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.

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 and aims:Studies indicate that the gut microbiota and its metabolites are involved in the progression of cardiovascular diseases,and enterohepatic circulation plays an important role in this progression.This study aims to identify potential probiotics for the treatment of unstable angina(UA)and elucidate their mechanisms of action.Methods:Initially,the gut microbiota from patients with UA and control was analyzed.To directly assess the effects of Bifidobacterium supplementation,10 patients with UA were enrolled and administered Bifidobacterium(630 mg per intake twice a day for 1 month).The fecal metagenome,serum trimethyl-amine N-oxide(TMAO)levels,and other laboratory parameters were evaluated before and after Bifido-bacterium supplementation.Results:After supplementing with Bifidobacterium for 1 month,there were statistically significant dif-ferences(P＜0.05)in TMAO,aspartate aminotransferase,total cholesterol,and low-density lipoprotein compared to before.Additionally,the abundance of Bifidobacterium longum increased significantly,although the overall abundance of Bifidobacterium did not reach statistical significance.The gut micro-biota,metabolites,and gut-liver axis are involved in the progression of UA,and potential mechanisms should be further studied.Conclusions:Metagenomic analysis demonstrated a reduced abundance of Bifidobacterium in patients with UA.Supplementation with Bifidobacterium restored gut dysbiosis and decreased circulating TMAO levels in patients with UA.This study provides evidence that Bifidobacterium may exert cardiovascular-protective effects through the gut-liver-heart axis.

Objective:To explore the prognostic factors predicting the recovery of elderly patients with hospital-acquired pneumonia(HAP).Methods:Data of HAP inpatients aged over 60 years in the First Affiliated Hospital of Nanjing Medical University between October 2015 and October 2020 were collected.Body mass index(BMI), neutrophil/lymphocyte rate(NLR), Charlson Comorbidity Index(CCI), Combined Comorbidity Score(CCS)and other data were retrospectively analyzed.The predictive value of the related factors was evaluated by using the Student's t test, the Logistic regression model and the receiver operating characteristic curve(ROC). Results:A total of 200 cases were enrolled in this study, and grouped into survival group(n=158)and death group(n=42). There were significant differences between the death group and the survival group in length of age, BMI hospital stay, state of consciousness, swallowing function, indwelling gastric tube, the use of proton pump inhibitors, leukocyte count, lymphocyte count, neutrophil count, hemoglobin, NLR, albumin, alanine aminotransferase, aspartate aminotransferase, D-dimer, C-reaction protein, procalcitonin(all P<0.05). Scores of CCI and CCS were higher in the death group than in the survival group[(6.79±2.86) vs.(3.42±1.98), (6.21±3.08) vs.(1.66±1.94), t=-7.193, -9.116, both P<0.001]. Multivariate Logistic analysis showed that age>86 years( OR=1.155, 95% CI: 1.014-1.316), BMI<21.77 kg/m 2( OR=0.651, 95% CI: 0.480-0.883), neutrophil count>10.10×10 9/L( OR=1.208, 95% CI: 1.025-1.422), C-reaction protein>59.32 mg/L( OR=1.055, 95% CI: 1.018-1.093), CCS>6.21 scores( OR=2.859, 95% CI: 1.559-5.244)were risk factors for death inpatients aged 60 years and older with HAP.Area under the ROC curve showed that CCS could better predict the mortality of elderly patients than CCI, and the areas under the ROC curve were 0.831(95% CI: 0.753-0.909)and 0.898(95% CI: 0.850-0.946)respectively(both P< 0.001). Conclusions:The elderly patients with HAP are inclined to multiplecomplications and high mortality rates.Combined application of multiple assessment systems and clinical indicators can improve the ability to predict the outcome of HAP.