LIU Wansu， as the foremost of the four great masters of the Jin-Yuan period， established the "theory of fire-heat'' and extended the fire-heat pathogenesis framework to the field of stroke， thereby forming the theory of ''fire-heat inducing stroke''. This achieved a paradigmatic shift in stroke etiology from ''exogenous wind inducing stroke'' to ''fire-heat inducing stroke''. This paper systematically reviews the developmental trajectory of LIU Wansu's ''fire-heat inducing stroke'' theory and explores the social background， academic origins， and core connotations of its theoretical construction. The study found that， based on the ''Nineteen Pathomechanisms'' in the Huangdi's Internal Classic （Huang Di Nei Jing） and combined with clinical practice， LIU Wansu proposed that fire-heat is the fundamental cause of stroke， and that the Six Climatic Factors and the Five Zhi-Emotions can all transform into fire. He further constructed a stratified syndrome differentiation and therapeutic system centered on clearing heat and purging fire， emphasizing differentiated treatment of exterior and interior syndromes， Six Meridians syndrome differentiation， and seasonally adjusted medication. This theory not only resolved the diagnostic and therapeutic dilemmas of febrile epidemic diseases during the Jin-Yuan period， but also exerted a profound influence on later physicians such as ZHANG Zihe and ZHU Danxi， thereby promoting the pluralistic development of stroke theory in traditional Chinese medicine （TCM）. Modern pharmacological research provides solid scientific evidence， confirming that the ''fire-heat'' pathological state is highly associated with key mechanisms such as excessive inflammatory responses， oxidative stress， and excitatory amino acid toxicity following cerebral ischemia. Heat-clearing and fire-purging prescriptions and agents， such as Huanglian Jiedu Tang and baicalin， can exert multi-target neuroprotective effects by regulating inflammatory signaling， enhancing antioxidant enzyme activity， and balancing neurotransmitters. This not only verifies the scientific basis of the ''fire-heat inducing stroke'' theory from a modern biological perspective but also provides conclusive evidence for the clinical application of heat-clearing and fire-purging therapy. LIU Wansu's ''fire-heat inducing stroke'' theory represents a major milestone in the historical understanding of stroke pathogenesis， and its academically transitional insights continue to hold core guiding value for the pattern identification and treatment of ischemic stroke today.

LIU Wansu， as the foremost of the four great masters of the Jin-Yuan period， established the "theory of fire-heat'' and extended the fire-heat pathogenesis framework to the field of stroke， thereby forming the theory of ''fire-heat inducing stroke''. This achieved a paradigmatic shift in stroke etiology from ''exogenous wind inducing stroke'' to ''fire-heat inducing stroke''. This paper systematically reviews the developmental trajectory of LIU Wansu's ''fire-heat inducing stroke'' theory and explores the social background， academic origins， and core connotations of its theoretical construction. The study found that， based on the ''Nineteen Pathomechanisms'' in the Huangdi's Internal Classic （Huang Di Nei Jing） and combined with clinical practice， LIU Wansu proposed that fire-heat is the fundamental cause of stroke， and that the Six Climatic Factors and the Five Zhi-Emotions can all transform into fire. He further constructed a stratified syndrome differentiation and therapeutic system centered on clearing heat and purging fire， emphasizing differentiated treatment of exterior and interior syndromes， Six Meridians syndrome differentiation， and seasonally adjusted medication. This theory not only resolved the diagnostic and therapeutic dilemmas of febrile epidemic diseases during the Jin-Yuan period， but also exerted a profound influence on later physicians such as ZHANG Zihe and ZHU Danxi， thereby promoting the pluralistic development of stroke theory in traditional Chinese medicine （TCM）. Modern pharmacological research provides solid scientific evidence， confirming that the ''fire-heat'' pathological state is highly associated with key mechanisms such as excessive inflammatory responses， oxidative stress， and excitatory amino acid toxicity following cerebral ischemia. Heat-clearing and fire-purging prescriptions and agents， such as Huanglian Jiedu Tang and baicalin， can exert multi-target neuroprotective effects by regulating inflammatory signaling， enhancing antioxidant enzyme activity， and balancing neurotransmitters. This not only verifies the scientific basis of the ''fire-heat inducing stroke'' theory from a modern biological perspective but also provides conclusive evidence for the clinical application of heat-clearing and fire-purging therapy. LIU Wansu's ''fire-heat inducing stroke'' theory represents a major milestone in the historical understanding of stroke pathogenesis， and its academically transitional insights continue to hold core guiding value for the pattern identification and treatment of ischemic stroke today.

ObjectiveTo investigate whether Huanglian Jiedutang （HLJD） and its major active constituents （geniposide， baicalin， and berberine） can inhibit the inflammatory response of BV2 cells under lipopolysaccharide （LPS） stimulation via the high-mobility group protein B1 （HMGB1）/Toll-like receptor 4 （TLR4）/nuclear factor-κB （NF-κB） signaling pathway， and to explore differences in therapeutic efficacy among the three monomers， their combined formula， and HLJD under equal content ratios. MethodsBV2 microglial cells were used as the primary experimental model. Cell viability was assessed using the cell counting kit-8 （CCK-8） method to examine the effects of different concentrations of dimethyl sulfoxide （DMSO， 0.8%， 0.4%， 0.2%， 0.1%， and 0.05%） on cell viability. IncuCyte was employed to monitor the growth of cells under different concentrations of HLJD （200， 100， 50， 25， 12.5， 6.25 mg·L^-1）. Nitric oxide （NO） assay was used to screen the optimal HLJD concentration. High-performance liquid chromatography （HPLC） determined the content of geniposide， baicalin， and berberine in HLJD， and experimental groups were subsequently established according to the relative proportions of these constituents. CCK-8 assay evaluated cell viability under different treatments. Enzyme-linked immunosorbent assay （ELISA） measured levels of inflammatory factors （TNF-α， IL-1β， IL-6， IL-10） in the supernatant. Flow cytometry assessed the effects of treatments on M1-type polarization of BV2 cells. Western blot determined the expression levels of HMGB1， TLR4， and NF-κB-related proteins. ResultsCompared with the blank group， DMSO at concentrations ≤0.2% did not affect cell viability within 48 h. BV2 cell growth plateaued at 24 h after treatment with 200 mg·L^-1 HLJD. Under stimulation with 2 mg·L^-1 LPS， this concentration of HLJD effectively reduced NO release， and 6 h pre-treatment had a stronger inhibitory effect on NO than direct administration. HPLC results showed that 1 mg of HLJD freeze-dried powder contained approximately 24 μg of geniposide， 15 μg of baicalin， and 30 μg of berberine. Based on these ratios， experimental groups were blank， LPS （2 mg·L^-1）， HLJD （200 mg·L^-1）， monomer combination， geniposide （4.8 mg·L^-1）， baicalin （3 mg·L^-1）， and berberine （6 mg·L^-1）. The monomer combination group consisted of all three active constituents dissolved together. LPS and HLJD or its active constituents did not affect cell viability compared with the blank group. LPS significantly increased TNF-α， IL-1β， IL-6， and IL-10 in the supernatant （P<0.01）. HLJD and its active constituents significantly reduced pro-inflammatory factors TNF-α， IL-1β， and IL-6 （P<0.05， P<0.01） while upregulating anti-inflammatory IL-10 （P<0.01）， with the monomer combination showing the strongest effect （P<0.05， P<0.01）. Compared with the blank group， LPS significantly increased the proportion of CD80⁺CD86⁺ （M1-type） BV2 cells （P<0.01）. HLJD and its constituents partially inhibited M1 polarization （P<0.05， P<0.01）， with the monomer combination exhibiting the most pronounced effect （P<0.05， P<0.01）. Compared with the blank group， LPS upregulated HMGB1， TLR4， and NF-κB-related proteins （P<0.01）， whereas HLJD and its active constituents significantly reduced their expression （P<0.05， P<0.01）， with the monomer combination having the strongest regulatory effect （P<0.05， P<0.01）. ConclusionHLJD and its major active constituents （geniposide， baicalin， berberine） can inhibit LPS-induced inflammatory responses in BV2 cells. The combination of the three active constituents demonstrates the most potent anti-inflammatory effect， significantly attenuating M1-type polarization of BV2 cells via the HMGB1/TLR4/NF-κB signaling pathway.

ObjectiveTo reveal the molecular mechanism by which the traditional Chinese medicine compound prescription Qiangjing tablets regulate the aging of the testicular tissue and Leydig cells in rats through the cyclin-dependent kinase 4 （CDK4）-early 2 factor （E2F） signaling pathway. MethodsFor the cell experiment， 2-month-old SPF-grade SD male rats were selected and randomly assigned into a blank control group （administrated with an equal volume of 0.9% sodium chloride injection） and a Qiangjing tablets group （20 rats in each group） according to body weight. The Leydig cell model of aging was established by treatment of TM3 cells with 100 μmol·L^-1 H₂O₂， and the modeling performance was evaluated based on the levels of p16 and p21 determined by Western blot. The antioxidant NAC （1 mmol·L^-1） was used as the positive control for eliminating reactive oxygen species （ROS）. Cells were intervened with Qiangjing tablets-containing serum at low （2.5%）， medium （5%）， and high （10%） concentrations. The testosterone level in the cell supernatant was determined by enzyme-linked immunosorbent assay （ELISA）， and the protein levels of CDK4， E2F1， and E2F2 were analyzed by Western blot. In the animal experiment， 19-month-old naturally aging rats were used as the model group， and 2-month-old rats as the young control group. The positive control group was subcutaneously injected with 5.21 mg·kg^-1·d^-1 testosterone propionate. Qiangjing tablets were administered by gavage at low， medium， and high doses of 0.72， 1.44， 2.88 g·kg^-1·d^-1， respectively. The general conditions of rats were observed， and the protein levels of CDK4， E2F1， and E2F2 in the testicular tissue were determined by Western blot. ResultsIn the cell experiment， compared with the blank control group， the model group showed upregulated expression of CDK4 and E2F1 （P<0.05） and slightly downregulated expression of E2F2. Compared with that in the model group， the expression of CDK4 was upregulated in the NAC group and the low-dose Qiangjing tablets group （P<0.05）， slightly upregulated in the medium-dose Qiangjing tablets group， and downregulated in the high-dose Qiangjing tablets group （P<0.05）. The NAC group showed downregulated expression of E2F1 （P<0.05） and E2F2， and the low-， medium-， and high-dose Qiangjing tablets groups showed downregulated expression of both E2F1 and E2F2 （P<0.05）. Compared with that in the NAC group， the expression of CDK4 was upregulated in the low-dose Qiangjing tablets group and downregulated in the medium-dose and high dose （P<0.05） groups. The expression of E2F1 was down-regulated in all the three dose groups， with statistically significance in the high dose group （P<0.05）， and that of E2F2 were downregulated in all the three dose groups （P<0.05）. In the animal experiment， compared with the young control group， the model group exhibited downregulated expression of CDK4 （P<0.05） and slightly upregulated expression of E2F1 and E2F2. Compared with that in the model group， the expression of CDK4 decreased in the testosterone propionate group and the low-dose Qiangjing tablets group （P<0.05） but increased in the medium-dose （P<0.05） and high-dose groups. In addition， the expression of E2F1 decreased （P<0.05）， and that of E2F2 was slightly elevated. Compared with that in the NAC group， CDK4 expression was elevated in the Qiangjing tablets groups， with statistical significance in the medium- and high-dose groups （P<0.05）. Similarly， the E2F1 expression was also upregulated in the Qiangjing tablets groups， with statistical significance in the medium-dose group （P<0.05）. The expression of E2F2 was downregulated in all the Qiangjing tablets groups. ConclusionQiangjing tablets delay the aging process of Leydig cells and testicular tissue by up-regulating the expression of CDK4 and lowering the levels of E2F1 and E2F2.

Objective: To systematically evaluate the clinical efficacy of topical preparations of Mongolian medicine Manggari hot compress therapy (hereafter referred to as Manggari hot compress therapy) in treating cervical spondylotic radiculopathy (CSR) and explore the possible pharmacological material basis in the formula, providing evidence for the clinical application of Mongolian medicine in the treatment of CSR. Methods: The clinical trial employed a randomized, controlled, open-label, and outcome-assessor-blinded design. The CSR patients who were treated at the Department of Traditional Therapeutics Outpatient Clinic, Xilinguole Meng Mongolian General Hospital between July 1, 2024 and August 31, 2025, were enrolled. They were randomly assigned to three groups: an oral control group (administration of oral administration of mecobalamin tablets combined with cervical electric traction), an experimental group (Manggari external hot compress), and a patch control group (flurbiprofen gel plaster). The intervention lasted two weeks. Before and after treatment, the following subjective indicators were recorded: Mongolian Medicine Syndrome (MMS) score, Visual Analog Scale (VAS) score, Northwick Park Neck Pain Questionnaire (NPQ) score, and tongue morphology. Serum levels of inflammatory markers [tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β)] and oxidative stress markers [malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, and glutathione peroxidase (GSH-Px) activity] were measured using enzyme-linked immunosorbent assay (ELISA). Overall therapeutic efficacy was evaluated. One month after treatment completion, a follow-up assessment was conducted, and the MMS, VAS, and NPQ scores were recorded again for all patients. For the pharmacological substance exploration, ultra-high-performance liquid chromatography-Q-exactive orbitrap-mass (UHPLC-QE-MS) was employed to analyze blood-absorbed prototype components of Manggari, under both positive and negative ion modes. The targeting relationship between the core active compounds and the target protein was validated using molecular docking. Results: This study ultimately included 90 patients with CSR for analysis. Baseline characteristics showed no statistically significant differences among the three groups (P > 0.05). (i) Symptom scores. After treatment, the MMS, VAS, and NPQ scores decreased significantly from baseline in all three groups (P < 0.001). At follow-up, there was no significant difference in MMS, VAS, and NPQ scores of the experimental group compared with those at the end of the treatment (P > 0.05). After treatment, the experimental group showed significantly greater reductions in MMS, VAS, and NPQ scores than oral control and patch control groups (P < 0.001). At follow-up, these differences remained significant (P < 0.001). (ii) Inflammatory and oxidative stress markers. After treatment, serum levels of TNF-α, IL-6, and IL-1β, and MDA activity decreased significantly from baseline in all three groups (P < 0.001), and SOD content and GSH-Px activity increased significantly from baseline (P < 0.05). After treatment, the experimental group had significantly lower serum levels of TNF-α, IL-6, and IL-1β than oral and patch control groups. Additionally, it exhibited lower MDA activity and higher SOD content and GSH-Px activity compared with the two control groups. (P < 0.05). (iii) Overall efficacy. The total effective rate was 93.33% in the experimental group, 86.66% in the oral control group, and 83.33% in the patch control group. (iv) Pharmacological substance analysis. A total of 152 compounds were identified in the blood-absorbed components of Manggari. Among them, the core compounds—4-hydroxycoumarin, N-methylanthranilic acid, genistein, and ginsenoside-Rk1—showed binding energies to the key target proteins TNF-α and IL-1β range from − 4.7 to − 7.1 kcal/mol, with the majority of the binding energies being below − 5.0 kcal/mol, suggesting that it generally has a good binding affinity. Conclusion Mongolian medicine hot compress therapy effectively modulates inflammatory and oxidative stress responses through the combined action of its thermal effects and active pharmaceutical ingredients Manggari. It inhibits cervical nerve root inflammation and alleviates radicular pain, improving clinical symptoms, reducing pain severity, and alleviating neck functional disability.

OBJECTIVE To explore the improvement effect and potential mechanism of ginsenoside F1 （GF1） on allergic rhinitis （AR） rats based on the mitogen-activated protein kinase （MAPK）/signal transducer and activator of transcription 3 （STAT3） pathway. METHODS Male SD rats were divided into a control group （ n ＝15） and a modeling group （ n ＝55）. The AR rat model was established by basic sensitization with ovalbumin followed by local challenge. The successfully modeled rats were randomly assigned to the AR group， low-dose GF1 group [2.5 mg/（kg·d） ] ， high-dose GF1 group [5 mg/（kg·d） ] ， loratadine group （positive control， 1.5 mg/（kg·d） ] ， and high-dose GF1+MAPK activator group [5 mg/（kg·d） GF1+0.2 nmol C16-PAF ] ， with 10 rats in each group. Another 10 rats from the control group were randomly selected as the blank control group. Rats in each group received corresponding drug solutions or normal saline via intranasal instillation and/or oral gavage once daily for 28 consecutive days. After the final administration， AR symptoms were observed and rhinitis symptom scores were assessed. Histopathological changes of the nasal mucosa were examined. The number of inflammatory cells in nasal lavage fluid， serum levels of inflammatory cytokines [interleukin-4 （IL-4）， IL-17， interferon-γ （IFN-γ） ] and immunoglobulin E （IgE）， as well as the density of goblet cells， the number of mast cells， and the expression of MAPK/STAT3 pathway-related proteins in nasal mucosal tissues were measured. RESULTS Compared with the blank control group， the AR group exhibited marked pathological damage to the nasal mucosal epithelium， characterized by interstitial edema and inflammatory cell infiltration. The rhinitis symptom score， the number of macrophages， lymphocytes， eosinophils， neutrophils and mast cells， the density of goblet cells， the levels of IL-4， IL-17 and IgE， as well as the protein phosphorylation levels of p38 MAPK and STAT3 were significantly increased or elevated， while the level of IFN-γ was significantly decreased in the AR group （ P ＜0.05）. Compared with the AR group， all administration groups showed recovery of nasal mucosal epithelial pathological damage and significant improvements in all quantitative indicators， with the high-dose GF1 group and loratadine group showing more pronounced improvements than the low-dose GF1 group （ P ＜0.05）. C16-PAF significantly reversed the ameliorative effects of GF1 on all quantitative indicators （ P ＜0.05）. CONCLUSIONS GF1 can alleviate rhinitis symptoms in AR rats and inhibit inflammatory responses， which may be related to the inhibition of the MAPK/STAT3 pathway activation.

AIM:To observe the therapeutic efficacy of 0.05% cyclosporine combined with olopatadine hydrochlorideeye drops in the treatment of moderate-to-severe pediatric vernal keratoconjunctivitis.METHODS:A prospective randomized controlled study was conducted. Patients with moderate-to-severe pediatric vernal keratoconjunctivitis admitted to the hospital from January to December 2023 were collected and divided into two groups according to the random number table method: the observation group was treated with olopatadine combined with 0.05% cyclosporine hydrochloride eye drops [1 drop per time of 0.05% cyclosporine eye drops(II), four times a day; 1 drop per time of olopatadine hydrochloric eye drops, twice a day]; the control group was treated with sodium hyaluronate combined with olopatadine hydrochloride eye drops(1 drop per time of sodium hyaluronate eye drops, four times a day; 1 drop per time of olopatadine hydrochloric eye drops, twice a day; ). The treatment lasted for 12 wk. The changes in symptom and sign scores of the two groups before treatment, and at 4, 8, and 12 wk after treatment were compared.RESULTS:Totally 42 children(84 eyes)with moderate-to-severe vernal keratoconjunctivitis were enrolled. All patients returned for follow-up visits on time, with no lossto follow-up. The observation group consisted of 21 patients(42 eyes), with 15 males and 6 females, and the average age was 9.00±3.02 y. The control group consisted of 21 patients(42 eyes), with 18 males and 3 females, and the average age was 9.38±3.28 y(all P>0.05). At 4, 8, and 12 wk after treatment, the ocular symptom and sign scores of both groups decreased compared to those before treatment(all P<0.05), and the decrease in the observation group was more significant than that in the control group(P<0.05). During the treatment period, one patient in the observation group experienced a transient mild ocular irritation at the beginning of medication, which was not treated specially and relieved spontaneously after 3 d. No severe adverse reactions such as elevated intraocular pressure or corneal infection occurred in either group during the treatment period.CONCLUSION:The combination of 0.05% cyclosporine and olopatadine hydrochlorideeye drops significantly alleviates the clinical symptoms and signs of moderate-to-severe vernal keratoconjunctivitis, showing favorable safety and efficacy in the treatment of moderate-to-severe pediatric vernal keratoconjunctivitis.

As China accelerates its efforts in deep space exploration and long-duration space missions, including the operationalization of the Tiangong Space Station and the development of manned lunar missions, safeguarding astronauts’ physiological and cognitive functions under extreme space conditions becomes a pressing scientific imperative. Among the multifactorial stressors of spaceflight, microgravity emerges as a particularly potent disruptor of neurobehavioral homeostasis. Dopamine (DA) plays a central role in regulating behavior under space microgravity by influencing reward processing, motivation, executive function and sensorimotor integration. Changes in gravity disrupt dopaminergic signaling at multiple levels, leading to impairments in motor coordination, cognitive flexibility, and emotional stability. Microgravity exposure induces a cascade of neurobiological changes that challenge dopaminergic stability at multiple levels: from the transcriptional regulation of DA synthesis enzymes and the excitability of DA neurons, to receptor distribution dynamics and the efficiency of downstream signaling pathways. These changes involve downregulation of tyrosine hydroxylase in the substantia nigra, reduced phosphorylation of DA receptors, and alterations in vesicular monoamine transporter expression, all of which compromise synaptic DA availability. Experimental findings from space analog studies and simulated microgravity models suggest that gravitational unloading alters striatal and mesocorticolimbic DA circuitry, resulting in diminished motor coordination, impaired vestibular compensation, and decreased cognitive flexibility. These alterations not only compromise astronauts’ operational performance but also elevate the risk of mood disturbances and motivational deficits during prolonged missions. The review systematically synthesizes current findings across multiple domains: molecular neurobiology, behavioral neuroscience, and gravitational physiology. It highlights that maintaining DA homeostasis is pivotal in preserving neuroplasticity, particularly within brain regions critical to adaptation, such as the basal ganglia, prefrontal cortex, and cerebellum. The paper also discusses the dual-edged nature of DA plasticity: while adaptive remodeling of synapses and receptor sensitivity can serve as compensatory mechanisms under stress, chronic dopaminergic imbalance may lead to maladaptive outcomes, such as cognitive rigidity and motor dysregulation. Furthermore, we propose a conceptual framework that integrates homeostatic neuroregulation with the demands of space environmental adaptation. By drawing from interdisciplinary research, the review underscores the potential of multiple intervention strategies including pharmacological treatment, nutritional support, neural stimulation techniques, and most importantly, structured physical exercise. Recent rodent studies demonstrate that treadmill exercise upregulates DA transporter expression in the dorsal striatum, enhances tyrosine hydroxylase activity, and increases DA release during cognitive tasks, indicating both protective and restorative effects on dopaminergic networks. Thus, exercise is highlighted as a key approach because of its sustained effects on DA production, receptor function, and brain plasticity, making it a strong candidate for developing effective measures to support astronauts in maintaining cognitive and emotional stability during space missions. In conclusion, the paper not only underscores the centrality of DA homeostasis in space neuroscience but also reflects the authors’ broader academic viewpoint: understanding the neurochemical substrates of behavior under microgravity is fundamental to both space health and terrestrial neuroscience. By bridging basic neurobiology with applied space medicine, this work contributes to the emerging field of gravitational neurobiology and provides a foundation for future research into individualized performance optimization in extreme environments.

Objective To externally validate a prediction model based on clinical and CT imaging features for the preoperative identification of high-grade patterns (HGP), such as micropapillary and solid subtypes, in early-stage lung adenocarcinoma, in order to guide clinical treatment decisions. Methods This study conducted an external validation of a previously developed prediction model using a cohort of patients with clinical stage ⅠA lung adenocarcinoma from the Fourth Hospital of Hebei Medical University. The model, which incorporated factors including tumor size, density, and lobulation, was assessed for its discrimination, calibration performance, and clinical impact. Results A total of 650 patients (293 males, 357 females; age range: 30-82 years) were included. The validation showed that the model demonstrated good performance in discriminating HGP (area under the curve>0.7). After recalibration, the model's calibration performance was improved. Decision curve analysis (DCA) indicated that at a threshold probability>0.6, the number of HGP patients predicted by the model closely approximated the actual number of cases. Conclusion This study confirms the effectiveness of a clinical and imaging feature-based prediction model for identifying HGP in stage ⅠA lung adenocarcinoma in a clinical setting. Successful application of this model may be significant for determining surgical strategies and improving patients' prognosis. Despite certain limitations, these findings provide new directions for future research.

BACKGROUND: Knee osteoarthritis (OA) is still challenging to prevent or treat. Enhanced endoplasmic reticulum (ER) stress and increased pyroptosis in chondrocytes may be responsible for cartilage degeneration. This study aims to investigate the effect of ER stress on chondrocyte pyroptosis and the upstream regulatory mechanisms, which have rarely been reported. METHODS: The expression of the histone methyltransferase enhancer of zeste homolog 2 (EZH2), microRNA-142-3p (miR-142-3p), and high mobility group box 1 (HMGB1) and the levels of ER stress, pyroptosis, and metabolic markers in normal and OA chondrocytes were investigated by western blotting, quantitative polymerase chain reaction, immunohistochemistry, fluorescence in situ hybridization, fluorescein amidite-tyrosine-valine-alanine-aspartic acid-fluoromethyl ketone (FAM-YVAD-FMK)/Hoechst 33342/propidium iodide (PI) staining, lactate dehydrogenase (LDH) release assays, and cell viability assessments. The effects of EZH2, miR-142-3p, and HMGB1 on ER stress and pyroptosis and the hierarchical regulatory relationship between them were analyzed by chromatin immunoprecipitation, luciferase reporters, gain/loss-of-function assays, and rescue assays in interleukin (IL)-1β-induced OA chondrocytes. The mechanistic contribution of EZH2, miR-142-3p, and HMGB1 to chondrocyte ER stress and pyroptosis and therapeutic prospects were validated radiologically, histologically, and immunohistochemically in surgically induced OA rats. RESULTS: Increased EZH2 and HMGB1, decreased miR-142-3p, enhanced ER stress, and activated pyroptosis in chondrocytes were associated with OA occurrence and progression. EZH2 and HMGB1 exacerbated and miR-142-3p alleviated ER stress and pyroptosis in OA chondrocytes. EZH2 transcriptionally silenced miR-142-3p via H3K27 trimethylation, and miR-142-3p posttranscriptionally silenced HMGB1 by targeting the 3'-UTR of the HMGB1 gene. Moreover, ER stress mediated the effects of EZH2, miR-142-3p, and HMGB1 on chondrocyte pyroptosis. In vivo experiments mechanistically validated the hierarchical regulatory relationship between EZH2, miR-142-3p, and HMGB1 and their effects on chondrocyte ER stress and pyroptosis. CONCLUSIONS A novel EZH2/miR-142-3p/HMGB1 axis mediates chondrocyte pyroptosis and cartilage degeneration by regulating ER stress in OA, contributing novel mechanistic insights into OA pathogenesis and providing potential targets for future therapeutic research.
Enhancer of Zeste Homolog 2 Protein/genetics* ; Osteoarthritis, Knee/pathology* ; Chondrocytes/metabolism* ; Pyroptosis/physiology* ; HMGB1 Protein/genetics* ; MicroRNAs/metabolism* ; Endoplasmic Reticulum Stress/genetics* ; Humans ; Animals ; Rats ; Male ; Rats, Sprague-Dawley ; Middle Aged