RIPK2-Mediated Autophagy and Negatively Regulated ROS-NLRP3 Inflammasome Signaling in GMCs Stimulated with High Glucose

Pharmacological inhibition of receptor-interacting protein kinase 2 (RIPK2) elicits neuroprotective effects following experimental ischemic stroke

Ischemic stroke induces a debilitating neurological insult, where inflammatory processes contribute greatly to the expansion and growth of the injury. Receptor-interacting protein kinase 2 (RIPK2) is most well-known for its role as the obligate kinase for NOD1/2 pattern recognition receptor signaling and is implicated in the pathology of various inflammatory conditions. Compared to a sham-operated control, ischemic stroke resulted in a dramatic increase in the active, phosphorylated form of RIPK2, indicating that RIPK2 may be implicated in the response to stroke injury. Here, we assessed the effects of pharmacological inhibition of RIPK2 to improve post-stroke outcomes in mice subjected to experimental ischemic stroke. We found that treatment at the onset of reperfusion with a RIPK2 inhibitor, which inhibits the phosphorylation and activation of RIPK2, resulted in marked improvements in post-stroke behavioral outcomes compared to the vehicle-administered group assessed 24 h after stroke. RIPK2 inhibitor-treated mice exhibited dramatic reductions in infarct volume, concurrent with reduced damage to the blood-brain barrier, as evidenced by reduced levels of active matrix metalloproteinase-9 (MMP-9) and leakage of blood-borne albumin in the ipsilateral cortex. To explore the protective mechanism of RIPK2 inhibition, we next pretreated mice with RIPK2 inhibitor or vehicle and examined transcriptomic alterations occurring in the ischemic brain 6 h after stroke. We observed a dramatic reduction in neuroinflammatory markers in the ipsilateral cortex of the inhibitor-treated group while also attaining a comprehensive view of the vast transcriptomic alterations occurring in the brain with inhibitor treatment through bulk RNA-sequencing of the injured cortex. Overall, we provide significant novel evidence that RIPK2 may represent a viable target for post-stroke pharmacotherapy and potentially other neuroinflammatory conditions.

An aldose reductase inhibitor, WJ-39, ameliorates renal tubular injury in diabetic nephropathy by activating PINK1/Parkin signaling

Renal tubular injury is a critical factor during the early stages of diabetic nephropathy (DN). Proximal tubular epithelial cells, which contain abundant mitochondria essential for intracellular homeostasis, are susceptible to disruptions in the intracellular environment, making them especially vulnerable to diabetic state disorders, which may be attributed to their elevated energy requirements and reliance on aerobic metabolism. It is widely thought that overactivation of the polyol pathway is implicated in DN pathogenesis, and inhibition of aldose reductase (AR), the rate-limiting enzyme in this pathway, represents a promising therapeutic avenue. WJ-39, a novel aldose reductase inhibitor, was investigated in this study for its protective effects on renal tubules in DN and the underlying mechanisms. Our findings revealed that WJ-39 significantly ameliorated the renal tubular morphology in high-fat diet (HFD)/streptozotocin (STZ)-induced DN rats, concurrently inhibiting fibrosis. Notably, WJ-39 safeguarded the structure and function of renal tubular mitochondria by enhancing mitochondrial dynamics. This involved the regulation of mitochondrial fission and fusion proteins and the promotion of PTEN-induced putative kinase 1 (PINK1)/Parkin-mediated mitophagy. Furthermore, WJ-39 demonstrated the inhibition of endogenous apoptosis by mitigating the production of mitochondrial reactive oxygen species (ROS). The protective effects of WJ-39 on mitochondria and apoptosis were countered in high glucose-treated HK-2 cells upon transfection with PINK1 siRNA. Overall, our findings suggest that WJ-39 protects the structural and functional integrity of renal tubules in DN, which may be attributed to its capacity to inhibit aldose reductase activity, activate the PINK1/Parkin signaling pathway, promote mitophagy, and alleviate apoptosis.

Macrophage-derived exosomes promote activation of NLRP3 inflammasome and autophagy deficiency of mesangial cells in diabetic nephropathy

Dysfunction of mesangial cells plays a significant role in the glomerular lesions and is implicated in the pathophysiology of diabetic nephropathy (DN). Macrophages infiltration is the main pathological feature of DN, which can ultimately lead to renal inflammation. Recent studies suggest that the crosstalk between kidney resident cells and inflammatory cells influences the development of DN, and that controlling this crosstalk may help treat DN. Here, we found that DN mice appeared renal pathological damage, including dilation of mesangial matrix and significant infiltration of macrophages, accompanied by increased inflammatory response, NLRP3 inflammasome activation and autophagy deficiency. Additionally, mesangial cells internalized exosomes from high glucose (HG) treated macrophage, resulting the activation of inflammatory cytokines and NLRP3 inflammasome and deficiency of autophagy in vitro and in vivo. Moreover, C57BL/6 mice injected HG-stimulated macrophages-derived exosomes exhibited renal dysfunction and mesangial matrix expansion. Taken together, the present study demonstrated that mesangial cells responded to HG treated macrophage-derived exosomes by promoting the activation of NLRP3 inflammasome and autophagy deficiency, thereby participating in the development of DN.

Natural products in attenuating renal inflammation via inhibiting the NLRP3 inflammasome in diabetic kidney disease

Diabetic kidney disease (DKD) is a prevalent and severe complications of diabetes and serves as the primary cause of end-stage kidney disease (ESKD) globally. Increasing evidence indicates that renal inflammation is critical in the pathogenesis of DKD. The nucleotide - binding oligomerization domain (NOD) - like receptor family pyrin domain containing 3 (NLRP3) inflammasome is the most extensively researched inflammasome complex and is considered a crucial regulator in the pathogenesis of DKD. The activation of NLRP3 inflammasome is regulated by various signaling pathways, including NF- κB, thioredoxin-interacting protein (TXNIP), and non-coding RNAs (ncRNA), among others. Natural products are chemicals extracted from living organisms in nature, and they typically possess pharmacological and biological activities. They are invaluable sources for drug design and development. Research has demonstrated that many natural products can alleviate DKD by targeting the NLRP3 inflammasome. In this review, we highlight the role of the NLRP3 inflammasome in DKD, and the pathways by which natural products fight against DKD via inhibiting the NLRP3 inflammasome activation, so as to provide novel insights for the treatment of DKD.

Paired protein kinases PRKCI-RIPK2 promote pancreatic cancer growth and metastasis via enhancing NF-κB/JNK/ERK phosphorylation

BACKGROUND

Protein kinases play a pivotal role in the malignant evolution of pancreatic cancer (PC) through mediating phosphorylation. Many kinase inhibitors have been developed and translated into clinical use, while the complex pathology of PC confounds their clinical efficacy and warrants the discovery of more effective therapeutic targets.

METHODS

Here, we used the Gene Expression Omnibus (GEO) database and protein kinase datasets to map the PC-related protein kinase-encoding genes. Then, applying Gene Expression and Profiling Interactive Analysis (GEPIA), GEO and Human Protein Atlas, we evaluated gene correlation, gene expression at protein and mRNA levels, as well as survival significance. In addition, we performed protein kinase RIPK2 knockout and overexpression to observe effects of its expression on PC cell proliferation, migration and invasion in vitro, as well as cell apoptosis, reactive oxygen species (ROS) production and autophagy. We established PC subcutaneous xenograft and liver metastasis models to investigate the effects of RIPK2 knockout on PC growth and metastasis. Co-immunoprecipitation and immunofluorescence were utilized to explore the interaction between protein kinases RIPK2 and PRKCI. Polymerase chain reaction and immunoblotting were used to evaluate gene expression and protein phosphorylation level.

RESULTS

We found fourteen kinases aberrantly expressed in human PC and nine kinases with prognosis significance. Among them, RIPK2 with both serine/threonine and tyrosine activities were validated to promote PC cells proliferation, migration and invasion. RIPK2 knockout could inhibit subcutaneous tumor growth and liver metastasis of PC. In addition, RIPK2 knockout suppressed autophagosome formation, increased ROS production and PC cell apoptosis. Importantly, another oncogenic kinase PRKCI could interact with RIPK2 to enhance the phosphorylation of downstream NF-κB, JNK and ERK.

CONCLUSION

Paired protein kinases PRKCI-RIPK2 with multiple phosphorylation activities represent a new pathological mechanism in PC and could provide potential targets for PC therapy.

Walnut-Derived Peptides Promote Autophagy via the Activation of AMPK/mTOR/ULK1 Pathway to Ameliorate Hyperglycemia in Type 2 Diabetic Mice

Autophagy flux plays a significant protective role in type 2 diabetes mellitus (T2DM). However, the mechanisms by which autophagy mediates insulin resistance (IR) to ameliorate T2DM remain unclear. This study explored the hypoglycemic effects and mechanisms of walnut-derived peptides (fraction 3-10 kDa and LP5) in streptozotocin and high-fat-diet-induced T2DM mice. Findings revealed that walnut-derived peptides reduced the levels of blood glucose and FINS and ameliorated IR and dyslipidemia. They also increased SOD and GSH-P_X activities and inhibited the secretion of TNF-α, IL-6, and IL-1β. Additionally, they increased the levels of ATP, COX, SDH, and MMP of liver mitochondria. Western blotting indicated that walnut-derived peptides up-regulated LC3-II/LC3-I and Beclin-1 expression, while they down-regulated p62 expression, which may be associated with the activation of the AMPK/mTOR/ULK1 pathway. Finally, the AMPK activator (AICAR) and inhibitor (Compound C) were used to verify that LP5 could activate autophagy through the AMPK/mTOR/ULK1 pathway in IR HepG2 cells.

Analysis of Long Noncoding RNAs-Related Regulatory Mechanisms in Duchenne Muscular Dystrophy Using a Disease-Related lncRNA-mRNA Pathway Network

Objective

This study aimed to investigate the molecular regulatory mechanisms underpinning Duchenne muscular dystrophy (DMD).

Methods

Using microarray data, differentially expressed long noncoding RNAs (DELs) and DMD-related differentially expressed mRNAs (DEMs) were screened based on the comparative toxicogenomics database, using a cutoff of |log₂ fold change| > 1 and false discovery rate (FDR) < 0.05. Then, protein-protein interaction (PPI), coexpression network of lncRNA-mRNA, and DMD-related lncRNA-mRNA pathway networks were constructed, and functional analyses of the genes in the network were performed. Finally, the proportions of immune cells infiltrating the muscle tissues in DMD were analyzed, and the correlation between the immune cells and expression of the DELs/DEMs was studied.

Results

A total of 46 DELs and 313 DMD-related DEMs were identified. The PPI network revealed STAT1, VEGFA, and CCL2 to be the top three hub genes. The DMD-related lncRNA-mRNA pathway network comprising two pathways, nine DELs, and nine DMD-related DEMs showed that PYCARD, RIPK2, and CASP1 were significantly enriched in the NOD-like receptor signaling pathway, whereas MAP2K2, LUM, RPS6, PDCD4, TWIST1, and HIF1A were significantly enriched with proteoglycans in cancers. The nine DELs in this network were DBET, MBNL1-AS1, MIR29B2CHG, CCDC18-AS1, FAM111A-DT, GAS5, LINC01290, ATP2B1-AS1, and PSMB8-AS1.

Conclusion

The nine DMD-related DEMs and DELs identified in this study may play important roles in the occurrence and progression of DMD through the two pathways of the NOD-like receptor signaling pathway and proteoglycans in cancers.

Integration of transcriptomics and metabolomics reveals pathways involved in MDSC supernatant attenuation of TGF-β1-induced myofibroblastic differentiation of mesenchymal stem cells

Overexposure to transforming growth factor b1 (TGF-β1) induces myofibroblastic differentiation of mesenchymal stem cells (MSCs), which could be attenuated by myeloid-derived suppressor cell (MDSC) supernatant. However, the promyofibroblastic effects of TGF-β1 and the antimyofibroblastic effects of MDSC supernatant in MSCs have not been fully elucidated. To further clarify the latent mechanism and identify underlying therapeutic targets, we used an integrative strategy combining transcriptomics and metabolomics. Bone marrow MSCs were collected 24 h following TGF-β1 and MDSC supernatant treatment for RNA sequencing and untargeted metabolomic analysis. The integrated data were then analyzed to identify significant gene-metabolite correlations. Differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs) were assessed by Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses for exploring the mechanisms of myofibroblastic differentiation of MSCs. The integration of transcriptomic and metabolomic data highlighted significantly coordinated changes in glycolysis/gluconeogenesis and purine metabolism following TGF-β1 and MDSC supernatant treatment. By combining transcriptomic and metabolomic analyses, this study showed that glycolysis/gluconeogenesis and purine metabolism were essential for the myofibroblastic differentiation of MSCs and may serve as promising targets for mechanistic research and clinical practice in the treatment of fibrosis by MDSC supernatant.

Metabolic Dysfunction in the Regulation of the NLRP3 Inflammasome Activation: A Potential Target for Diabetic Nephropathy

Metabolic dysfunction plays a key role in the development of diabetic nephropathy (DN). However, the exact effects and mechanisms are still unclear. The pyrin domain-containing protein 3 (NLRP3) inflammasome, a member of the nod-like receptor family, is considered a crucial inflammatory regulator and plays important roles in the progress of DN. A growing body of evidence suggests that high glucose, high fat, or other metabolite disorders can abnormally activate the NLRP3 inflammasome. Thus, in this review, we discuss the potential function of abnormal metabolites such as saturated fatty acids (SFAs), cholesterol crystals, uric acid (UA), and homocysteine in the NLRP3 inflammasome activation and explain the potential function of metabolic dysfunction regulation of NLRP3 activation in the progress of DN via regulation of inflammatory response and renal interstitial fibrosis (RIF). In addition, the potential mechanisms of metabolism-related drugs, such as metformin and sodium glucose cotransporter (SGLT2) inhibitors, which have served as the suppressors of the NLRP3 inflammasomes, in DN, are also discussed. A better understanding of NLRP3 inflammasome activation in abnormal metabolic microenvironment may provide new insights for the prevention and treatment of DN.

AMPK-mediated autophagy modulates the inflammatory cytokine expression in intestinal epithelial cells induced by high glucose

Introduction: The homeostasis of intestinal epithelial cells (IECs) is disrupted in diabetes, leading to functional changes of the gastrointestinal tract and increasing the risk of diabetic enteropathy. Methods: The aim of this study is to explore the effect of autophagy on the expression of inflammatory factors under high glucose in vitro. The effect of glucose at different concentrations (5, 10, 30 and 50 Mm) on IEC-6 cells was analyzed. Dorsomorphin (AMPK antagonist) and GSK621 (AMPK agonist) were used to examine the relationship between the autophagy and the AMPK/ULK1 signaling pathway in IEC-6 cells. Results: Our results showed that the high glucose significantly inhibited the growth of IECs, and induced more shrinkage and necrosis of cells. Autophagy was inhibited by high glucose. Furthermore, the levels of cytokines, including IL-22, INF-γ, NOS2, and TNF-α, were significantly increased, which were positively correlated with glucose concentration. Additionally, we confirmed that Dorsomorphin down-regulated the expression of p-AMPK and autophagy protein compared with GSK621. Similar, cellular immunofluorescence also detected low autophagy expression. However, GSK621 and Rapamycin increased the level of autophagy and down-regulated the secretion of pro-inflammatory factors compared with Dorsomorphin. Conclusion: Therefore, our results demonstrate that AMPK mediated autophagy may regulate levels of inflammation in IECs and improve cell survival under high glucose.

Silencing of PFKFB3 protects podocytes against high glucose‑induced injury by inducing autophagy

Diabetic nephropathy (DN) is a diabetic complication that threatens the health of patients with diabetes. In addition, podocyte injury can lead to the occurrence of DN. The protein 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) may be associated with diabetes; however, the effects of PFKFB3 knockdown by small interfering (si)RNA on the growth of podocytes remains unknown. To investigate the mechanism by which PFKFB3 mediates podocyte injury, MPC5 mouse podocyte cells were treated with high-glucose (HG), and cell viability and apoptosis were examined by Cell Counting Kit-8 assay and flow cytometry, respectively. In addition, the expression of autophagy-related proteins were measured using western blot analysis and immunofluorescence staining. Cell migration was investigated using a Transwell assay and phalloidin staining was performed to observe the cytoskeleton. The results revealed that silencing of PFKFB3 significantly promoted MPC5 cell viability and inhibited apoptosis. In addition, the migration of the MPC5 cells was notably downregulated by siPFKFB3. Moreover, PFKFB3 silencing notably reversed the HG-induced decrease in oxygen consumption rate, and the HG-induced increase in extracellular acidification rate was rescued by PFKFB3 siRNA. Furthermore, silencing of PFKFB3 induced autophagy in HG-treated podocytes through inactivating phosphorylated (p-)mTOR, p-AMPKα, LC3 and sirtuin 1, and activating p62. In conclusion, silencing of PFKFB3 may protect podocytes from HG-induced injury by inducing autophagy. Therefore, PFKFB3 may serve as a potential target for treatment of DN.

High glucose represses the proliferation of tendon fibroblasts by inhibiting autophagy activation in tendon injury

Diabetic foot ulcer (DFU) is a kind of common and disabling complication of Diabetes Mellitus (DM). Emerging studies have demonstrated that tendon fibroblasts play a crucial role in remodeling phase of wound healing. However, little is known about the mechanism underlying high glucose (HG)-induced decrease in tendon fibroblasts viability. In the present study, the rat models of DFU were established, and collagen deposition, autophagy activation and cell apoptosis in tendon tissues were assessed using Hematoxylin–Eosin (HE) staining, immunohistochemistry (IHC), and TdT-mediated dUTP Nick-End Labeling (TUNEL) assay, respectively. Tendon fibroblasts were isolated from Achilles tendon of the both limbs, and the effect of HG on autophagy activation in tendon fibroblasts was assessed using Western blot analysis, Cell Counting Kit-8 (CCK-8) assay, and flow cytometry. We found that cell apoptosis was increased significantly and autophagy activation was decreased in foot tendon tissues of DFU rats compared with normal tissues. The role of HG in regulating tendon fibroblasts viability was then investigated in vitro, and data showed that HG repressed cell viability and increased cell apoptosis. Furthermore, HG treatment reduced LC3-II expression and increased p62 expression, indicating that HG repressed autophagy activation of tendon fibroblasts. The autophagy activator rapamycin reversed the effect. More importantly, rapamycin alleviated the suppressive role of HG in tendon fibroblasts viability. Taken together, our data demonstrate that HG represses tendon fibroblasts proliferation by inhibiting autophagy activation in tendon injury.

Omarigliptin ameliorated high glucose-induced nucleotide oligomerization domain-like receptor protein 3 (NLRP3) inflammasome activation through activating adenosine monophosphate-activated protein kinase α (AMPKα) in renal glomerular endothelial cells

Diabetic nephropathy (DN) is a complication of diabetes that induces the development of end-stage renal disease (ESRD). The pathogenesis of DN is reported to be closely related to the activation of the NOD-like receptor 3 (NLRP3) inflammasome in renal glomerular endothelial cells. Omarigliptin is a novel dipeptidyl peptidase-4 (DPP-4) inhibitor developed for the management of type II diabetes, it has been recently reported to possess a significant anti-inflammatory property. This study aims to explore the potential therapeutic effects of Omarigliptin on DN. We established an in vitro injury model in human renal glomerular endothelial cells (HrGECs) using high glucose (HG). The severe cytotoxicity and increased oxidative stress in HrGECs induced by HG were pronouncedly reversed by the introduction of Omarigliptin. Furthermore, the activated NLRP3 inflammasome and the excessive production of interleukin 18 (IL-18) and interleukin 1β (IL-1β) in HrGECs induced by incubation with HG were pronouncedly reversed by the introduction of Omarigliptin, accompanied by the activation of the AMPK/mTOR signaling pathway. After the co-administration of the adenosine monophosphate-activated protein kinase α (AMPKα) inhibitor, compound C, the protective effects of Omarigliptin against HG-induced NLRP3 inflammasome activation and production of pro-inflammatory factors were dramatically abolished. Taken together, our data revealed that Omarigliptin ameliorated HG-induced inflammation in renal glomerular endothelial cells through suppressing NLRP3 inflammasome activation mediated by AMPKα.

Mitophagy: A Novel Therapeutic Target for Treating DN

Diabetic nephropathy (DN) is a common microvascular complication of diabetes and one of the leading causes of end-stage renal disease. Tubular damage is an early change and characteristic of DN, and mitochondrial dysfunction plays an important role in the development of DN. Therefore, the timely removal of damaged mitochondria in tubular cells is an effective treatment strategy for DN. Mitophagy is a type of selective autophagy that ensures the timely elimination of damaged mitochondria to protect cells from oxidative stress. In this review, we summarize our understanding of mitochondrial dysfunction and dynamic disorders in tubular cells in DN and the molecular mechanism of mitophagy. Finally, the role of mitophagy in DN and its feasibility as a therapeutic target for DN are discussed.

PCB118 Induces Inflammation of Islet Beta Cells via Activating ROS-NLRP3 Inflammasome Signaling

Background

Diabetes mellitus is a clinical syndrome caused by genetic and environmental factors. Growing evidence suggests that exposure to environmental endocrine disruptors and activation of NLRP3 inflammasome signaling play a vital role in diabetes. However, it is unclear how PCB118, a common environmental endocrine disruptor, contributes to the incidence of diabetes, and its specific mechanism of action is unknown. In this study, we explored whether ROS-induced NLRP3 inflammasome priming and activation were related to PCB118 exposure in mouse islet β-TC-6 cells and the mechanisms of diabetes.

Methods

Mouse islet β-TC-6 cells were cultured with PCB118 as a stimulating factor and ROS inhibitor N-acetyl cysteine (NAC) as an intervention. Cellular toxicity due to PCB118 was detected using the Cell Counting Kit-8; ROS was measured using DCFH-DA; the expressions of NLRP3, procaspase-1, caspase-1, pro-IL-1β, and IL-1β protein were detected by western blot; and IL-6, IL-18, and C-C chemokine ligand 2 (CCL-2) were measured by ELISA.

Results

PCB118 caused significant toxicity to the cells when the stimulation concentration was equal to or greater than 80 nmol/L at 72 hours (p < 0.05) and increased the levels of ROS, NLRP3, caspase-1, IL-1β, IL-6, IL-18, and CCL-2 (p < 0.05); the expressions of procaspase-1 and pro-IL-1β were downregulated in a dose-dependent manner after PCB118 exposure (p < 0.05), which was prevented by pretreatment with NAC (p < 0.05).

Conclusions

PCB118 can activate NLRP3 inflammasome signaling in islet beta cells via the oxidative stress pathway and cause inflammation in islet beta cells. It suggests that environmental endocrine disruptors play an important role in the inflammation of islet beta cells and may contribute to the development of diabetes through NLRP3 inflammatory signaling.

DsbA-L Ameliorates Renal Injury Through the AMPK/NLRP3 Inflammasome Signaling Pathway in Diabetic Nephropathy

NLRP3-mediated inflammation is closely related to the pathological progression of diabetic nephropathy (DN). DsbA-L, an antioxidant enzyme, plays a protective role in a variety of diseases by inhibiting ER stress and regulating metabolism. However, the relationship of DsbA-L with inflammation, especially the NLRP3 inflammasome, has not been examined. In this study, we note that activation of the NLRP3 inflammasome and exacerbated fibrosis were observed in the kidneys of diabetic DsbA-L-knockout mice and were accompanied by decreased phosphorylation of AMP-activated protein kinase (AMPK). Moreover, correlation analysis shows that the phosphorylation of AMPK was negatively correlated with NLRP3 expression and tubular damage. In addition, the decreased AMPK phosphorylation and NLRP3 activation induced by high glucose (HG) in HK-2 cells could be alleviated by the overexpression of DsbA-L. Interestingly, the protective effect of DsbA-L was eliminated after treatment with compound C, a well-known AMPK inhibitor. Our findings suggest that DsbA-L inhibits NLRP3 inflammasome activation by promoting the phosphorylation of AMPK.

The Role of the Interplay Between Autophagy and NLRP3 Inflammasome in Metabolic Disorders

Autophagy is an important and conserved cellular pathway in which cells transmit cytoplasmic contents to lysosomes for degradation. It plays an important role in maintaining the balance of cell composition synthesis, decomposition and reuse, and participates in a variety of physiological and pathological processes. The nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome can induce the maturation and secretion of Interleukin-1 beta (IL-1β) and IL-18 by activating caspase-1. It is involved in many diseases. In recent years, the interplay between autophagy and NLRP3 inflammasome has been reported to contribute to many diseases including metabolic disorders related diseases. In this review, we summarized the recent studies on the interplay between autophagy and NLRP3 inflammasome in metabolic disorders to provide ideas for the relevant basic research in the future.

lncRNA NEAT1 ameliorates LPS‑induced inflammation in MG63 cells by activating autophagy and suppressing the NLRP3 inflammasome

The mechanisms of inflammation in bone and joint tissue are complex and involve long non‑coding RNAs (lncRNAs), which play an important role in this process. The aim of the present study was to screen out differentially expressed genes in human osteoblasts stimulated by inflammation, and to further explore the mechanisms underlying inflammatory responses and the functional activity of human osteoblasts through bioinformatics methods and in vitro experiments. For this purpose, MG63 cells were stimulated with various concentrations of lipopolysaccharide (LPS) for different periods of time to construct an optimal inflammatory model and RNA sequencing was then performed on these cells. The levels of nuclear enriched abundant transcript 1 (NEAT1), various inflammatory factors, Nod‑like receptor protein 3 (NLRP3) protein and osteogenesis‑related proteins, as well as the levels of cell apoptosis‑ and cell cycle‑related markers were measured in MG63 cells stimulated with LPS, transfected with NEAT1 overexpression plasmid and treated with bexarotene by western blot analysis, RT‑qPCR, immunofluorescence, FISH, TEM and flow cytometry. There were 427 differentially expressed genes in the LPS‑stimulated MG63 cells, in which NEAT1 was significantly downregulated. LPS upregulated the expression of inflammatory cytokines and NLRP3, inhibited the expression of autophagy‑related and osteogenesis‑related proteins, promoted apoptosis and altered the cell cycle, which was partially inhibited by NEAT1 overexpression and promoted by bexarotene. LPS stimulated inflammation in the MG63 cells and inhibited the retinoid X receptor (RXR)‑α to downregulate the expression of NEAT1 and decrease levels of autophagy, which promoted the activation of NLRP3 and the release of inflammatory factors, and impaired the functional activity of osteoblasts, thus promoting the development of inflammation.