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.

Cellulose synthase (CesA), one of the key enzymes in the biosynthesis of cellulose in plants, plays an important role in plant growth and plant resistance. In this study, a total of 21 AsCesA genes from Aquilaria sinensis were systematically identified and the physico-chemical characteristics were analyzed based on genome database and bioinformatical methods. The phylogenetic tree was constructed and the gene location on chromosome, cis-acting elements in the 2 000 basepairs upstream regulatory regions and conservative motifs were analyzed. The AsCesA proteins were mainly located on the plasma membrane. The number of amino acids of the proteins ranged from 390 to 1 261. The isoelectric point distributed from 5.67 to 8.86. All of the 21 AsCesA proteins possessed the transmembrane domains, the number of which was from 6 to 8. The genes were classified into 3 groups according to the phylogenetic relationship. Obvious differences were observed in motif composition in genes from different groups. However, motif2, motif6, motif7 and motif10 were observed in all of AsCesA proteins. Analysis of cis-acting elements indicated that AsCesA genes family has cis-acting elements related to plant hormones, abiotic stresses, and biological processes. Seven AsCesA genes with differential expression were selected according to the calli transcriptome data induced by NaCl at different times and their expression levels under different abiotic stresses were analyzed by quantitative real-time PCR. The results indicated that salt, low temperature, drought, and heavy metal stresses could affect the expression level of AsCesA genes, and the abundance of AsCesA1, AsCesA3 and AsCesA20 showed a significant change, implying their potential important roles to the abiotic stresses. The accumulation pattern of cellulose content under different abiotic stresses was similar to the expression trend of AsCesA genes. Our results provide valuable insights into the role of cellulose synthase in A.sinensis in plant defense.

Brasilicardin A, a diterpene glycoside isolated from pathogenic actinomycete Nocardia brasiliensis IFM 0406, has become a novel immunosuppressant candidate due to its significant immunosuppressive activity, low toxicity and unique mechanism of action. However, brasilicardin A and its analogues have become a research hotspot to the development of this promising immunosuppressant because of the low-yield production in the natural pathogenic producer and the synthetically challenging skeleton. According to the reported biosynthetic pathway of brasilicardin A, the function of involved diterpene synthase was analyzed by bioinformatics. Then the genes bra1-5 that synthesize the brasilicardin A skeleton were directionally amplified from the pathogenic strain N. brasiliensis IFM 0406, and heterologous expression was achieved successfully in Streptomyces albus R1. The compounds were isolated and purified by using various column chromatographies including silica gel column chromatography and semi-preparative HPLC. Six new brasilicardins were established and named brasilicardin H-M. The activity of brasilicardins was screened using lipopolysaccharide (LPS)-activated mouse primary macrophage inflammation model. Brasilicardin H-M exhibited good inhibitory activity on nitric oxide (NO) release with IC₅₀ values of 28.24 ± 3.70, 37.44 ± 2.00, 39.85 ± 4.02, 26.77 ± 4.40, 65.25 ± 1.48 and 15.24 ± 2.72 μmol·L^-1, respectively (indomethacin as the positive control with IC₅₀ value of 34.28 ± 4.10 μmol·L^-1). The results indicated that six compounds had potential anti-inflammatory activity. This study laid a foundation for the elucidation of the brasilicardin A biosynthetic pathway and evaluation of the structure-activity relationship as well as new drug developments.

Sucrose synthase plays a crucial role in the plant sugar metabolism pathway by catalyzing the production of uridine diphosphate (UDP)-glucose, which serves as a bioactive glycosyl donor for various metabolic processes. In this study, a sucrose synthase gene named CtSus was cloned from Cistanche tubulosa, a traditional Chinese medicine known for its rich content of diverse glycosides, based on transcriptome analysis results. The open reading frame of CtSus was 2 418 bp long encoding 805 amino acids. Sequence analysis revealed conserved domains associated with the plant sucrose synthase family at both the N-terminal and C-terminal regions of CtSus protein. Phylogenetic analysis demonstrated that CtSus shares a close evolutionary relationship with sucrose synthases from other plants within the same order. Functional identification of CtSus was performed through whole-cell catalysis coupling with UGT71BD1, a characterized glycosyltransferase enzyme. The results showed that the introduction of CtSus significantly enhanced the conversion rate of glycosylation catalyzed by UGT71BD1. The soluble expression of CtSus in Escherichia coli was further achieved using the pCold^TM TF expression vector. In vitro enzymatic assay indicated the activity of CtSus to catalyze the formation of UDP-glucose in the presence of sucrose and UDP. Real-time quantitative-polymerase chain reaction results showed that the expression patterns of CtSus gene in different parts of C. tubulosa and the suspension cell cultures of C. tubulosa under drought stress correlated with the accumulation patterns observed for phenylethanol glycosides, respectively. Furthermore, key amino acids and their interactions between enzyme and substrate were explored based on protein structure prediction and molecular docking results. Overall, our findings identify a sucrose synthase CtSus responsible for the supply of the active glycosyl donor UDP-glucose during the biosynthesis of glycoside products in C. tubulosa and have also provided a gene element that can be utilized in engineering strain construction for glycoside products production.

Objective: To explore the characteristics of plasma Epstein-Barr virus (EBV) DNA in primary infection in pediatric cases. Methods: The laboratory and clinical data of 571 children diagnosed with EBV primary infection in Children's Hospital of Fudan University during September 1^st, 2017 to September 30^th, 2018 were retrospectively analyzed. According to the results of plasma EBV DNA, they were divided into positive group and negative group. According to the EBV DNA, they were devided into high plasma virol load group and low plasma virol load group. The Chi-square test, Wilcoxon rank sum test were used to compare the differences between groups. Results: Among the 571 children with EBV primary infection, 334 were males and 237 were females. The age of first diagnosis was 3.8 (2.2, 5.7) years. There were 255 cases in positive group and 316 cases in negative group. The percentage of cases with fever,hepatomegaly and (or) splenomegaly, elevated transaminase in the positive group were higher than those in the negative group (235 cases (92.2%) vs. 255 cases (80.7%), χ²=15.22, P<0.001; 169 cases (66.3%) vs. 85 cases (26.9%), χ²=96.80, P<0.001; and 144 cases (56.5%) vs. 120 cases (38.0%), χ²=18.27, P<0.001; respectively).In the positive group, 70 cases were followed up for 46 (27, 106) days, 68 cases (97.1%) turned negative within 28 days, with the exception of 2 cases (2.9%) developed chronic active EBV infection by follow-up revision.There were 218 cases in high plasma viral DNA copies group and 37 cases in low copies group. More cases presented with elevated transaminases in the high plasma viral DNA copies group than those in the low group (75.7% (28/37) vs. 56.0%(116/207), χ²=5.00, P=0.025).Both the positive rate of EBV DNA in peripheral blood leukocytes (84.2% (266/316) vs. 44.7% (255/571), χ²=76.26, P<0.001) and the copies of EBV DNA (7.0×10⁷ (1.3×10⁷, 3.0×10⁸) vs. 3.1×10⁶ (1.6×10⁶, 6.1×10⁶) copies /L, Z=15.23, P<0.001) were higher than that of plasma. Conclusions: In immunocompetent pediatric cases diagnosed as EBV primary infection, cases with positive plasma EBV DNA were prone to have fever, hepatomegaly and (or) splenomegaly, and elevated transaminase than those with negative plasma viral DNA. The plasma EBV DNA usually turns negative within 28 days after initial diagnosis.Most cases with high viral load in plasma showed elevated aminotransferase.
Female ; Male ; Humans ; Child ; DNA, Viral ; Herpesvirus 4, Human ; Epstein-Barr Virus Infections ; Hepatomegaly ; Retrospective Studies ; Splenomegaly ; Fever ; Transaminases

As a biocatalyst, enzyme has the advantages of high catalytic efficiency, strong reaction selectivity, specific target products, mild reaction conditions, and environmental friendliness, and serves as an important tool for the synthesis of complex organic molecules. With the continuous development of gene sequencing technology, molecular biology, genetic manipulation, and other technologies, the diversity of enzymes increases steadily and the reactions that can be catalyzed are also gradually diversified. In the process of enzyme-catalyzed synthesis, the majority of common enzymatic reactions can be achieved by single enzyme catalysis, while many complex reactions often require the participation of two or more enzymes. Therefore, the combination of multiple enzymes together to construct the multi-enzyme cascade reactions has become a research hotspot in the field of biochemistry. Nowadays, the biosynthetic pathways of more natural products with complex structures have been clarified, and secondary metabolic enzymes with novel catalytic activities have been identified, discovered, and combined in enzymatic synthesis of natural/unnatural molecules with diverse structures. This study summarized a series of examples of multi-enzyme-catalyzed cascades and highlighted the application of cascade catalysis methods in the synthesis of carbohydrates, nucleosides, flavonoids, terpenes, alkaloids, and chiral molecules. Furthermore, the existing problems and solutions of multi-enzyme-catalyzed cascade method were discussed, and the future development direction was prospected.
Biological Products/chemistry* ; Catalysis ; Alkaloids ; Biocatalysis

Objective:To explore the incidence, clinical characteristics, imaging features, clinical outcome and prognosis of indeterminate pulmonary nodules (IPN) in patients with osteosarcoma.Methods:A total of 69 patients of osteosarcoma with IPN in lung treated in the Bone tumor Center of Eastern Theater General Hospital from January 2011 to January 2021 were collected retrospectively, there were 47 males and 22 females, with a median age of 19 years old (range 7-60 years old). The clinical characteristics including disease-free interval, the chemotherapy response, with recurrence/non-pulmonary, IPN presence before / during / after chemotherapy and imaging features of IPN including number of IPN, location of IPN, density of IPN, boundary clarity of IPN and outcome. The patients were divided into the metastasis pulmonary nodules group and the benign nodules group according to the final outcome of IPN. Further, χ 2 test was performed for comparison of the clinical and imaging characteristics between the two groups. The survival of patients was counted and the correlation between single factor and survival was compared by Kaplan-Meier test, and multivariate survival analyses were performed using Cox proportional hazards regression models. Results:Sixty-nine cases occurred IPN in 211 patients with osteosarcoma, with an incidence of 32.7%. Of the 69 patients, 45 patients (65.2%) with IPN were diagnosed as metastases, and 24 patients (34.8%) with IPN were diagnosed as benign nodules. Follow-up length ranged from 1 to 124 months, with the median follow up time 43 months. To the end of follow-up, 41 patients (59.4%) remained alive and 28 patients (40.6%) had died. The median survival time was 41.0 (20.0, 65.0) months and the median survival time after diagnosis of IPN was 25.0 (10.0, 43.0) months. There were significant differences in lung nodule density ( P<0.001), boundary ( P=0.002), history of recurrence/extra-pulmonary metastasis ( P=0.023) and chemotherapeutic effect ( P<0.001) between the metastasis pulmonary nodules group and the benign nodules group. Multivariate survival analysis showed that chemotherapeutic effect was an independent factor affecting the overall survival of patients [ HR=0.048, 95% CI (0.01, 0.26)]. Boundary definition [ HR=0.12, 95% CI (0.02, 0.93)] and chemotherapeutic effect [ HR=0.06, 95% CI (0.01, 0.29)] were independent factors influencing survival after diagnosis of IPN. Conclusion:Osteosarcoma patients with IPN have a poor prognosis. The poor effect of chemotherapy is an independent risk factor for the overall survival time of those patients and the survival time after diagnosis of IPN. The boundary definition of IPN is an independent risk factor for the survival time after diagnosis of IPN.

Gastrointestinal tumors(GT)are characterized by both high malignancy and high mortality and have become the major diseases for prevention in the elderly.GT often present detectable changes, including bleeding and abnormal mucosal morphology.However, many technical difficulties remain in accurately monitoring the tumor itself and related abnormal lesions mentioned above, which are the key factors affecting the early detection rate of gastrointestinal tumors.In recent years, with progresses in artificial intelligence(AI)applications for digestive endoscopy image analysis, biosensors, new biomarkers and other areas, AI holds promise for the detection of bleeding, morphological and structural abnormalities of the mucosa, tumors and other major disorders.Here we review the progress of AI applications in geriatric digestive diseases affecting digestive organs and the mucosa in light of morphology and function, to provide a reference for reducing the incidence of both geriatric emergencies and GT.