ObjectiveTo observe the clinical efficacy and radiographic outcomes of manipulative reduction combined with small splint fixation in the treatment of distal radius fractures. MethodsThe clinical data of 1051 patients with distal radius fractures were retrospectively collected from five hospitals included in the Jiangsu Diagnosis and Treatment Data Platform for Traditional Chinese Medicine（TCM） Dominant Diseases. Propensity score matching at a 1∶4 ratio was applied， resulting in 580 cases selected for final analysis， which comprised 448 patients in the TCM group（manipulative reduction plus small splint fixation） and 132 in the surgical treatment group（open reduction and internal fixation）. Each group was further stratified into type A， B， and C subgroups based on AO fracture classification. Radiographic indicators including palmar tilt， radial inclination， and radial height were compared between groups before treatment and 1 day， 1 week， and 4-6 weeks after treatment， and pain visual analog scale（VAS） scores before treatment and 1 week and 4-6 weeks after treatment were also compared. Wrist joint function was assessed 12 weeks after treatment， using the Dienst wrist function score and the Gartland and Werley（G-W） wrist function score. Additionally， the radiographic indicators at different timepoints and the 12-week wrist function levels were compared between groups across different fracture types. ResultsNo statistically significant difference was observed in radiographic indicators and VAS scores at all timepoints before and after treatment， as well as wrist joint function grades assessed by the Dienst score and the G-W score at 12 weeks after treatment （P＞0.05）. Compared to those before treatment， both groups showed increased palmar tilt， radial inclination， and radial height 1 week and 4-6 weeks after treatment， and decreased VAS scores （P＜0.05）. Compared to those 1 week after treatment， both groups showed a decrease in palmar tilt， an increase in radial inclination and radial height， and a reduction in VAS score 4-6 weeks after treatment（P＜0.05）. In type A and B subgroups， the surgical treatment group had a higher radial inclination than the TCM group 4-6 weeks after treatment， while in the type C subgroup， a higher radial height was shown in the surgical treatment group than in the TCM group 4-6 weeks after treatment（P＜0.05）. In type C subgroup， there was significant difference between groups in the wrist joint function by G-W scores 12 weeks after treatment（P＜0.05）. ConclusionManipulative reduction combined with small splint fixation can maintain fracture alignment and alleviate pain in treating distal radius fractures， which achieves therapeutic outcomes comparable to surgical treatment. It is particularly suitable for type A and B fractures and can be considered an effective treatment option for distal radius fractures.

ObjectiveTo establish and evaluate different disease-syndrome combination mice models of knee osteoarthritis （KOA） with cold-dampness obstruction syndrome， and to identify the optimal modeling method. MethodsEighty mice were randomly divided into a control group， a treadmill plus climate chamber group， an anterior cruciate ligament transection （ACLT） plus climate chamber group， an ACLT group， a destabilization of the medial meniscus （DMM） plus climate chamber group， a DMM group， an intra-articular injection plus climate chamber group， and an intra-articular injection group， with 10 mice in each group. Mice in the ACLT group underwent surgical transection of the knee anterior cruciate ligament to establish the model， while those in the DMM underwent surgical transection of the medial meniscal tibial ligament of the knee， and those in the intra-articular injection group were modeled by an intra-articular injection of 50 μl of normal saline containing 1mg of monosodium iodoacetate （MIA） into the medial side of the patellar ligament. Mice in the ACLT plus climate chamber， DMM plus climate chamber， and intra-articular injection plus climate chamber groups were placed in an artificial climate chamber （relative humidity 60%， temperature 4 ℃， wind speed 6 m/s） simultaneously with aforementioned interventions， once daily for 2 h each time， for 14 consecutive days. Mice in the control group underwent sham surgery， involving only the incision of the skin and subcutaneous tissue at the knee joint to expose the articular cavity， followed by layer-by-layer suturing. Mice in the treadmill plus climate chamber group were placed on an animal treadmill starting on the 4th day after the sham operation， undergoing high-intensity treadmill exercise at a speed of 20 m/min， an inclination of 5°， for 30min per session， 5 times per week for 28 consecutive days， while being housed in the artificial climate chamber. Cold pain thresholds of the mice in each group were compared using the cold plate test and the acetone low-temperature test before and after modeling. Following modeling， knee joint pathological changes were observed using HE and Safranin O-Fast Green staining， and quantified using Mankin and Osteoarthritis Research Society International （OARSI） scores. Serum levels of tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β） were measured by ELISA. Protein and mRNA expression levels of pain-related markers， including calcitonin gene-related peptide （CGRP）， protein gene product 9.5 （PGP9.5）， and cellular proto-oncogene Fos （c-Fos）， and the cold hyperalgesia-related markers including transient receptor potential ankyrin 1 （TRPA1） and transient receptor potential melastatin 8 （TRPM8） in the dorsal root ganglion （DRG） tissues were detected by Western Blot and qPCR. TRPA1 and TRPM8 fluorescent intensity in the DRG was detected by immunofluorescence assay. ResultsCompared to the control group， the remaining groups showed decreased cold pain thresholds in the cold plate tese， increased cold pain thresholds in the acetone low-temperature test， elevated Mankin and OARSI scores， and increased serum TNF-α and IL-1β levels， upregulated protein and mRNA expression levels of CGRP， PGP9.5， c-Fos， TRPA1， and TRPM8 in the DRG， and increased immunofluorescence intensities of TRPA1 and TRPM8 in the DRG tissue （P＜0.05 or P＜0.01）， along with severe pathological damage and cartilage degeneration in the knee joints. Compared to the ACLT， DMM， and intra-articular injection groups， the ACLT plus climate chamber， DMM plus climate chamber， and intra-articular injection plus climate chamber groups exhibited more significant changes in all the aforementioned indicators （P＜0.01）. Furthermore， changes in the aforementioned indicators were more pronounced in the ACLT plus climate chamber group compared to the Treadmill plus climate chamber group， DMM plus climate chamber and intra-articular injection plus climate chamber group （P＜0.01）， exhibiting the most severe degree of pathological damage and cartilage degeneration. ConclusionThe combination of an artificial climate chamber can successfully establish a disease-syndrome combined animal model of KOA with cold-damp obstruction syndrome， with the ACLT combined with the artificial climate chamber being the optimal modeling approach.

ObjectiveTo establish and evaluate different disease-syndrome combination mice models of knee osteoarthritis （KOA） with cold-dampness obstruction syndrome， and to identify the optimal modeling method. MethodsEighty mice were randomly divided into a control group， a treadmill plus climate chamber group， an anterior cruciate ligament transection （ACLT） plus climate chamber group， an ACLT group， a destabilization of the medial meniscus （DMM） plus climate chamber group， a DMM group， an intra-articular injection plus climate chamber group， and an intra-articular injection group， with 10 mice in each group. Mice in the ACLT group underwent surgical transection of the knee anterior cruciate ligament to establish the model， while those in the DMM underwent surgical transection of the medial meniscal tibial ligament of the knee， and those in the intra-articular injection group were modeled by an intra-articular injection of 50 μl of normal saline containing 1mg of monosodium iodoacetate （MIA） into the medial side of the patellar ligament. Mice in the ACLT plus climate chamber， DMM plus climate chamber， and intra-articular injection plus climate chamber groups were placed in an artificial climate chamber （relative humidity 60%， temperature 4 ℃， wind speed 6 m/s） simultaneously with aforementioned interventions， once daily for 2 h each time， for 14 consecutive days. Mice in the control group underwent sham surgery， involving only the incision of the skin and subcutaneous tissue at the knee joint to expose the articular cavity， followed by layer-by-layer suturing. Mice in the treadmill plus climate chamber group were placed on an animal treadmill starting on the 4th day after the sham operation， undergoing high-intensity treadmill exercise at a speed of 20 m/min， an inclination of 5°， for 30min per session， 5 times per week for 28 consecutive days， while being housed in the artificial climate chamber. Cold pain thresholds of the mice in each group were compared using the cold plate test and the acetone low-temperature test before and after modeling. Following modeling， knee joint pathological changes were observed using HE and Safranin O-Fast Green staining， and quantified using Mankin and Osteoarthritis Research Society International （OARSI） scores. Serum levels of tumor necrosis factor-α （TNF-α） and interleukin-1β （IL-1β） were measured by ELISA. Protein and mRNA expression levels of pain-related markers， including calcitonin gene-related peptide （CGRP）， protein gene product 9.5 （PGP9.5）， and cellular proto-oncogene Fos （c-Fos）， and the cold hyperalgesia-related markers including transient receptor potential ankyrin 1 （TRPA1） and transient receptor potential melastatin 8 （TRPM8） in the dorsal root ganglion （DRG） tissues were detected by Western Blot and qPCR. TRPA1 and TRPM8 fluorescent intensity in the DRG was detected by immunofluorescence assay. ResultsCompared to the control group， the remaining groups showed decreased cold pain thresholds in the cold plate tese， increased cold pain thresholds in the acetone low-temperature test， elevated Mankin and OARSI scores， and increased serum TNF-α and IL-1β levels， upregulated protein and mRNA expression levels of CGRP， PGP9.5， c-Fos， TRPA1， and TRPM8 in the DRG， and increased immunofluorescence intensities of TRPA1 and TRPM8 in the DRG tissue （P＜0.05 or P＜0.01）， along with severe pathological damage and cartilage degeneration in the knee joints. Compared to the ACLT， DMM， and intra-articular injection groups， the ACLT plus climate chamber， DMM plus climate chamber， and intra-articular injection plus climate chamber groups exhibited more significant changes in all the aforementioned indicators （P＜0.01）. Furthermore， changes in the aforementioned indicators were more pronounced in the ACLT plus climate chamber group compared to the Treadmill plus climate chamber group， DMM plus climate chamber and intra-articular injection plus climate chamber group （P＜0.01）， exhibiting the most severe degree of pathological damage and cartilage degeneration. ConclusionThe combination of an artificial climate chamber can successfully establish a disease-syndrome combined animal model of KOA with cold-damp obstruction syndrome， with the ACLT combined with the artificial climate chamber being the optimal modeling approach.

AIM:This study aimed to investigate the inhibitory effects and potential mechanisms of cyasterone(CYA)on inflammation and apoptosis of chondrocytes in knee osteoarthritis(KOA).METHODS:A rat model of KOA was established through anterior cruciate ligament transection(ACLT).Rats were randomly divided into 5 groups(n=6 in each group):normal control(NC),ACLT,ACLT+CYA(10 mg/kg),ACLT+CYA+SR9009(BMAL1 inhibitor),and ACLT+CYA+LY294002(PI3K inhibitor).Pathological changes in cartilage were evaluated using hematoxylin-eosin(HE)and safranin O/fast green staining,graded according to the Osteoarthritis Research Society International(OARSI)system.Immunohistochemistry was employed to measure the expression levels of BMAL1,phosphorylated phosphati-dylinositol 3-kinase(p-PI3K),phosphorylated protein kinase B(p-AKT)and phosphorylated nuclear factor-κB(p-NF-κB)in cartilage.An in vitro KOA model was created by stimulating rat chondrocytes with interleukin-1β(IL-1β).Cell vi-ability was assessed using the CCK-8 assay,while enzyme-linked immunosorbent assay(ELISA)was used to quantify pro-inflammatory cytokines(IL-6,IL-1β and TNF-α).Apoptosis was analyzed via flow cytometry,and the protein expression levels of BMAL1,PI3K,p-PI3K,AKT,p-AKT,NF-κB and p-NF-κB were evaluated using Western blot.RESULTS:In vivo,the rats in ACLT group exhibited significant chondrocyte degradation and lacunae formation compared with NC group,confirming the successful establishment of the KOA model.The rats in ACLT+CYA,ACLT+CYA+SR9009 and ACLT+CYA+LY294002 groups showed improved cartilage integrity compared with ACLT group,with reduced OARSI scores(P<0.05),increased BMAL1 expression(P<0.05),and decreased levels of p-PI3K,p-AKT and p-NF-κB(P<0.05).In vitro,the chondrocytes in IL-1β+CYA,IL-1β+CYA+SR9009 and IL-1β+CYA+LY294002 groups exhibited lower levels of IL-6,IL-1β and TNF-α(P<0.05),decreased apoptosis rates(P<0.01),increased BMAL1 protein ex-pression(P<0.05),and reduced p-PI3K/PI3K,p-AKT/AKT and p-NF-κB/NF-κB ratios(P<0.05),compared with IL-1β group.CONCLUSION:Cyasterone alleviates chondrocyte inflammation and apoptosis in KOA by activating BMAL1,which subsequently inhibits the phosphorylation of PI3K/AKT/NF-κB signaling pathway.

OBJECTIVE To explore the effectiveness and possible mechanism of Shangke Lengtong Patch in treating knee osteo-arthritis with cold-dampness arthralgia obstruction.METHODS A total of 70 patients who met the inclusion criteria of knee osteoar-thritis with cold-dampness arthralgia obstruction in the Orthopedics Department of Affiliated Hospital of Nanjing University of Chinese Medicine from November to December 2024 were randomly divided into an experimental group and a control group,with 35 cases in each group.During the treatment,1 case dropped out of the experimental group,3 cases dropped out of the control group,and 1 case was discontinued.The experimental group was treated with Shangke Lengtong Patch,and the control group was treated with Compound Nanxing Zhitong Ointment.The WOMAC scores and TCM syndrome scores of the two groups before and after treatment were compared to comprehensively evaluate the clinical efficacy.The changes in the expression levels of CGRP,substance P,HMGB1,IL-1β,CX-CL12,and CXCR4 in the serum of the two groups were detected by ELISA.RESULTS After 3,7,and 14 d of treatment,the WOMAC scores and TCM syndrome scores of the two groups were significantly reduced(P<0.05,P<0.01),and the score of aggrava-ted cold in the experimental group was better than that in the control group at 7 d of treatment(P<0.05);after 14 d of treatment,the expression levels of CGRP,substance P,HMGB1,IL-1β,CXCL12,and CXCR4 in the serum of the two groups were significantly re-duced(P<0.05),and there was no statistical difference between the two groups.CONCLUSION Shangke Lengtong Patch can sig-nificantly relieve the pain symptoms of knee osteoarthritis patients with cold-dampness arthralgia obstruction and improve the joint func-tion of patients.It may improve synovial inflammation by inhibiting the HMGB1/CXCL12/CXCR4 pathway,thereby exerting a thera-peutic effect.

AIM:This study aimed to investigate the inhibitory effects and potential mechanisms of cyasterone(CYA)on inflammation and apoptosis of chondrocytes in knee osteoarthritis(KOA).METHODS:A rat model of KOA was established through anterior cruciate ligament transection(ACLT).Rats were randomly divided into 5 groups(n=6 in each group):normal control(NC),ACLT,ACLT+CYA(10 mg/kg),ACLT+CYA+SR9009(BMAL1 inhibitor),and ACLT+CYA+LY294002(PI3K inhibitor).Pathological changes in cartilage were evaluated using hematoxylin-eosin(HE)and safranin O/fast green staining,graded according to the Osteoarthritis Research Society International(OARSI)system.Immunohistochemistry was employed to measure the expression levels of BMAL1,phosphorylated phosphati-dylinositol 3-kinase(p-PI3K),phosphorylated protein kinase B(p-AKT)and phosphorylated nuclear factor-κB(p-NF-κB)in cartilage.An in vitro KOA model was created by stimulating rat chondrocytes with interleukin-1β(IL-1β).Cell vi-ability was assessed using the CCK-8 assay,while enzyme-linked immunosorbent assay(ELISA)was used to quantify pro-inflammatory cytokines(IL-6,IL-1β and TNF-α).Apoptosis was analyzed via flow cytometry,and the protein expression levels of BMAL1,PI3K,p-PI3K,AKT,p-AKT,NF-κB and p-NF-κB were evaluated using Western blot.RESULTS:In vivo,the rats in ACLT group exhibited significant chondrocyte degradation and lacunae formation compared with NC group,confirming the successful establishment of the KOA model.The rats in ACLT+CYA,ACLT+CYA+SR9009 and ACLT+CYA+LY294002 groups showed improved cartilage integrity compared with ACLT group,with reduced OARSI scores(P<0.05),increased BMAL1 expression(P<0.05),and decreased levels of p-PI3K,p-AKT and p-NF-κB(P<0.05).In vitro,the chondrocytes in IL-1β+CYA,IL-1β+CYA+SR9009 and IL-1β+CYA+LY294002 groups exhibited lower levels of IL-6,IL-1β and TNF-α(P<0.05),decreased apoptosis rates(P<0.01),increased BMAL1 protein ex-pression(P<0.05),and reduced p-PI3K/PI3K,p-AKT/AKT and p-NF-κB/NF-κB ratios(P<0.05),compared with IL-1β group.CONCLUSION:Cyasterone alleviates chondrocyte inflammation and apoptosis in KOA by activating BMAL1,which subsequently inhibits the phosphorylation of PI3K/AKT/NF-κB signaling pathway.

OBJECTIVE To explore the effectiveness and possible mechanism of Shangke Lengtong Patch in treating knee osteo-arthritis with cold-dampness arthralgia obstruction.METHODS A total of 70 patients who met the inclusion criteria of knee osteoar-thritis with cold-dampness arthralgia obstruction in the Orthopedics Department of Affiliated Hospital of Nanjing University of Chinese Medicine from November to December 2024 were randomly divided into an experimental group and a control group,with 35 cases in each group.During the treatment,1 case dropped out of the experimental group,3 cases dropped out of the control group,and 1 case was discontinued.The experimental group was treated with Shangke Lengtong Patch,and the control group was treated with Compound Nanxing Zhitong Ointment.The WOMAC scores and TCM syndrome scores of the two groups before and after treatment were compared to comprehensively evaluate the clinical efficacy.The changes in the expression levels of CGRP,substance P,HMGB1,IL-1β,CX-CL12,and CXCR4 in the serum of the two groups were detected by ELISA.RESULTS After 3,7,and 14 d of treatment,the WOMAC scores and TCM syndrome scores of the two groups were significantly reduced(P<0.05,P<0.01),and the score of aggrava-ted cold in the experimental group was better than that in the control group at 7 d of treatment(P<0.05);after 14 d of treatment,the expression levels of CGRP,substance P,HMGB1,IL-1β,CXCL12,and CXCR4 in the serum of the two groups were significantly re-duced(P<0.05),and there was no statistical difference between the two groups.CONCLUSION Shangke Lengtong Patch can sig-nificantly relieve the pain symptoms of knee osteoarthritis patients with cold-dampness arthralgia obstruction and improve the joint func-tion of patients.It may improve synovial inflammation by inhibiting the HMGB1/CXCL12/CXCR4 pathway,thereby exerting a thera-peutic effect.

ObjectiveTo observe the effects of Xibining （XBN） and adipose stem cell exosome （ADSC-Exos） in the cases of separate or joint application on cartilage degeneration and mitochondrial autophagy and explore its mechanism of action to improve knee osteoarthritis （KOA）. MethodSD rats were divided into a sham operation group （sham group）， a model group， an ADSC-Exos group （Exos group）， an XBN group， and an ADSC-Exos+XBN group （Exos+XBN group）. KOA model was established by using anterior cruciate ligament transection （ACLT）. The pain sensitivity status of rats was evaluated， and the degeneration degree of the knee joint and cartilage tissue was detected by Micro-CT and pathological staining. The expression of p62 and LC3B was observed by immunofluorescence， and the serum levels of TNF-α， IL-1β， IL-6， and IL-15 in rats were detected by ELISA. The Western blot was used to detect the protein expression levels of MMP-3， MMP-13， ADAMTS5， ColⅡ， TIMP， ACAN， PINK1， Parkin， p62， and LC3A/B. ResultCompared with the sham group， rats in the model group showed decreased cold-stimulated foot-shrinkage thresholds and mechanical pain sensitivity thresholds， varying degrees of abrasion and loss of cartilage tissue， degeneration of cartilage tissue， elevated serum IL-1β， IL-6， IL-15， and TNF-α levels （P<0.01）， and increased protein expression of MMP-3， MMP-13， and ADAMTS5 in cartilage tissue. In addition， the protein expression of ColⅡ， TIMP1， and ACAN was decreased （P<0.01）. Compared with the model group， rats in each treatment group showed higher cold-stimulated foot-shrinkage thresholds and mechanical pain sensitivity thresholds， reduced cartilage tissue degeneration， lower serum levels of IL-1β， IL-6， IL-15， and TNF-α （P<0.05，P<0.01）， decreased protein expression of MMP-3， MMP-13， and ADAMTS5， and higher protein expression of Cold， TIMP1， and ACAN in cartilage tissue （P<0.05，P<0.01）. Moreover， the changes were the most obvious in the Exos+XBN group. ConclusionBoth ADSCs-Exos and XBN can increase the level of mitochondrial autophagy in chondrocytes and delay cartilage tissue degeneration by promoting the expression of the PINK1/Parkin signaling pathway， and the combination of the two can enhance the therapeutic effect.

ObjectiveTo retrospectively analyze the clinical efficacy of Xibining Ⅱ prescription in the treatment of knee osteoarthritis with cold-dampness blockage syndrome by oral medication and to explore the influencing factors of endpoint events. MethodA real-world retrospective cohort design was adopted， and medical records of knee osteoarthritis patients with cold-dampness blockage syndrome treated with oral medication from the orthopedics outpatient department of Jiangsu Province Hospital of Chinese Medicine were collected. All patients received conventional Western medicine treatment and were divided into non-exposure group （573 cases） and exposure group （427 cases） according to whether or not they received treatment with Xibining Ⅱ prescription. Descriptive analysis of the baseline data of the 1 000 screened cases was performed using IBM SPSS 27.0. According to the baseline data， 334 pairs were matched using the propensity score matching method， resulting in a total of 668 cases in both groups. The changes in visual analogous scale （VAS）， Western Ontario and McMaster Universities Osteoarthritis Index （WOMAC） total score， Japanese Knee Osteoarthritis Measure （JKOM） score， and traditional Chinese medicine （TCM） syndrome score before treatment and at 2， 6， 12 weeks after treatment， as well as the incidence of adverse reactions， were compared between the two groups. A multivariate logistic regression analysis was conducted to analyze the influencing factors of endpoint events， with clinical cure judged based on the improvement rate of WOMAC total score before and after treatment. ResultAfter 12 weeks of treatment， compared to the results before treatment， the VAS， WOMAC total score， JKOM score， and TCM syndrome score of patients in both groups significantly decreased （P<0.01）. Compared to the non-exposure group， the exposure group showed a more significant reduction in VAS， WOMAC total score， JKOM score， and TCM syndrome score （P<0.01）. After 12 weeks of treatment， the clinical cure rate and significant efficiency were higher in the exposure group than in the non-exposure group （P<0.05）. Compared to the results before treatment within each group， VAS， WOMAC pain， stiffness， function scores， JKOM score， and TCM syndrome score significantly decreased at 2， 6， 12 weeks after treatment in both groups （P<0.01）. Compared to the non-exposure group at the same time points， the exposure group showed a reduction in VAS at 2， 12 weeks， WOMAC pain at 6， 12 weeks， and function scores at 12 weeks （P<0.05， P<0.01）. The JKOM score decreased at 6， 12 weeks， and the TCM syndrome score significantly decreased at 2， 6， 12 weeks in the exposure group （P<0.05， P<0.01）. Multivariate logistic regression analysis at 12 weeks showed that factors affecting clinical cure included the course of disease， history of alcohol consumption， hypertension， coronary heart disease， and the use of Xibining Ⅱ prescription （P<0.05， P<0.01）. Compared to the non-exposure group at the same time points， the incidence of epigastric discomfort in the exposure group was lower at 2， 12 weeks （P<0.01）， the incidence of diarrhea and vomiting was slightly higher than that in the non-exposure group， but the difference was not statistically significant. ConclusionThe clinical application of Xibining Ⅱ prescription combined with conventional Western medicine treatment in the treatment of knee osteoarthritis with cold-dampness blockage syndrome is more effective than conventional Western medicine treatment alone. It can significantly reduce VAS， WOMAC total score， JKOM score， and TCM syndrome score， with more pronounced long-term effects and a low incidence of adverse reactions.

OBJECTIVES: To investigate the effect of nuclear protein (Nupr) 1 on the pathological progression of osteoarthritis and its relationship with ferroptosis of chondrocytes. METHODS: Chondrocytes from mouse knees were divided into small interfering RNA (siRNA) control group, small interfering RNA targeting Nupr1 (siNupr1) group, siRNA control+IL-1β group (siRNA control interference for 24 h followed by 10 ng/mL IL-1β) and siNupr1+IL-1β group (siNupr1 interference for 24 h followed by 10 ng/mL IL-1β). The protein and mRNA expressions of Nupr1 were detected by Western blotting and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Cell proliferation viabilities were measured using the cell counting kit-8 method. The levels of ferrous ions were detected by FerroOrange staining. Lipid peroxidation levels were detected by C11-BODIPY-591 fluorescence imaging. The contents of malondialdehyde (MDA) and glutathione (GSH) were detected by enzyme-linked immunosorbent assay. The protein expressions of acyl-CoA synthetase long-chain family (ACSL) 4, P53, glutathione peroxidase (GPX) 4 and solute carrier family 7 member 11 gene (SLC7A11) were detected by Western blotting. The osteoarthritis model was constructed by destabilization of the medial meniscus (DMM) surgery in 7-week-old male C57BL/6J mice. The mice were randomly divided into four groups with 10 animals in each group: sham surgery (Sham)+adeno-associated virus serotype 5 (AAV5)-short hairpin RNA (shRNA) control group, Sham+AAV5-shRNA control targeting Nupr1 (shNupr1) group, DMM+AAV5-shRNA control group, and DMM+AAV5-shNupr1 group. Hematoxylin and eosin staining and Safranin O-Fast Green staining were used to observe the morphological changes in cartilage tissue. The Osteoarthritis Research Society International (OARSI) osteoarthritis cartilage histopathology assessment system was used to evaluate the degree of cartilage degeneration in mice. The mRNA expressions of matrix metallopeptidase (MMP) 13, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 5, cyclooxy-genase (COX) 2, and GPX4 were detected by qRT-PCR. RESULTS: In vitro experiments showed that knocking down Nupr1 alleviated the decrease of chondrocyte proliferation activity induced by IL-1β, reduced iron accumulation in mouse chondrocytes, lowered lipid peroxidation, downregulated ACSL4 and P53 protein expression and upregulated GPX4 and SLC7A11 protein expression (all P<0.01), thereby inhibiting ferroptosis in mouse chondrocytes. Meanwhile, in vivo animal experiments demonstrated that knocking down Nupr1 delayed the degeneration of articular cartilage in osteoarthritis mice, improved the OARSI score, slowed down the degradation of the extracellular matrix in osteoarthritis cartilage, and reduced the expression of the key ferroptosis regulator GPX4 (all P<0.01). CONCLUSIONS Knockdown of Nupr1 can delay the pathological progression of osteoarthritis through inhibiting ferroptosis in mouse chondrocytes.
Animals ; Ferroptosis ; Mice ; Chondrocytes/metabolism* ; Osteoarthritis/pathology* ; RNA, Small Interfering/genetics* ; Basic Helix-Loop-Helix Transcription Factors/genetics* ; Interleukin-1beta/metabolism* ; Phospholipid Hydroperoxide Glutathione Peroxidase/genetics* ; Coenzyme A Ligases/genetics* ; Tumor Suppressor Protein p53/metabolism* ; Mice, Inbred C57BL ; DNA-Binding Proteins ; Neoplasm Proteins ; Amino Acid Transport System y+ ; Nuclear Receptor Subfamily 1, Group D, Member 1