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.

Abstract In recent years, the prevalence of overweight and obesity among children and adolescents has risen rapidly, posing a serious threat to their physical and mental health. To provide scientific, systematic, and standardized weight management guidance for overweight and obese children and adolescents, the study focuses on the core concept of healthy lifestyle intervention, integrates multidisciplinary expert opinions and research findings,and proposes a comprehensive multidisciplinary intervention framework covering scientific exercise intervention, precise nutrition and diet, optimized sleep management, and standardized psychological support. It calls for the establishment of a multi agent collaborative management mechanism led by the government, implemented by families, fostered by schools, initiated by individuals, optimized by communities, reinforced by healthcare, and coordinated by multiple stakeholders. Emphasizing a child and adolescent centered approach, the consensus advocates for comprehensive, multi level, and personalized guidance strategies to promote the internalization and maintenance of a healthy lifestyle. It serves as a reference and provides recommendations for the effective prevention and control of overweight and obesity, and enhancing the health level of children and adolescents.

A novel analytical method was developed in this study by combining online solid phase extraction with ultra performance liquid chromatography-tandem mass spectrometry(Online SPE-UPLC-MS/MS)for simultaneous determination of 50 kinds of steroid hormones in surface water.Specifically,after high-speed centrifugation of 4 mL water samples,the supernatant was directly injected into an Oasis HLB online SPE column for enrichment and purification.Subsequently,the target compounds were transferred to the analytical column via valve switching for separation and analysis.The chromatographic separation was performed on a Thermo Acclaim RSLC C18 column(100 mm×2.1 mm,2.2 μm),using a mobile phase composed of 5 mmol/L ammonium fluoride aqueous solution and acetonitrile.Mass spectrometric detection was conducted in positive ion mode,utilizing multiple reaction monitoring(MRM)with quantification achieved by the internal standard method.The method validation demonstrated that the limits of detection(LOD)for the 50 kinds of steroid hormones ranged from 0.02 to 0.50 ng/L,while the limits of quantification(LOQ)were between 0.08 and 1.67 ng/L.The average recoveries in surface water samples at spiked concentrations of 5,20 and 200 ng/L were between 74.1％and 119％,with relative standard deviations(RSDs)of 0.2％to 9.9％.This method was applied to analyze 11 surface water samples collected from sites surrounding a pharmaceutical and chemical industrial park.A total of 44 kinds of steroid hormones were detected,with concentrations ranging from 0.11 to 88.6 ng/L,revealing the presence of hormone contamination in the environmental waters surrounding industrial areas.Compared with the traditional offline SPE methods,the proposed online SPE technique significantly reduced sample volume requirements and pretreatment time,while minimizing the loss of target compounds during the pretreatment process.Moreover,compared to reported online SPE techniques,this method achieved high-throughput analysis of multiple classes of steroid hormones,with lower detection limits and higher recoveries.Overall,this method provided rapid sample preparation,high sensitivity,and excellent stability,making it suitable for the direct analysis of trace steroid hormones in surface water.

Pyroptosis is the programmed death of cells accompanied by an inflammatory response and is widely involved in the development of a variety of diseases, such as infectious diseases, cardiovascular diseases, and neurodegeneration. It has been shown that cellular scorching is involved in the pathogenesis of pulmonary arterial hypertension ( PAH) in cardiovascular diseases. Patients with PAH have perivascular inflammatory infiltrates in lungs, pulmonary vasculopathy exists in an extremely inflam-matory microenvironment, and pro-inflammatory factors in cellular scorching drive pulmonary vascular remodelling in PAH patients. This article reviews the role of cellular scorch in the pathogenesis of PAH and the related research on drugs for the treatment of PAH, with the aim of providing new ideas for clinical treatment of PAH.

Objective:To analyze the clinical features and risk factors of chest tightness variant asthma (CTVA) in children, so as to provide basis for the prevention and management of the disease.Methods:A cross-sectional study was conducted to analyze 178 children aged 6-17 years old who were admitted to the Department of Allergy, Capital Institute of Pediatrics Affiliated Children′s Hospital from January 2021 to January 2023 due to chest tightness. The age was 8.83(7.50, 11.58) years old, with 89 males (50%) and 89 females (50%). According to the diagnosis of CTVA, 130 cases were divided into CTVA group and 48 non-CTVA cases were divided into control group. Demographic data, personal history, family history, clinical features, auxiliary examination results and other data were collected. The clinical characteristics, allergens, FeNO level and pulmonary function parameters of the two groups were analyzed. Logistic regression analysis was used to explore the risk factors of the disease.Results:The proportion of school-age children (6-11 years old) in CTVA group was higher than that of adolescent children (≥12 years old) [(113/130,86.9%) vs (26/48,54.2%), Z=21.985, P<0.01]. The proportion of CTVA combined with eczema [(74/130,56.9%) vs (19/48,39.6%), χ2=4.225, P<0.05] and rhinitis symptoms [(98/130,75.4%) vs (27/48,56.2%), χ2=6.138, P<0.05] was higher. The positive rates of mold sensitization [(52/130,40.0%) vs (11/48,22.9%), χ2=4.474, P<0.05] and multiple sensitization [(71/130,54.6%) vs (18/48,37.5%), χ2=4.108, P<0.05] in inhaled allergens were significantly higher than those of control group. The proportion of elevated FeNO (>20 ppb) in CTVA children was 20.8% (27/130), which was significantly higher than that in control group 4.2%(2/48)( χ2=7.086 ,P<0.01). There were no statistical differences in spirometry parameters FEV 1 and FVC between CTVA group and control group ( P both>0.05). FEV 1/FVC, PEF, FEF 25, FEF 50, FEF 75 and MMEF were significantly lower than those in control group ( P all<0.05). Logistic regression analysis showed that rhinitis symptoms ( OR=2.351, 95% CI 1.105-5.002, P=0.026), multiple sensitizations ( OR=2.184, 95% CI 1.046-4.557, P=0.038), tIgE>60 kU/L( OR=3.080, 95% CI 1.239-7.654, P=0.015), FeNO>20 ppb ( OR=6.734, 95% CI 1.473-30.796, P=0.014) and small airway dysfunction ( OR=3.164, 95% CI 1.089-9.194, P=0.034) were risk factors for chest tightness variant asthma. FeNO combined with FEF 50 has the largest area under the curve ( Z=2.744, P<0.01) in diagnosing CTVA. Conclusion:CTVA is more common in school-age children than in adolescent children. Rhinitis symptoms, multiple sensitization, tIgE>60 kU/L, FeNO>20 ppb and small airway dysfunction are risk factors for chest tightness variant asthma. FeNO combined with small airway indexes can improve the diagnostic value of CTVA.

Objective To establish a rapid and sensitive liquid chromatography-tandem mass spectrometry(LC-MS/MS)analysis method for determination of unsymmetrical dimethylhydrazine(UDMH)contents in rat plasma and investigate the toxicokinetic characteristics of UDMH in rats.Methods Twenty-two SD rats were divided into the intravenous injection of 10 mg/kg dose group(4 females)and intragastric administration groups(low,medium and high dose,with 6 rats in each group,half males and half females).The rats were given 10mg/kg by intravenous administration and 10 mg/kg,30 mg/kg,and 90 mg/kg single dose of UDMH by gavage.Blood samples were collected from the orbital venous plexus at 0 hour before administration and at different time points after administration.The plasma samples were extracted with protein precipitation and derivatization before being analyzed using the LC-MS/MS method.Separation was carried out on a ZORBAX column(4.6mm×75mm,3.5 μm),with a mobile phase composed of 0.3％acetonitrile/formic acid at a flow rate of 1 mL/min.Propranolol was used as the internal standard.An electrospray ionization(Turbo Ionspray)source was applied and the mass spectrometer was operated in a positive MRM mode.Quantitative analysis showed that the ionization source unsymmetrical dimethylhydrazine and propranolol was at m/z:192.0→148.1,m/z:260.2→116.1,respectively.The toxicokinetic parameters were analyzed with the DAS 2.1 software.Results Quantification of UDMH exhibited a good linearity within the concentration range of 50-50000 ng/mL,with a linear correlation coefficient greater than 0.9900 and a lower limit of quantification of 50 ng/mL.The average recovery rate of UDMH was 98.1％,compared with 100.5％for the internal standard propranolol hydrochloride.The inter batch precision of standard curve samples ranged from 0.7％to 6.3％,and the relative error was between-7.1％and 6.2％.The inter batch and intra batch precision of quality control samples ranged from1.8％to 19.8％,and the relative error from-9.8％to 0.2％.The main pharmacokinetic parameters of UDMH in rats exposed to 10 mg/kg,30 mg/kg,and 90 mg/kg gavage were UC(0-t):(7624.99±2569.31),(34284.04±6657.15),(84720.88±22354.80)μg/L·h,t1/2:(0.07±0.15),(2.24±1.45),(3.04±0.90)h,Tmax:(0.75±0.27),(0.51±0.29),(0.29±0.10)h,Cmax:(4454.14±1329.45),(19442.45±9121.07),(32334.35±9882.41)μg/L,F:(77.34±26.06)％,(115.92±22.51)％,(95.48±25.19)％.Conclusion The LC-MS/MS method is highly accurate and specific,and is suitable for the toxicokinetic study of UDMH in rats.Single gavage administration of UDMH results in absorption and elimination saturation at a high dose.This study provides data for toxicological studies related to UDMH.

Objective:To explore the effects of the immune responses mediated by topological structures of three-dimensional bioprinted scaffolds on hair follicle cycle in mice.Methods:The study was an experimental research. The alginate-gelatin composite hydrogels were printed into scaffolds using a three-dimensional bioprinter and named T45 scaffolds, T60 scaffolds, and T90 scaffolds according to the 3 topological structures of the scaffolds (the rotation angles of the printhead during printing were 45°, 60°, and 90°, respectively), and the morphology of the three scaffolds was observed after cross-linking by naked eyes. Nine 8-week-old female C57BL/6J mice were divided into T45 group, T60 group, and T90 group, according to the random number table, with three mice in each group, and the T45, T60, and T90 scaffolds were subcutaneously implanted on the back of mice, respectively. On post implantation day (PID) 7, the hair growth in the dorsal depilated area of mice was observed, the thickness of the fiber capsule around the scaffolds was observed by hematoxylin-eosin staining, and the expression levels of CD68, bone morphogenetic protein-2 (BMP-2), and tumor necrosis factor (TNF) protein in the tissue surrounding the scaffolds were observed by immunofluorescence staining. The samples of the above experiments were all 3.Results:The topological structures of the three scaffolds were all clear with high fidelity after cross-linking. On PID 7, the hair growth was obvious in the dorsal depilated area of mice in T45 group and T90 group, while hair growth was slow in the scaffold implantation area of mice in T60 group, which was significantly different from that of the unimplanted area. On PID 7, compared with (18±4) μm in T90 group, the thickness of both the fiber capsule around the scaffolds ((39±4) and (55±8) μm) of mice in T45 group and T60 group was significantly increased ( P<0.05); the thickness of the fiber capsule around the scaffolds of mice in T60 group was also significantly increased compared with that in T45 group ( P<0.05). On PID 7, the expression level of CD68 protein in the tissue surrounding the scaffolds of mice in T60 group was significantly higher than the levels in T45 group and T90 group (with both P values <0.05). The expression level of BMP-2 protein in the tissue surrounding the scaffolds of mice in T60 group was significantly higher than the levels in T45 group and T90 group (with both P values <0.05), and the expression level of BMP-2 protein in the tissue surrounding the scaffolds of mice in T45 group was significantly higher than that in T90 group ( P<0.05). The expression level of TNF protein in the tissue surrounding the scaffolds of mice in T60 group was significantly lower than the levels in T45 group and T90 group (with both P values <0.05). Conclusions:Three-dimensional bioprinted scaffolds with different topological structures mediate different degrees of immune responses after being implanted in mice. A moderate immune response promotes hair growth in depilated area of mice, while an excessive immune response results inhibits the hair follicle entering into the anagen phase.

Objective:To analyze the clinical features and risk factors of chest tightness variant asthma (CTVA) in children, so as to provide basis for the prevention and management of the disease.Methods:A cross-sectional study was conducted to analyze 178 children aged 6-17 years old who were admitted to the Department of Allergy, Capital Institute of Pediatrics Affiliated Children′s Hospital from January 2021 to January 2023 due to chest tightness. The age was 8.83(7.50, 11.58) years old, with 89 males (50%) and 89 females (50%). According to the diagnosis of CTVA, 130 cases were divided into CTVA group and 48 non-CTVA cases were divided into control group. Demographic data, personal history, family history, clinical features, auxiliary examination results and other data were collected. The clinical characteristics, allergens, FeNO level and pulmonary function parameters of the two groups were analyzed. Logistic regression analysis was used to explore the risk factors of the disease.Results:The proportion of school-age children (6-11 years old) in CTVA group was higher than that of adolescent children (≥12 years old) [(113/130,86.9%) vs (26/48,54.2%), Z=21.985, P<0.01]. The proportion of CTVA combined with eczema [(74/130,56.9%) vs (19/48,39.6%), χ2=4.225, P<0.05] and rhinitis symptoms [(98/130,75.4%) vs (27/48,56.2%), χ2=6.138, P<0.05] was higher. The positive rates of mold sensitization [(52/130,40.0%) vs (11/48,22.9%), χ2=4.474, P<0.05] and multiple sensitization [(71/130,54.6%) vs (18/48,37.5%), χ2=4.108, P<0.05] in inhaled allergens were significantly higher than those of control group. The proportion of elevated FeNO (>20 ppb) in CTVA children was 20.8% (27/130), which was significantly higher than that in control group 4.2%(2/48)( χ2=7.086 ,P<0.01). There were no statistical differences in spirometry parameters FEV 1 and FVC between CTVA group and control group ( P both>0.05). FEV 1/FVC, PEF, FEF 25, FEF 50, FEF 75 and MMEF were significantly lower than those in control group ( P all<0.05). Logistic regression analysis showed that rhinitis symptoms ( OR=2.351, 95% CI 1.105-5.002, P=0.026), multiple sensitizations ( OR=2.184, 95% CI 1.046-4.557, P=0.038), tIgE>60 kU/L( OR=3.080, 95% CI 1.239-7.654, P=0.015), FeNO>20 ppb ( OR=6.734, 95% CI 1.473-30.796, P=0.014) and small airway dysfunction ( OR=3.164, 95% CI 1.089-9.194, P=0.034) were risk factors for chest tightness variant asthma. FeNO combined with FEF 50 has the largest area under the curve ( Z=2.744, P<0.01) in diagnosing CTVA. Conclusion:CTVA is more common in school-age children than in adolescent children. Rhinitis symptoms, multiple sensitization, tIgE>60 kU/L, FeNO>20 ppb and small airway dysfunction are risk factors for chest tightness variant asthma. FeNO combined with small airway indexes can improve the diagnostic value of CTVA.