall short of desired outcomes in clinical settings. However, recent ethnopharmacological investigations have been focusing on the potential of Traditional Herbal Medicine (THM) in various forms, exploring their therapeutic impact and targets in AGA treatment.

AIM OF THE REVIEW

This review briefly summarizes the current potential pharmacological mechanisms of THMs - including active ingredients, extracts, and prescriptions -in the treatment of AGA, and discusses the relevant potential mechanisms and molecular targets in depth. The objective of this study is to offer extensive information and a reference point for the exploration of targeted AGA treatment using THMs.

MATERIALS AND METHODS

This review obtained scientific publications focused on in vitro and in vivo studies of anti-AGA THMs conducted between 2013 and 2023. The literature was collected from various journals and electronic databases, including PubMed, Elsevier, ScienceDirect, Web of Science, and Google Scholar. The retrieval and analysis of relevant articles were guided by keywords such as "acute gouty arthritis and Chinese herbal medicine," "acute gouty arthritis herbal prescription," "acute gouty arthritis and immune cells," "acute gouty arthritis and inflammation," "acute gouty arthritis and NOD-like receptor thermoprotein domain associated protein 3 (NLRP3)," "acute gouty arthritis and miRNA," and "acute gouty arthritis and oxidative stress."

RESULTS

We found that AGA has a large number of therapeutic targets, highlighting the effectiveness the potential of THMs in AGA treatment through in vitro and in vivo studies. THMs and their active ingredients can mitigate AGA symptoms through a variety of therapeutic targets, such as influencing macrophage polarization, neutrophils, T cells, natural killer (NK) cells, and addressing factors like inflammation, NLRP3 inflammasome, signaling pathways, oxidative stress, and miRNA multi-target interactions. The anti-AGA properties of THMs, including their active components and prescriptions, were systematically summarized and categorized based on their respective therapeutic targets.

CONCLUSION

phenolic, flavonoid, terpenoid and alkaloid compounds in THMs are considered the key ingredients to improve AGA. THMs and their active ingredients achieve enhanced efficacy through interactions with multiple targets, of which NLRP3 is a main therapeutic target. Nonetheless, given the intricate composition of traditional Chinese medicine (TCM), additional research is required to unravel the underlying mechanisms and molecular targets through which THMs alleviate AGA.

Restoration of epigenetic impairment in the skeletal muscle and chronic inflammation resolution as a therapeutic approach in sarcopenia

Sarcopenia is an age-associated loss of skeletal muscle mass, strength, and function, accompanied by severe adverse health outcomes, such as falls and fractures, functional decline, high health costs, and mortality. Hence, its prevention and treatment have become increasingly urgent. However, despite the wide prevalence and extensive research on sarcopenia, no FDA-approved disease-modifying drugs exist. This is probably due to a poor understanding of the mechanisms underlying its pathophysiology. Recent evidence demonstrate that sarcopenia development is characterized by two key elements: (i) epigenetic dysregulation of multiple molecular pathways associated with sarcopenia pathogenesis, such as protein remodeling, insulin resistance, mitochondria impairments, and (ii) the creation of a systemic, chronic, low-grade inflammation (SCLGI). In this review, we focus on the epigenetic regulators that have been implicated in skeletal muscle deterioration, their individual roles, and possible crosstalk. We also discuss epidrugs, which are the pharmaceuticals with the potential to restore the epigenetic mechanisms deregulated in sarcopenia. In addition, we discuss the mechanisms underlying failed SCLGI resolution in sarcopenia and the potential application of pro-resolving molecules, comprising specialized pro-resolving mediators (SPMs) and their stable mimetics and receptor agonists. These compounds, as well as epidrugs, reveal beneficial effects in preclinical studies related to sarcopenia. Based on these encouraging observations, we propose the combination of epidrugs with SCLI-resolving agents as a new therapeutic approach for sarcopenia that can effectively attenuate of its manifestations.

Challenges and promise of targeting miRNA in rheumatic diseases: a computational approach to identify miRNA association with cell types, cytokines, and disease mechanisms

MicroRNAs (miRNAs) are small non-coding RNAs that alter the expression of target genes at the post-transcriptional level, influencing diverse outcomes in metabolism, cell differentiation, proliferation, cell survival, and cell death. Dysregulated miRNA expression is implicated in various rheumatic conditions, including ankylosing spondylitis (AS), gout, juvenile idiopathic arthritis (JIA), osteoarthritis (OA), psoriatic arthritis, rheumatoid arthritis (RA), Sjogren's syndrome, systemic lupus erythematosus (SLE) and systemic sclerosis. For this review, we used an open-source programming language- PowerShell, to scan the massive number of existing primary research publications on PubMed on miRNAs in these nine diseases to identify and count unique co-occurrences of individual miRNAs and the disease name. These counts were used to rank the top seven most relevant immuno-miRs based on their research volume in each rheumatic disease. Individual miRNAs were also screened for publication with the names of immune cells, cytokines, and pathological processes involved in rheumatic diseases. These occurrences were tabulated into matrices to identify hotspots for research relevance. Based on this information, we summarize the basic and clinical findings for the top three miRNAs - miR-146, miR-155, and miR-21 - whose relevance spans across multiple rheumatic diseases. Furthermore, we highlight some unique miRNAs for each disease and why some rheumatic conditions lack research in this emerging epigenetics field. With the overwhelming number of publications on miRNAs in rheumatic diseases, this review serves as a 'relevance finder' to guide researchers in selecting miRNAs based on the compiled existing knowledge of their involvement in disease pathogenesis. This approach applies to other disease contexts with the end goal of developing miRNA-based therapeutics.

Peptide NCTX15 derived from spider toxin gland effectively relieves hyperuricemia in mice

Hyperuricemia is a clinical disease characterized by a continuous increase in uric acid (UA) due to purine metabolism disorder. As current drug treatments are limited, it is imperative to explore new drugs that offer better safety and efficacy. In this study, Nephila clavata toxin gland homogenates were isolated and purified by exclusion chromatography and high-performance liquid chromatography, resulting in the identification and isolation of a short peptide (NCTX15) with the sequence 'QSGHTFK'. Analysis showed that NCTX15 exhibited no cytotoxicity in mouse macrophages or toxic and hemolytic activity in mice. Notably, NCTX15 inhibited UA production by down-regulating urate transporter 1 and glucose transporter 9 and up-regulating organic anion transporter 1, thus promoting UA excretion. In addition, NCTX15 alleviated the inflammatory response and renal injury by inhibiting the expression of inflammatory factors interleukin-6, interleukin-1β, tumor necrosis factor alpha, NLR family, pyrin domain-containing 3, and pyroptosis-related factor gasdermin D. These results indicate that NCTX15 displayed urate-lowering, anti-inflammatory, and analgesic effects. As the first urate-reducing short peptide isolated from a spider toxin gland homogenate, NCTX15 exhibits considerable potential as a novel drug molecule for anti-gout and hyperuricemia treatment.

MiR-223-3p attenuates M1 macrophage polarization via suppressing the Notch signaling pathway and NLRP3-mediated pyroptosis in experimental autoimmune uveitis

Autoimmune uveitis is an intraocular inflammatory disease with a high blindness rate in developed countries such as the United States. It is pressing to comprehend the pathogenesis of autoimmune uveitis and develop novel schemes for its treatment. In the present research, we demonstrated that the Notch signaling pathway was activated, and the level of miR-223-3p was significantly reduced in rats with experimental autoimmune uveitis (EAU) compared with the level of normal rats. To investigate the relationship between miR-223-3p and Notch signaling, EAU rats received miR-223-3p-carrying lentivirus, miR-223-3p vector-carrying lentivirus (miR-223-3p-N), and γ-secretase inhibitor (DAPT), respectively. The results of Q-PCR, immunological experiments, and flow cytometry analysis all support the hypothesis that both miR-223-3p and DAPT, a Notch signaling pathway inhibitor, had similar inhibitory effects on the EAU pathological process. That is to say, they could both inhibit the activation of the Notch signaling pathway via modulating recombination signal binding protein-Jκ (RBPJ) to restore the polarization imbalance of M/M2 macrophages in EAU rats. In addition, miR-223-3p could also inhibit NLRP3 inflammasome activation and inflammasome-induced pyroptosis in ocular tissues. Taken together, our findings indicate that miR-223-3p serves as an important regulator in M1 macrophage polarization and pyroptosis, thereby alleviating the inflammatory response in uveitis.

Circular RNA hsa_circ_0000175 Serves as a Potential Biomarker for Rheumatoid Arthritis via miR-31-5p/GSDME Axis

Rheumatoid arthritis (RA) is a common inflammatory autoimmune disease characterized by synovial inflammation and joint damage. Previous studies have shown that pyroptosis plays an important role in the pathogenesis of RA. In this study, the effects of circular RNA hsa_circ0000175 on pyroptosis and inflammation of RA were evaluated. Serum levels of circ_0000175 and miR-31-5p were determined by RT-qPCR, and the correlation between them was evaluated by Spearman correlation analysis. Fibroblast-like synoviocytes (FLSs) were extracted and prepared for in vitro study. The subcellular localization of circ_0000175 was detected by FISH assay. Pyroptosis and inflammatory cytokines interleukin (IL)-1β, IL-18 and IL-6 were measured by flow cytometry and ELISA, respectively. RNA pull-down and luciferase reporter assays verified the interaction between circ_0000175 and miR-31-5p. Western blot was used to detect the differential expression of pyroptosis-related factors (GSDME-N, GSDMD-N, cleaved caspase-1 and cleaved caspase-3). Circ_0000175 level was increased but miR-31-5p expression was decreased in PBMCs of RA patients and LPS/ATP-treated FLSs, companied with negative correlation. Moreover, miR-31-5p was a target of circ_0000175 in RA-FLSs. Silencing of circ_0000175 or overexpression of miR-31-5p significantly alleviated LPS/ATP-induced pyroptosis in FLSs through both caspase-1/GSDMD and caspase-3/GSDME pathways. Additionally, GSDME was identified as the target of miR-31-5p. The inhibitory effects of circ_0000175 depletion on pyroptosis and inflammation in RA-FLSs treated with LPS/ATP were strengthened by GSDME knockdown. Circ_0000175 can induce pyroptosis and trigger inflammatory response during the occurrence of RA through the miR-31-5p/GSDME axis, which provides a novel therapeutic target for RA treatment.

New Potentiality of Bioactive Substances: Regulating the NLRP3 Inflammasome in Autoimmune Diseases

The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is an essential component of the human innate immune system, and is closely associated with adaptive immunity. In most cases, the activation of the NLRP3 inflammasome requires priming and activating, which are influenced by various ion flux signals and regulated by various enzymes. Aberrant functions of intracellular NLRP3 inflammasomes promote the occurrence and development of autoimmune diseases, with the majority of studies currently focused on rheumatoid arthritis, systemic lupus erythematosus and systemic sclerosis. In recent years, a number of bioactive substances have shown new potentiality for regulating the NLRP3 inflammasome in autoimmune diseases. This review provides a concise overview of the composition, functions, and regulation of the NLRP3 inflammasome. Additionally, we focus on the newly discovered bioactive substances for regulating the NLRP3 inflammasome in autoimmune diseases in the past three years.

Mechanistic and therapeutic insights into the function of NLRP3 inflammasome in sterile arthritis

The NLRP3 inflammasome, which belongs to the pyrin domain containing 3 family of NOD-like receptors, has a significant impact on both the innate and adaptive immune responses. Regulating host immune function and protecting against microbial invasion and cell damage, the NLRP3 inflammasome plays a crucial role. By triggering caspase-1, it facilitates the development of the inflammatory cytokines IL-1β and IL-18, and triggers cell pyroptosis, resulting in cell lysis and demise. Common sterile arthritis includes osteoarthritis (OA), rheumatoid arthritis (RA) and gouty arthritis (GA), all of which manifest as bone destruction and synovial inflammation in a complex inflammatory state, placing a significant medical burden on the families of patients and government agencies. In the past few years, there has been a growing interest in investigating the impact of cell pyroptosis on arthritis development, particularly the widespread occurrence of pyroptosis mediated by the NLRP3 inflammasome. The NLRP3 inflammasome's biological properties are briefly described in this review, along with the presentation of the fundamental processes of pyroptosis resulting from its activation. Furthermore, we provide a summary of the advancements made in studying the NLRP3 inflammasome in various forms of arthritis and enumerate the intervention approaches that target the NLRP3-mediated pyroptosis, either directly or indirectly. These discoveries lay the groundwork for future investigations on medications for arthritis, offering fresh approaches for the clinical identification and treatment of this condition.

miR-223: a key regulator of pulmonary inflammation

Small noncoding RNAs, known as microRNAs (miRNAs), are vital for the regulation of diverse biological processes. miR-223, an evolutionarily conserved anti-inflammatory miRNA expressed in cells of the myeloid lineage, has been implicated in the regulation of monocyte-macrophage differentiation, proinflammatory responses, and the recruitment of neutrophils. The biological functions of this gene are regulated by its expression levels in cells or tissues. In this review, we first outline the regulatory role of miR-223 in granulocytes, macrophages, endothelial cells, epithelial cells and dendritic cells (DCs). Then, we summarize the possible role of miR-223 in chronic obstructive pulmonary disease (COPD), acute lung injury (ALI), coronavirus disease 2019 (COVID-19) and other pulmonary inflammatory diseases to better understand the molecular regulatory networks in pulmonary inflammatory diseases.

New drug targets for the treatment of gout arthritis: what's new?

INTRODUCTION

Gout arthritis (GA) is an intermittent inflammatory disease affecting approximately 10% of the worldwide population. Symptomatic phases (acute flares) are timely spaced by asymptomatic periods. During an acute attack, redness, joint swelling, limited movement, and excruciating pain are common symptoms. However, the current available therapies are not fully effective in reducing symptoms and offer numerous side effects. Therefore, unveiling new drug targets and effector molecules are required in developing novel GA therapeutics.

AREAS COVERED

This review discusses the pathophysiological mechanisms of GA and explores potential pharmacological targets to ameliorate disease outcome. In addition, we listed promising pre-clinical studies demonstrating effector molecules with therapeutical potential. Among those, we emphasized the importance of natural products, including traditional Chinese medicine formulas and their multitarget mechanisms of action.

EXPERT OPINION

In our search, we observed that there is a massive gap between pre-clinical and clinical knowledge. Only a minority (4.4%) of clinical trials aimed to intervene by applying natural products or current hot targets described herein. In this sense, we envisage four possibilities for GA therapeutics, which include the repurposing of existing therapies, ALX/FPR2 agonism for improvement in disease outcome, the use of multitarget drugs (e.g. natural products), and targeting the neuroinflammatory component of GA.

A Novel Defined PANoptosis-Related miRNA Signature for Predicting the Prognosis and Immune Characteristics in Clear Cell Renal Cell Carcinoma: A miRNA Signature for the Prognosis of ccRCC

Clear cell renal cell carcinoma (ccRCC) is one of the most prevalent cancers, and PANoptosis is a distinct, inflammatory-programmed cell death regulated by the PANoptosome. The essential regulators of cancer occurrence and progression are microRNAs (miRNAs). However, the potential function of PANoptosis-related microRNAs (PRMs) in ccRCC remains obscure. This study retrieved ccRCC samples from The Cancer Genome Atlas database and three Gene Expression Omnibus datasets. PRMs were recognized based on previous reports in the scientific literature. Regression analyses were used to identify the prognosis PRMs and construct a PANoptosis-related miRNA prognostic signature based on the risk score. We discovered that high-risk patients had poorer survival prognoses and were significantly linked to high-grade and advanced-stage tumors, using a variety of R software packages and web analysis tools. Furthermore, we demonstrated that the low-risk group had significant changes in their metabolic pathways. In contrast, the high-risk group was characterized by high immune cell infiltration, immune checkpoint expression, and low half-maximum inhibition concentration (IC50) values of chemotherapeutic agents. This suggests that high-risk patients may benefit more from immunotherapy and chemotherapy. In conclusion, we constructed a PANoptosis-related microRNA signature and revealed its potential significance in clinicopathological features and tumor immunity, thereby providing new precise treatment strategies.

miRNA155-5P participated in DDX3X targeted regulation of pyroptosis to attenuate renal ischemia/reperfusion injury

BACKGROUND

Renal ischemia/reperfusion injury (IRI) induced pathological damage to renal microvessels and tubular epithelial cells through multiple factors. However, studies investigated whether miRNA155-5P targeted DDX3X to attenuate pyroptosis were scarce.

RESULTS

The expression of pyroptosis-related proteins (caspase-1, interleukin-1β (IL-1β), NOD-like receptor family pyrin domain containing 3 (NLRP3), and IL-18) were up-regulated in the IRI group. Additionally, miR-155-5p was higher in the IRI group comparing with the sham group. The DDX3X was inhibited by the miR-155-5p mimic more than in the other groups. DEAD-box Helicase 3 X-Linked (DDX3X), NLRP3, caspase-1, IL-1β, IL-18, LDH, and pyroptosis rates were higher in all H/R groups than in the control group. These indicators were higher in the miR-155-5p mimic group than in the H/R and the miR-155-5p mimic negative control (NC) group.

CONCLUSIONS

Current findings suggested that miR-155-5p decreased the inflammation involved in pyroptosis by downregulating the DDX3X/NLRP3/caspase-1 pathway.

METHODS

Using the models of IRI in mouse and the hypoxia-reoxygenation (H/R)-induced injury in human renal proximal tubular epithelial cells (HK-2 cells), we analyzed the changes in renal pathology and the expression of factors correlated with pyroptosis and DDX3X. Real-time reverse transcription polymerase chain reaction (RT-PCR) detected miRNAs and enzyme-linked immunosorbent assay (ELISA) was used to detect lactic dehydrogenase activity. The StarBase and luciferase assays examined the specific interplay of DDX3X and miRNA155-5P. In the IRI group, severe renal tissue damage, swelling, and inflammation were examined.

The regulation of self-tolerance and the role of inflammasome molecules

Inflammasome molecules make up a family of receptors that typically function to initiate a proinflammatory response upon infection by microbial pathogens. Dysregulation of inflammasome activity has been linked to unwanted chronic inflammation, which has also been implicated in certain autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, type 1 diabetes, systemic lupus erythematosus, and related animal models. Classical inflammasome activation-dependent events have intrinsic and extrinsic effects on both innate and adaptive immune effectors, as well as resident cells in the target tissue, which all can contribute to an autoimmune response. Recently, inflammasome molecules have also been found to regulate the differentiation and function of immune effector cells independent of classical inflammasome-activated inflammation. These alternative functions for inflammasome molecules shape the nature of the adaptive immune response, that in turn can either promote or suppress the progression of autoimmunity. In this review we will summarize the roles of inflammasome molecules in regulating self-tolerance and the development of autoimmunity.

Genetic and Epigenetic Regulation of the Innate Immune Response to Gout

Gout is a disease caused by uric acid (UA) accumulation in the joints, causing inflammation. Two UA forms - monosodium urate (MSU) and soluble uric acid (sUA) have been shown to interact physically with inflammasomes, especially with the nod-like receptor (NLR) family pyrin domain containing 3 (NLRP3), albeit the role of the immune response to UA is poorly understood, given that asymptomatic hyperuricemia does also exist. Macrophage phagocytosis of UA activate NLRP3, lead to cytokines release, and ultimately, lead to chemoattract neutrophils and lymphocytes to the gout flare joint spot. Genetic variants of inflammasome genes and of genes encoding their molecular partners may influence hyperuricemia and gout susceptibility, while also influencing other comorbidities such as metabolic syndrome and cardiovascular diseases. In this review, we summarize the inflammatory responses in acute and chronic gout, specifically focusing on innate immune cell mechanisms and genetic and epigenetic characteristics of participating molecules. Unprecedently, a novel UA binding protein - the neuronal apoptosis inhibitor protein (NAIP) - is suggested as responsible for the asymptomatic hyperuricemia paradox.Abbreviation: β2-integrins: leukocyte-specific adhesion molecules; ABCG2: ATP-binding cassete family/breast cancer-resistant protein; ACR: American college of rheumatology; AIM2: absent in melanoma 2, type of pattern recognition receptor; ALPK1: alpha-protein kinase 1; ANGPTL2: angiopoietin-like protein 2; ASC: apoptosis-associated speck-like protein; BIR: baculovirus inhibitor of apoptosis protein repeat; BIRC1: baculovirus IAP repeat-containing protein 1; BIRC2: baculoviral IAP repeat-containing protein 2; C5a: complement anaphylatoxin; cAMP: cyclic adenosine monophosphate; CARD: caspase activation and recruitment domains; CARD8: caspase recruitment domain-containing protein 8; CASP1: caspase 1; CCL3: chemokine (C-C motif) ligand 3; CD14: cluster of differentiation 14; CD44: cluster of differentiation 44; Cg05102552: DNA-methylation site, usually cytosine followed by guanine nucleotides; contains arbitrary identification code; CIDEC: cell death-inducing DNA fragmentation factor-like effector family; CKD: chronic kidney disease; CNV: copy number variation; CPT1A: carnitine palmitoyl transferase - type 1a; CXCL1: chemokine (CXC motif) ligand 1; DAMPs: damage associated molecular patterns; DC: dendritic cells; DNMT(1): maintenance DNA methyltransferase; eQTL: expression quantitative trait loci; ERK1: extracellular signal-regulated kinase 1; ERK2: extracellular signal-regulated kinase 2; EULAR: European league against rheumatism; GMCSF: granulocyte-macrophage colony-stimulating factor; GWAS: global wide association studies; H3K27me3: tri-methylation at the 27th lysine residue of the histone h3 protein; H3K4me1: mono-methylation at the 4th lysine residue of the histone h3 protein; H3K4me3: tri-methylation at the 4th lysine residue of the histone h3 protein; HOTAIR: human gene located between hoxc11 and hoxc12 on chromosome 12; IκBα: cytoplasmatic protein/Nf-κb transcription inhibitor; IAP: inhibitory apoptosis protein; IFNγ: interferon gamma; IL-1β: interleukin 1 beta; IL-12: interleukin 12; IL-17: interleukin 17; IL18: interleukin 18; IL1R1: interleukin-1 receptor; IL-1Ra: interleukin-1 receptor antagonist; IL-22: interleukin 22; IL-23: interleukin 23; IL23R: interleukin 23 receptor; IL-33: interleukin 33; IL-6: interleukin 6; IMP: inosine monophosphate; INSIG1: insulin-induced gene 1; JNK1: c-jun n-terminal kinase 1; lncRNA: long non-coding ribonucleic acid; LRR: leucine-rich repeats; miR: mature non-coding microRNAs measuring from 20 to 24 nucleotides, animal origin; miR-1: miR followed by arbitrary identification code; miR-145: miR followed by arbitrary identification code; miR-146a: miR followed by arbitrary identification code, "a" stands for mir family; "a" family presents similar mir sequence to "b" family, but different precursors; miR-20b: miR followed by arbitrary identification code; "b" stands for mir family; "b" family presents similar mir sequence to "a" family, but different precursors; miR-221: miR - followed by arbitrary identification code; miR-221-5p: miR followed by arbitrary identification code; "5p" indicates different mature miRNAs generated from the 5' arm of the pre-miRNA hairpin; miR-223: miR followed by arbitrary identification code; miR-223-3p: mir followed by arbitrary identification code; "3p" indicates different mature miRNAs generated from the 3' arm of the pre-miRNA hairpin; miR-22-3p: miR followed by arbitrary identification code, "3p" indicates different mature miRNAs generated from the 3' arm of the pre-miRNA hairpin; MLKL: mixed lineage kinase domain-like pseudo kinase; MM2P: inductor of m2-macrophage polarization; MSU: monosodium urate; mTOR: mammalian target of rapamycin; MyD88: myeloid differentiation primary response 88; n-3-PUFAs: n-3-polyunsaturated fatty-acids; NACHT: acronym for NAIP (neuronal apoptosis inhibitor protein), C2TA (MHC class 2 transcription activator), HET-E (incompatibility locus protein from podospora anserina) and TP1 (telomerase-associated protein); NAIP: neuronal apoptosis inhibitory protein (human); Naip1: neuronal apoptosis inhibitory protein type 1 (murine); Naip5: neuronal apoptosis inhibitory protein type 5 (murine); Naip6: neuronal apoptosis inhibitory protein type 6 (murine); NBD: nucleotide-binding domain; Nek7: smallest NIMA-related kinase; NET: neutrophil extracellular traps; Nf-κB: nuclear factor kappa-light-chain-enhancer of activated b cells; NFIL3: nuclear-factor, interleukin 3 regulated protein; NIIMA: network of immunity in infection, malignancy, and autoimmunity; NLR: nod-like receptor; NLRA: nod-like receptor NLRA containing acidic domain; NLRB: nod-like receptor NLRA containing BIR domain; NLRC: nod-like receptor NLRA containing CARD domain; NLRC4: nod-like receptor family CARD domain containing 4; NLRP: nod-like receptor NLRA containing PYD domain; NLRP1: nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 1; NLRP12: nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 12; NLRP3: nod-like receptor family pyrin domain containing 3; NOD2: nucleotide-binding oligomerization domain; NRBP1: nuclear receptor-binding protein; Nrf2: nuclear factor erythroid 2-related factor 2; OR: odds ratio; P2X: group of membrane ion channels activated by the binding of extracellular; P2X7: p2x purinoceptor 7 gene; p38: member of the mitogen-activated protein kinase family; PAMPs: pathogen associated molecular patters; PBMC: peripheral blood mononuclear cells; PGGT1B: geranylgeranyl transferase type-1 subunit beta; PHGDH: phosphoglycerate dehydrogenase; PI3-K: phospho-inositol; PPARγ: peroxisome proliferator-activated receptor gamma; PPARGC1B: peroxisome proliferative activated receptor, gamma, coactivator 1 beta; PR3: proteinase 3 antigen; Pro-CASP1: inactive precursor of caspase 1; Pro-IL1β: inactive precursor of interleukin 1 beta; PRR: pattern recognition receptors; PYD: pyrin domain; RAPTOR: regulatory associated protein of mTOR complex 1; RAS: renin-angiotensin system; REDD1: regulated in DNA damage and development 1; ROS: reactive oxygen species; rs000*G: single nuclear polymorphism, "*G" is related to snp where replaced nucleotide is guanine, usually preceded by an id number; SLC2A9: solute carrier family 2, member 9; SLC7A11: solute carrier family 7, member 11; SMA: smooth muscular atrophy; Smac: second mitochondrial-derived activator of caspases; SNP: single nuclear polymorphism; Sp3: specificity protein 3; ST2: serum stimulation-2; STK11: serine/threonine kinase 11; sUA: soluble uric acid; Syk: spleen tyrosine kinase; TAK1: transforming growth factor beta activated kinase; Th1: type 1 helper T cells; Th17: type 17 helper T cells; Th2: type 2 helper T cells; Th22: type 22 helper T cells; TLR: tool-like receptor; TLR2: toll-like receptor 2; TLR4: toll-like receptor 4; TNFα: tumor necrosis factor alpha; TNFR1: tumor necrosis factor receptor 1; TNFR2: tumor necrosis factor receptor 2; UA: uric acid; UBAP1: ubiquitin associated protein; ULT: urate-lowering therapy; URAT1: urate transporter 1; VDAC1: voltage-dependent anion-selective channel 1.

Role of NLRP3 in the pathogenesis and treatment of gout arthritis

Gout arthritis (GA) is a common and curable type of inflammatory arthritis that has been attributed to a combination of genetic, environmental and metabolic factors. Chronic deposition of monosodium urate (MSU) crystals in articular and periarticular spaces as well as subsequent activation of innate immune system in the condition of persistent hyperuricemia are the core mechanisms of GA. As is well known, drugs for GA therapy primarily consists of rapidly acting anti-inflammatory agents and life-long uric acid lowering agents, and their therapeutic outcomes are far from satisfactory. Although MSU crystals in articular cartilage detected by arthrosonography or in synovial fluid found by polarization microscopy are conclusive proofs for GA, the exact molecular mechanism of NLRP3 inflammasome activation in the course of GA still remains mysterious, severely restricting the early diagnosis and therapy of GA. On the one hand, the activation of Nod-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome requires nuclear factor kappa B (NF-κB)-dependent transcriptional enhancement of NLRP3, precursor (pro)-caspase-1 and pro-IL-1β, as well as the assembly of NLRP3 inflammasome complex and sustained release of inflammatory mediators and cytokines such as IL-1β, IL-18 and caspase-1. On the other hand, NLRP3 inflammasome activated by MSU crystals is particularly relevant to the initiation and progression of GA, and thus may represent a prospective diagnostic biomarker and therapeutic target. As a result, pharmacological inhibition of the assembly and activation of NLRP3 inflammasome may also be a promising avenue for GA therapy. Herein, we first introduced the functional role of NLRP3 inflammasome activation and relevant biological mechanisms in GA based on currently available evidence. Then, we systematically reviewed therapeutic strategies for targeting NLRP3 by potentially effective agents such as natural products, novel compounds and noncoding RNAs (ncRNAs) in the treatment of MSU-induced GA mouse models. In conclusion, our present review may have significant implications for the pathogenesis, diagnosis and therapy of GA.

Pyroptosis in inflammatory bone diseases: Molecular insights and targeting strategies

Inflammatory bone diseases include osteoarthritis (OA) and rheumatoid arthritis (RA), which can cause severe bone damage in a chronic inflammation state, putting tremendous pressure on the patients' families and government agencies regarding medical costs. In addition, the complexity of osteoimmunology makes research on these diseases difficult. Hence, it is urgent to determine the potential mechanisms and find effective drugs to target inflammatory bone diseases to reduce the negative effects of these diseases. Recently, pyroptosis, a gasdermin-induced necrotic cell death featuring secretion of pro-inflammatory cytokines and lysis, has become widely known. Based on the effect of pyroptosis on immunity, this process has gradually emerged as a vital component in the etiopathogenesis of inflammatory bone diseases. Herein, we review the characteristics and mechanisms of pyroptosis and then focus on its clinical significance in inflammatory bone diseases. In addition, we summarize the current research progress of drugs targeting pyroptosis to enhance the therapeutic efficacy of inflammatory bone diseases and provide new insights for future directions.

LncRNA DLX6-AS1 promotes microglial inflammatory response in Parkinson's disease by regulating the miR-223-3p/NRP1 axis

Parkinson's disease (PD) is a prevailing neurodegenerative disorder. This study discussed the mechanism of lncRNA distal-less homeobox 6 antisense 1 (DLX6-AS1) on inflammatory responses in PD. With healthy male C57BL/6 mice (8-10 weeks) and BV2 microglia as study subjects, we established PD models in vivo/in vitro by injection of 1-methyl-4-phenyl-2, 3, 6-tetrahydropyridine (MPTP) for 4 weeks and treatment of lipopolysaccharide (LPS) for 24hours, respectively. DLX6-AS1 expression in PD mice and BV2 microglia was examined using reverse transcription quantitative-polymerase chain reaction and then down-regulated via stereotaxic catheter injection or cell transfection to evaluate its effect on neurological function. Meanwhile, the cell number of TH+/Caspase3+/IBA1+ in substantia nigra, cell viability, and apoptosis rate of BV2 microglia, inflammatory levels, and NLR family pyrin domain containing 3 (NLRP3) inflammasome were determined using immunohistochemistry, MTT assay, flow cytometry, ELISA assay, and Western blot. The binding relationship between miR-223-3p and DLX6-AS1/Neuropilin-1 (NRP1) was verified by dual-luciferase assay and RNA immunoprecipitation assay. After down-regulation of DLX6-AS1, we down-regulated/overexpressed miR-223-3p/NRP1 levels in BV2 microglia. DLX6-AS1 was overexpressed in PD mice. Silencing DLX6-AS1 improved neurological function and alleviated microglial inflammation in PD mice. Specifically, the latency of mice falling from the rotating rod was longer, and the latency of climbing rod test was shorter; TH+ cells increased, while Caspase3+/IBA1+ cells decreased; the levels of inflammatory were lowered. Silencing DLX6-AS1 inhibited LPS-induced inflammation of BV2 microglia. DLX6-AS1 acted as the ceRNA of miR-223-3p to promote NRP1. Down-regulation of miR-223-3p or overexpression of NRP1 partially annulled the effect of silencing DLX6-AS1 on BV2 microglial inflammation. Overall, DLX6-AS1 promotes the microglial inflammatory response in PD through the ceRNA mechanism of miR-223-3p/NRP1.

MiR-223-3p Regulates Autophagy and Inflammation by Targeting ATG16L1 in Fusarium solani-Induced Keratitis

Purpose

Increasing evidence suggested that microRNAs (miRs) are implicated in the regulation of the inflammatory response and autophagy in multiple diseases. The present study aimed to explore the effect of miR-223-3p on inflammation and autophagy in fungal keratitis (FK).

Methods

An FK mouse model was established, and primary corneal stromal cells were isolated by inoculation with Fusarium solani. The expression of miR-223-3p was determined by quantitative RT-PCR. Subsequently, the target gene of miR-223-3p was identified by a dual-luciferase reporter assay. The levels of miR-223-3p were altered by transfecting miR agomir/antagomir to evaluate its effects. Slit-lamp biomicroscopy and hematoxylin and eosin staining were employed to detect corneal damage. The levels of autophagy were assessed by immunofluorescence, Western blotting, mRFP-GFP-LC3 fluorescence microscopy, and electron microscopy. In addition, inflammation was demonstrated by determining the proinflammatory mediators IL-1β and TNF-ɑ.

Results

Our data suggested that miR-223-3p was increased and that autophagic flux was impaired in mouse FK. Then, we confirmed that autophagy-related gene 16L1 (ATG16L1) was a potential target of miR-223-3p and that this miR negatively regulated the expression of ATG16L1. The inhibition of miR-223-3p attenuated inflammation in FK, reduced P62 expression, and increased the ratio of LC3-II/LC3-I, whereas the overexpression of miR-223-3p displayed the opposite results.

Conclusions

Taken together, miR-223-3p might regulate autophagy via targeting ATG16L1 in experimental F. solani keratitis and is associated with the inflammatory response. MiR-223-3p might be a potential therapeutic target for FK.

Role of microRNA alternation in the pathogenesis of gouty arthritis

Gouty arthritis is a common inflammatory disease. The condition is triggered by a disorder of uric acid metabolism, which causes urate deposition and gout flares. MicroRNAs are a class of conserved small non-coding RNAs that bind to the 3' untranslated region (UTR) of mRNA and regulate the expression of a variety of proteins at the post-transcriptional level. In recent years, attention has been focused on the role of miRNAs in various inflammatory diseases, including gouty arthritis. It is thought that miRNAs may regulate immune function and inflammatory responses, thereby influencing the onset and progression of the disease. This article mainly reviewed the roles of miRNAs in the pathogenesis of gouty arthritis and prospected their potential as diagnostic and prognostic relevant biomarkers and as possible therapeutic targets.

LncRNA MIR155HG functions as a ceRNA of miR-223-3p to promote cell pyroptosis in human degenerative NP cells

Nucleus pulposus (NP) cell pyroptosis plays a critical role in the pathogenesis of intervertebral disk degeneration (IDD). MIR155 host gene (MIR155HG) is a long non-coding RNA with pro-inflammatory activity. However, very little is known about its role in NP cell pyroptosis. This study aimed to observe the impact of MIR155HG on cell pyroptosis and to explore the underlying mechanism in human degenerative NP cells. Our results demonstrated that MIR155HG expression was significantly increased in human degenerative NP tissue samples and showed a positive correlation with Pfirrmann score. Overexpression of MIR155HG through a lentiviral vector decreased miR-223-3p levels, up-regulated NLRP3 expression and induced cell pyroptosis in human degenerative NP cells. A ceRNA action mode was identified among MIR155HG, miR-223-3p, and NLRP3. The stimulatory effect of MIR155HG on human degenerative NP cell pyroptosis was significantly reversed by pretreatment with miR-223-3p mimic or NLRP3 siRNA. In summary, these data suggest that MIR155HG sponges miR-223-3p to promote NLRP3 expression, leading to induction of cell pyroptosis in human degenerative NP cells. Targeting MIR155HG could be a novel and promising strategy to slow down the progression of IDD.

MiR-144-3p induced by SP1 promotes IL-1β-induced pyroptosis in chondrocytes via PTEN/PINK1/Parkin axis

Rheumatoid arthritis (RA) often leads to functional disabilities and deformities. MiRNA plays a vital role in cell pyroptosis. Nevertheless, the function and underlying mechanism of miR-144-3p in pyroptosis during the progression of RA remains unclear. In this study, N1511 cells were stimulated with IL-1β to construct a RA model. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay was performed to assess the cell viability. Cell pyroptosis was detected by flow cytometry. The levels of inflammatory cytokines (TNF-α, IL-6, and IL-18) were assessed by enzyme-linked immunosorbent assay (ELISA). The relationship among specific protein 1 (SP1), microRNA-144-3p (miR-144-3p), and phosphatase and tensin homolog (PTEN) was explored by dual-luciferase reporter assay, RNA immunoprecipitation (RIP), and chromatin immunoprecipitation (ChIP), respectively. The level of miR-144-3p in N1511 cells was upregulated by IL-1β. MiR-144-3p knockdown inhibited IL-1β-induced pyroptosis in N1511 cells, and the expressions of NOD-like receptor family pyrin domain containing 3 (NLRP3), Cleaved caspase-1, Gasdermin D (GSDMD), and Cleaved caspase-3 in IL-1β-stimulated N1511 cells were increased. The levels of inflammatory cytokines in N1511 cells were increased by IL-1β, which were restored by miR-144-3p knockdown. MiR-144-3p knockdown abolished IL-1β-induced inactivation of putative kinase 1 (PINK1)/Parkin RBR E3 ubiquitin-protein (Parkin) signalling. Moreover, transcription factor SP1 could upregulate miR-144-3p expression and miR-144-3p negatively regulated PTEN expression. In summary, MiR-144-3p induced by SP1 could promote IL-1β-induced chondrocyte pyroptosis via inhibiting PTEN expression and suppressing the activation of PINK1/Parkin signalling, which provided a new strategy against RA.

Verification of ferroptosis and pyroptosis and identification of PTGS2 as the hub gene in human coronary artery atherosclerosis

Ferroptosis and pyroptosis have not been fully studied in atherosclerosis. We aimed to investigate the expression of ferroptosis-related and pyroptosis-related proteins in human coronary arteries and analyse correlation with severity of atherosclerosis and clarify the interactions between proteins and possible mechanisms of atherosclerosis. 40 human coronary artery specimens were employed. The atherosclerotic lesions were characterized by Haematoxylin and Eosin (H&E) staining. The expression of prostaglandin-endoperoxide synthase 2 (PTGS2), anti-acyl-CoA synthetase long-chain family member 4 (ACSL4), glutathione peroxidase 4 (GPX4), caspase-1, and NOD-like receptor protein 3 (NLRP3) were analysed by immunohistochemical assay. Correlations between expression of proteins and severity of atherosclerosis were assessed using Spearman correlation analysis. Bioinformatic and coexpression analyses were performed to study the possible pathways and interactions. In the present study, PTGS2, ACSL4, caspase-1, and NLRP3, were upregulated, while GPX4 was downregulated in the advanced stages of atherosclerosis. The severity of atherosclerosis was positively associated with the expression of PTGS2, ACSL4, caspase-1, and NLRP3 and negatively associated with the expression of GPX4. Biological processes of lipid metabolism and inflammation and C-type lectin receptor signaling pathway were enriched. The five proteins interacted with each other directly or indirectly and PTGS2 might be the hub gene of atherosclerosis. Ferroptosis and pyroptosis may regulate the occurrence and development of atherosclerosis. These findings may shed light on new ideas and potential targets for the prevention and treatment of coronary artery atherosclerosis and the proteins may be used as biomarkers for the severity of atherosclerosis.

microRNA-223 Deficiency Exacerbates Acute Inflammatory Response to Monosodium Urate Crystals by Targeting NLRP3

Objective

MicroRNAs were identified as master-switch molecules limiting acute inflammatory response. This study investigated the potential role of microRNA (miR)-223 in the mechanism of gout.

Methods

Wild-type (WT) and miR-223 knock-out (KO) mice were used to evaluate the phenotypes of gout models. Inflammatory cytokines were measured in air pouch and peritoneal cavity lavage fluid. In addition to miR-223 level in gout patients, miR-223 and pro-inflammatory genes were examined in bone marrow-derived macrophages (BMDMs) from mice as well as peripheral blood mononuclear cells from healthy controls (HC) treated with monosodium urate (MSU) crystals in vitro.

Results

MiR-223 was up-regulated in the early phase in BMDMs from WT mice after MSU challenge and decreased rapidly, and this was not observed in miR-223 KO mice in vitro. In addition, miR-223 was required for macrophages homeostasis. In comparison with WT mice in vivo, miR-223 deficiency exacerbated swelling index of MSU-induced inflammation in foot pad and ankle joint models. MiR-223 deficiency also markedly aggravated inflammatory cells infiltration and cytokines release including interleukin (IL)-1β, IL-6 and monocyte chemotactic protein-1 (MCP-1) in the air pouch and peritonitis models. In the in vitro experiments, miR-223 deficiency promoted the inflammatory response by targeting NLR family pyrin domain containing protein 3 (NLRP3). Besides, miR-223 level was down-regulated in gout patients and in HC exposed to MSU in vitro.

Conclusion

MiR-223 was down-regulated in gout patients and miR-223 deficiency exacerbated inflammatory response in diverse murine models, suggesting that up-regulation of miR-223 could be a potential therapeutic strategy for alleviating gouty inflammation.