ObjectiveTo evaluate the therapeutic effects of Huanglian Jiedutang on cerebral infarction injury in a mouse model of middle cerebral artery occlusion （MCAO） and to explore its mechanism of action on oligodendrocytes， particularly its potential in myelin repair. MethodsMultiple experimental approaches were used to evaluate cerebral ischemic injury and the effects of drug intervention. Laser speckle imaging was used to detect changes in cerebral blood flow， 2，3，5-Triphenyltetrazolium chloride （TTC） staining was used to measure infarct volume， and neurological function was scored according to the Zea-Longa criteria. Brain tissues were routinely embedded in paraffin and subjected to HE and Nissl staining to observe tissue structure and neuronal damage. Animals were divided into a sham group （n=24）， model group （n=24）， Huanglian Jiedutang group （n=24）， and Ginkgo biloba extract （GBE） group （n=18）. After 1 week of acclimatization， intragastric administration was initiated. The sham and model groups received normal saline， the Huanglian Jiedutang group was administered 1.82 g·kg^-1， and the GBE group was administered 0.432 g·kg^-1 after preparation as a 2.16 g·L^-1 solution. All groups were treated for 5 consecutive days at a dose of 0.2 mL·（10 g）^-¹·d^-¹. The MCAO model was established after the final administration on day 6. Single-cell RNA sequencing was used to analyze brain tissue cellular composition and changes in oligodendrocyte subpopulations. Distinct subpopulations were identified by Uniform manifold approximation and projection （UMAP） dimensionality reduction and unsupervised clustering， and marker gene expression was analyzed. Pathway enrichment and causal inference were further performed using IPA. Finally， real-time quantitative PCR was used to verify mRNA expression changes of myelin-related genes. ResultsCompared with the sham group， the model group showed significantly increased neurological function scores （P<0.01）， significantly impaired blood flow （P<0.01）， significantly enlarged cerebral infarct area （P<0.01）， and pathological changes including disordered cortical structural arrangement， aggravated cytoplasmic vacuolization， and increased Nissl bodies. Compared with the model group， the Huanglian Jiedutang and GBE groups showed significantly decreased neurological function scores （P<0.01）， markedly restored blood flow levels （P<0.01）， significantly reduced cerebral infarct area （P<0.01）， and improvement in cortical structural disorder， alleviation of cytoplasmic vacuolization， and a reduction in Nissl bodies. Single-cell data showed that a myelin-associated oligodendrocyte （Mye-OL） subpopulation existed among oligodendrocytes， which was closely related to myelin generation. Compared with the sham group， the number of Mye-OL cells decreased in the model group. Compared with the model group， the number of Mye-OL cells increased in the Huanglian Jiedutang group. This subpopulation promoted the expression of myelin-related genes， including MOG， MBP， and MAG， via transcription factors such as OLIG1， OLIG2， NKX2-2， and SOX10， thereby regulating myelin generation， restoring cognition， and exerting therapeutic effects on acute cerebral infarction. Compared with the sham group， the mRNA expression levels of OLIG1， OLIG2， NKX2-2， and SOX10 were significantly downregulated in the model group （P<0.01）， and the mRNA expression levels of myelin-related genes， including MOG， MBP， and MAG， were also significantly downregulated （P<0.01）. In contrast， compared with the model group， the Huanglian Jiedutang and GBE groups showed significantly upregulated mRNA expression levels of OLIG1， OLIG2， NKX2-2， and SOX10 （P<0.01）， and significantly upregulated mRNA expression levels of myelin-related genes， including MOG， MBP， and MAG （P<0.01）. ConclusionHuanglian Jiedutang exerts therapeutic effects on acute cerebral infarction by regulating the OLIG1/2-NKX2-2-SOX10 signaling pathway to promote myelin generation by Mye-OL cells.

ObjectiveTo evaluate the therapeutic effects of Huanglian Jiedutang on cerebral infarction injury in a mouse model of middle cerebral artery occlusion （MCAO） and to explore its mechanism of action on oligodendrocytes， particularly its potential in myelin repair. MethodsMultiple experimental approaches were used to evaluate cerebral ischemic injury and the effects of drug intervention. Laser speckle imaging was used to detect changes in cerebral blood flow， 2，3，5-Triphenyltetrazolium chloride （TTC） staining was used to measure infarct volume， and neurological function was scored according to the Zea-Longa criteria. Brain tissues were routinely embedded in paraffin and subjected to HE and Nissl staining to observe tissue structure and neuronal damage. Animals were divided into a sham group （n=24）， model group （n=24）， Huanglian Jiedutang group （n=24）， and Ginkgo biloba extract （GBE） group （n=18）. After 1 week of acclimatization， intragastric administration was initiated. The sham and model groups received normal saline， the Huanglian Jiedutang group was administered 1.82 g·kg^-1， and the GBE group was administered 0.432 g·kg^-1 after preparation as a 2.16 g·L^-1 solution. All groups were treated for 5 consecutive days at a dose of 0.2 mL·（10 g）^-¹·d^-¹. The MCAO model was established after the final administration on day 6. Single-cell RNA sequencing was used to analyze brain tissue cellular composition and changes in oligodendrocyte subpopulations. Distinct subpopulations were identified by Uniform manifold approximation and projection （UMAP） dimensionality reduction and unsupervised clustering， and marker gene expression was analyzed. Pathway enrichment and causal inference were further performed using IPA. Finally， real-time quantitative PCR was used to verify mRNA expression changes of myelin-related genes. ResultsCompared with the sham group， the model group showed significantly increased neurological function scores （P<0.01）， significantly impaired blood flow （P<0.01）， significantly enlarged cerebral infarct area （P<0.01）， and pathological changes including disordered cortical structural arrangement， aggravated cytoplasmic vacuolization， and increased Nissl bodies. Compared with the model group， the Huanglian Jiedutang and GBE groups showed significantly decreased neurological function scores （P<0.01）， markedly restored blood flow levels （P<0.01）， significantly reduced cerebral infarct area （P<0.01）， and improvement in cortical structural disorder， alleviation of cytoplasmic vacuolization， and a reduction in Nissl bodies. Single-cell data showed that a myelin-associated oligodendrocyte （Mye-OL） subpopulation existed among oligodendrocytes， which was closely related to myelin generation. Compared with the sham group， the number of Mye-OL cells decreased in the model group. Compared with the model group， the number of Mye-OL cells increased in the Huanglian Jiedutang group. This subpopulation promoted the expression of myelin-related genes， including MOG， MBP， and MAG， via transcription factors such as OLIG1， OLIG2， NKX2-2， and SOX10， thereby regulating myelin generation， restoring cognition， and exerting therapeutic effects on acute cerebral infarction. Compared with the sham group， the mRNA expression levels of OLIG1， OLIG2， NKX2-2， and SOX10 were significantly downregulated in the model group （P<0.01）， and the mRNA expression levels of myelin-related genes， including MOG， MBP， and MAG， were also significantly downregulated （P<0.01）. In contrast， compared with the model group， the Huanglian Jiedutang and GBE groups showed significantly upregulated mRNA expression levels of OLIG1， OLIG2， NKX2-2， and SOX10 （P<0.01）， and significantly upregulated mRNA expression levels of myelin-related genes， including MOG， MBP， and MAG （P<0.01）. ConclusionHuanglian Jiedutang exerts therapeutic effects on acute cerebral infarction by regulating the OLIG1/2-NKX2-2-SOX10 signaling pathway to promote myelin generation by Mye-OL cells.

Objective To elucidate the changes in the gut microbiota and molecular mechanism of huaier in enhancing the efficacy of oxaliplatin (OXA) chemotherapy in gastric cancer (GC). Methods The effects of huaier on the gut microbiota structure and intestinal barrier function in MKN45-bearing mice were analyzed by using 16S rRNA sequencing, RT-qPCR, and IHC. UPLC-MS and network pharmacology, as well as in vivo experimental approaches, were employed to investigate the key bioactive constituents of huaier systematically and elucidate the underlying mechanisms by which huaier exerts therapeutic effects against GC. The expression of the PI3K/AKT/SREBP pathway was detected in cancer cells and tissues via Western blot analysis. The safety profile of huaier combined with OXA was verified through serum biochemistry and HE-stained tissue section analyses. Results Huaier inhibited the PI3K/AKT/SREBP pathway by increasing the abundance of Akkermansia muciniphila, reduced lipid droplet deposition, and ultimately enhanced the sensitivity to OXA in the treatment of GC. Conclusion This study demonstrates the value of huaier in gastric cancer treatment by enhancing chemosensitivity and provides novel insights into its systemic therapeutic effects through molecular mechanisms and gut microbiota modulation.

Objective Objective To analyze the potential spatial factors affecting the genetic differentiation of Oncomelania hupensis robertsoni in Yunnan Province. Methods A total of 13 administrative villages were selected from schistosomiasis-endemic areas of Yunnan Province as O. hupensis snail sampling sites. At least 200 snails were collected in each site, and the spatial variable data of each site were recorded, including longitude, latitude and altitude. Thirty active and Schistosoma japonicum uninfected O. hupensis snails were selected from each sampling site by means of the crawling method and the cercarial shedding method. Genomic DNA was extracted from O. hupensis snails. Following PCR amplification, purification of PCR amplification products and sequencing, the gene sequences of O. hupensis snail samples were spliced and edited using the DNAstar software and the NCBI database to yield the complete mitochondrial sequences of O. hupensis snails at each sampling site, and the mitochondrial genetic distance matrix of O. hupensis robertsoni was calculated at each sampling site. The geographical coordinates of each sampling site were marked using the software ArcGIS 10.2, and the straight-line geographical distance between each sampling site was calculated. The altitude difference, longitude difference and latitude difference between each sampling site were calculated using the Excel software, and the correlation between the mitochondrial genetic distance matrix of O. hupensis robertsoni and each spatial variable matrix was examined by using the Mantel test at 13 sampling sites in Yunnan Province. Results Among the 13 O. hupensis snail sampling sites in Yunnan Province, the largest mitochondrial genetic distance of O. hupensis robertsoni snail populations was seen between Anding Village, Nanjian Yi Autonomous County and Caizhuang Village, Midu County (26.244 2), and the largest geographical distance was seen between Dongyuan Village, Gucheng District and Cangling Village, Chuxiong County (272.64 km). The highest altitude difference was seen between Anding Village, Nanjian Yi Autonomous County and Dongyuan Village, Gucheng District (1 086.10 m), and the largest longitude difference was found between Qiandian Village, Eryuan County and Cangling Village, Chuxiong County (1.86°), while the largest latitude difference was measured between Leqiu Village, Nanjian Yi Autonomous County and Dongyuan Village, Gucheng District (1.81°). In addition, the mitochondrial genetic distance of O. hupensis robertsoni snail populations was positively correlated with altitude at 13 snail sampling sites in Yunnan Province (r = 0.542 8, P < 0.001), and showed no significant correlations with geographical distance (r = 0.093 4, P > 0.05), longitude (r = −0.199 5, P > 0.05) or latitude (r = 0.205 7, P > 0.05). Conclusion Altitude may be a potential spatial factor affecting the genetic differentiation of O. hupensis robertsoni in Yunnan Province.

BACKGROUND:Studies have shown that rheumatoid arthritis and osteoporosis are positively correlated,but the causal relationship and related mechanisms have not yet been confirmed.With the cross-fertilization of computer science and life sciences,Mendelian randomization and bioinformatics analyses based on genome-wide association study(GWAS)and transcriptome sequencing data can assess the causal relationship between two diseases,explore the related mechanisms,and mine the therapeutic targets,which will be beneficial to the precision treatment of rheumatoid arthritis combined with osteoporosis.OBJECTIVE:To explore the causal relationship between rheumatoid arthritis and osteoporosis using two-sample Mendelian randomization and to mine potential co-morbid targets and potential targeted drugs through summary-data-based Mendelian randomization and bioinformatics analyses,aiming to provide theoretical basis for mechanism exploration and precision treatment in the field of rheumatoid arthritis combined with osteoporosis.METHODS:(1)Firstly,GWAS data of rheumatoid arthritis,osteoporosis,and cis-expression quantitative trait locus(cis-eQTL)in Asian and European populations were downloaded from the GWAS Catalog,IEU Open GWAS,FinnGen,and eQTLGen databases,and were used for two-sample Mendelian randomization analysis and summary-data-based Mendelian randomization analysis.(2)Transcriptome sequencing data of rheumatoid arthritis(GSE93272 and GSE15573)were downloaded from the GEO database for bioinformatics analysis.(3)Subsequently,forward and inverse Mendelian randomization analyses between rheumatoid arthritis and osteoporosis were performed,and inverse variance weighted was used as the main metric for the analyses,and the results were corroborated with MR Egger,simple mode,weighted median and weighted mode.(4)Then,the genes closely related to rheumatoid arthritis and osteoporosis were identified based on the summary-data-based Mendelian randomization analysis,and the co-disease targets of rheumatoid arthritis and osteoporosis were mined based on cross-analysis.Meanwhile,the biological functions of the co-morbid targets were verified based on bioinformatics analysis and cellular experiments.(5)In addition,a rheumatoid arthritis risk prediction nomogram was constructed based on DYRK2,and its prediction performance was verified by receiver operating characteristic curve,correction curve and decision curve.Finally,the target potential drugs were mined based on Enrichr database and molecular docking was performed.RESULTS AND CONCLUSION:(1)Forward Mendelian randomization analysis of rheumatoid arthritis and osteoporosis showed statistically significant results except for GCST90044540 and GCST90086118,and all other results indicated a significant causal relationship and positive correlation between rheumatoid arthritis and osteoporosis.(2)Inverse Mendelian randomization analysis suggested that no significant causal relationship was seen between osteoporosis and rheumatoid arthritis.(3)Summary-data-based Mendelian randomization analysis identified a total of 412 and 344 genes positively associated with rheumatoid arthritis and osteoporosis,and 421 and 347 genes negatively associated.Based on the cross-analysis,26 co-morbid genes were subsequently obtained.Among them,DYRK2 was a potential therapeutic target,and subsequent bioinformatics analysis and cellular experiments confirmed its important role in the progression of rheumatoid arthritis and osteoporosis.(4)Furthermore,the constructed nomogram has excellent predictive performance.Finally,four potential DYRK2-targeting drugs(undecanoic acid,metyrapone,JNJ-38877605,and ACA)were discovered and molecular docking also demonstrated reliable targeting ability.(5)In conclusion,based on GWAS data from Asian and European populations,we successfully demonstrated that rheumatoid arthritis and osteoporosis are causally related at the genetic level,DYRK2 is a potential therapeutic target,and four small molecules are potential target drugs.

BACKGROUND:Studies have shown that rheumatoid arthritis and osteoporosis are positively correlated,but the causal relationship and related mechanisms have not yet been confirmed.With the cross-fertilization of computer science and life sciences,Mendelian randomization and bioinformatics analyses based on genome-wide association study(GWAS)and transcriptome sequencing data can assess the causal relationship between two diseases,explore the related mechanisms,and mine the therapeutic targets,which will be beneficial to the precision treatment of rheumatoid arthritis combined with osteoporosis.OBJECTIVE:To explore the causal relationship between rheumatoid arthritis and osteoporosis using two-sample Mendelian randomization and to mine potential co-morbid targets and potential targeted drugs through summary-data-based Mendelian randomization and bioinformatics analyses,aiming to provide theoretical basis for mechanism exploration and precision treatment in the field of rheumatoid arthritis combined with osteoporosis.METHODS:(1)Firstly,GWAS data of rheumatoid arthritis,osteoporosis,and cis-expression quantitative trait locus(cis-eQTL)in Asian and European populations were downloaded from the GWAS Catalog,IEU Open GWAS,FinnGen,and eQTLGen databases,and were used for two-sample Mendelian randomization analysis and summary-data-based Mendelian randomization analysis.(2)Transcriptome sequencing data of rheumatoid arthritis(GSE93272 and GSE15573)were downloaded from the GEO database for bioinformatics analysis.(3)Subsequently,forward and inverse Mendelian randomization analyses between rheumatoid arthritis and osteoporosis were performed,and inverse variance weighted was used as the main metric for the analyses,and the results were corroborated with MR Egger,simple mode,weighted median and weighted mode.(4)Then,the genes closely related to rheumatoid arthritis and osteoporosis were identified based on the summary-data-based Mendelian randomization analysis,and the co-disease targets of rheumatoid arthritis and osteoporosis were mined based on cross-analysis.Meanwhile,the biological functions of the co-morbid targets were verified based on bioinformatics analysis and cellular experiments.(5)In addition,a rheumatoid arthritis risk prediction nomogram was constructed based on DYRK2,and its prediction performance was verified by receiver operating characteristic curve,correction curve and decision curve.Finally,the target potential drugs were mined based on Enrichr database and molecular docking was performed.RESULTS AND CONCLUSION:(1)Forward Mendelian randomization analysis of rheumatoid arthritis and osteoporosis showed statistically significant results except for GCST90044540 and GCST90086118,and all other results indicated a significant causal relationship and positive correlation between rheumatoid arthritis and osteoporosis.(2)Inverse Mendelian randomization analysis suggested that no significant causal relationship was seen between osteoporosis and rheumatoid arthritis.(3)Summary-data-based Mendelian randomization analysis identified a total of 412 and 344 genes positively associated with rheumatoid arthritis and osteoporosis,and 421 and 347 genes negatively associated.Based on the cross-analysis,26 co-morbid genes were subsequently obtained.Among them,DYRK2 was a potential therapeutic target,and subsequent bioinformatics analysis and cellular experiments confirmed its important role in the progression of rheumatoid arthritis and osteoporosis.(4)Furthermore,the constructed nomogram has excellent predictive performance.Finally,four potential DYRK2-targeting drugs(undecanoic acid,metyrapone,JNJ-38877605,and ACA)were discovered and molecular docking also demonstrated reliable targeting ability.(5)In conclusion,based on GWAS data from Asian and European populations,we successfully demonstrated that rheumatoid arthritis and osteoporosis are causally related at the genetic level,DYRK2 is a potential therapeutic target,and four small molecules are potential target drugs.

Objective To compare the clinical efficacy and safety differences between the triple immunosuppressive regimen of mizoribine (MZR) or mycophenolate mofetil (MMF) combined with tacrolimus (Tac) and glucocorticoids of kidney transplant recipients in one year after transplantation. Methods A single-center retrospective cohort study design was adopted. The clinical data of 156 patients who underwent the first allogeneic kidney transplantation at the Third Hospital of Peking University from January 2022 to December 2024 were included. The patients were divided into the MZR group (78 cases) and the MMF group (78 cases) based on the initial immunosuppressive regimen after transplantation. The baseline data, medication use in one year after transplantation, blood routine indicators, adverse events and clinical outcomes were compared between the two groups. For the repeated-measurement longitudinal data, repeated-measurement analysis of variance was used to evaluate the main effects of the groups, time and their interaction effects. Results At the primary efficacy endpoint, there were no statistically significant differences in the one-year survival rate, graft survival rate and incidence of acute rejection between the two groups (all P > 0.05). In terms of medication patterns and laboratory test indicators, there were significant time main effects and "time × group" interaction effects for Tac dosage (all P < 0.05). The Tac dosage in the MZR group was lower than that in the MMF group from 2 to 3 months after transplantation, and it was higher in the MZR group than in the MMF group from 7 to 12 months and one year after transplantation. White blood cell count in the MZR group was higher at one month after transplantation, and the platelet count was higher one year after transplantation (all P < 0.05). In terms of infection, the incidence of novel coronavirus and Pneumocystis jirovecii pneumonia infections in the MZR group was lower (all P < 0.05). In terms of metabolic indicators, the post-transplantation uric acid level was better in the MZR group than in the MMF group, but the total cholesterol level was higher one year after transplantation (all P < 0.05). In terms of liver function, there was a brief and mild increase in transaminase in the early stage after transplantation in the MZR group. Conclusions During the one-year follow-up after transplantation, both the MZR and MMF regimens demonstrate comparable immunosuppressive efficacy and overall safety in Chinese kidney transplant recipients. The MZR regimen shows clear advantages in reducing specific infection risks, alleviating bone marrow suppression and improving uric acid metabolism, but its potential impact on blood lipids needs to be monitored. Therefore, the MZR regimen may be an effective and safe alternative immunosuppressive option for kidney transplant recipients, especially those with high infection risk, poor hematological tolerance, or comorbid hyperuricemia.

OBJECTIVE To investigate the mechanism of Xibining Ⅱ formula in alleviating synovial inflammation and fibrosis in knee osteoarthritis （KOA） rats based on Janus kinase 2 （JAK2）/signal transducer and activator of transcription 3 （STAT3） pathway. METHODS Seventy-five male SD rats were randomly divided into sham operation group （Sham group）， KOA group， Xibining Ⅱ low-dose group （XBNⅡ-L group， 4 g/kg）， Xibining Ⅱ high-dose group （XBNⅡ-H group， 8 g/kg）， and Xibining Ⅱ high-dose combined with STAT3 activator Colivelin trifluoroacetate （C-TFA） group [C-TFA group， 8 g/kg Xibining Ⅱ+ 1.0 mg/（kg·d） C-TFA]， with 15 rats in each group. Except for the Sham group， the KOA model was established by anterior cruciate ligament transection in the other groups. After successful modeling， each group was given corresponding drugs by intragastric administration and （or） intraperitoneal injection once daily for 28 consecutive days. After the last medication， the pathological changes of synovial tissue of knee joint in each group were evaluated and the indicators were calculated. The levels of serum inflammatory factors were detected. The positive expressions of phosphorylated JAK2 （p-JAK2） and phosphorylated STAT3 （p-STAT3） in synovial tissue of the knee joint were detected. The expressions of JAK2/STAT3 pathway-related proteins and mRNAs in synovial tissue were detected. RESULTS Compared with the Sham group， the synovial lining cells in the KOA group showed significant proliferation and disordered arrangement； the Krenn score， fibrosis ratio， positive area percentage of p-JAK2 and p-STAT3， p-JAK2/JAK2 and p-STAT3/STAT3， protein expression of Collagen-Ⅰ and α -smooth muscle actin， the mRNA expression of JAK2， STAT3， Collagen-Ⅰ and α -smooth muscle actin， as well as serum levels of interleukin-1β and interleukin-18 were significantly increased （ P ＜0.05）. Compared with the KOA group， the above pathological changes were significantly improved in each dose group of Xibining Ⅱ formula， and all indicators were significantly decreased （ P ＜0.05）， with the XBNⅡ-H group showing better effects than the XBNⅡ-L group （ P ＜0.05）. Compared with the XBNⅡ-H group， the above pathological damages were aggravated in the C-TFA group， and all indicators were significantly worsened （ P ＜0.05）. CONCLUSIONS Xibining Ⅱ formula can alleviate synovial inflammation and fibrosis in KOA rats， and its mechanism may be related to inhibiting the activation of JAK2/STAT3 pathway.

Background/Aims: Metabolic dysfunction–associated steatotic liver disease (MASLD) is a chronic liver disease characterized by hepatic steatosis. Ubiquitin-specific protease 29 (USP29) plays pivotal roles in hepatic ischemiareperfusion injury and hepatocellular carcinoma, but its role in MASLD remains unexplored. Therefore, the aim of this study was to reveal the effects and underlying mechanisms of USP29 in MASLD progression. Methods: USP29 expression was assessed in liver samples from MASLD patients and mice. The role and molecular mechanism of USP29 in MASLD were assessed in high-fat diet-fed and high-fat/high-cholesterol diet-fed mice and palmitic acid and oleic acid treated hepatocytes. Results: USP29 protein levels were significantly reduced in mice and humans with MASLD. Hepatic steatosis, inflammation and fibrosis were significantly exacerbated by USP29 deletion and relieved by USP29 overexpression. Mechanistically, USP29 significantly activated the expression of genes related to fatty acid β-oxidation (FAO) under metabolic stimulation, directly interacted with long-chain acyl-CoA synthase 5 (ACSL5) and repressed ACSL5 degradation by increasing ACSL5 K48-linked deubiquitination. Moreover, the effect of USP29 on hepatocyte lipid accumulation and MASLD was dependent on ACSL5. Conclusions USP29 functions as a novel negative regulator of MASLD by stabilizing ACSL5 to promote FAO. The activation of the USP29-ACSL5 axis may represent a potential therapeutic strategy for MASLD.

Background/Aims: Metabolic dysfunction–associated steatotic liver disease (MASLD) is a chronic liver disease characterized by hepatic steatosis. Ubiquitin-specific protease 29 (USP29) plays pivotal roles in hepatic ischemiareperfusion injury and hepatocellular carcinoma, but its role in MASLD remains unexplored. Therefore, the aim of this study was to reveal the effects and underlying mechanisms of USP29 in MASLD progression. Methods: USP29 expression was assessed in liver samples from MASLD patients and mice. The role and molecular mechanism of USP29 in MASLD were assessed in high-fat diet-fed and high-fat/high-cholesterol diet-fed mice and palmitic acid and oleic acid treated hepatocytes. Results: USP29 protein levels were significantly reduced in mice and humans with MASLD. Hepatic steatosis, inflammation and fibrosis were significantly exacerbated by USP29 deletion and relieved by USP29 overexpression. Mechanistically, USP29 significantly activated the expression of genes related to fatty acid β-oxidation (FAO) under metabolic stimulation, directly interacted with long-chain acyl-CoA synthase 5 (ACSL5) and repressed ACSL5 degradation by increasing ACSL5 K48-linked deubiquitination. Moreover, the effect of USP29 on hepatocyte lipid accumulation and MASLD was dependent on ACSL5. Conclusions USP29 functions as a novel negative regulator of MASLD by stabilizing ACSL5 to promote FAO. The activation of the USP29-ACSL5 axis may represent a potential therapeutic strategy for MASLD.