OBJECTIVES: Sepsis-associated acute lung injury (S-ALI) is one of the major causes of death in intensive care unit (ICU) patients, yet its mechanisms remain incompletely understood and effective therapies are lacking. Lytic cell death of macrophages is a key driver of the inflammatory cascade in S-ALI. PANoptosis, a newly recognized form of lytic cell death characterized by PANoptosome assembly and activation, involves plasma membrane rupture (PMR) mediated by ninjurin-1 (NINJ1), a recently identified pore-forming protein. Itaconic acid is known for its anti-inflammatory effects, but its role in macrophage PANoptosis during S-ALI is unclear. This study aims to investigate the protective effect of itaconic acid on macrophage PANoptosis in S-ALI to provide new therapeutic insights. METHODS: Male specific-pathogen-free C57BL/6J mice (6-8 weeks, 18-20 g) received intraperitoneal lipopolysaccharide (LPS) to establish a classical S-ALI model. Western blotting was used to assess PANoptosome-related proteins and enzymes involved in the itaconic acid metabolic pathway, while real-time reverse transcription polymerase chain reaction and metabolomics quantified itaconic acid levels. Primary peritoneal macrophages (PMs) were pretreated with the itaconate derivative 4-octyl itaconate (4-OI) and then exposed to tumor necrosis factor alpha (TNF-α) plus interferon gamma (IFN-γ) to induce PANoptosis. Cell viability was evaluated by cell counting kit-8 (CCK-8) assay. Western blotting was employed to quantify enzymes of the itaconate-metabolic pathway in PANoptotic macrophages, to evaluate the impact of 4-OI on PANoptosome-associated proteins, and to determine NINJ1 abundance in lung tissues from S-ALI mice and in PANoptotic macrophages. Fluorescent dye FM_4-64 was used to visualize 4-OI-mediated changes in PMR, whereas immunofluorescence staining mapped the effect of 4-OI on both the expression level and membrane localization of NINJ1 in PANoptotic macrophages. The effect of 4-OI on lactate dehydrogenase (LDH) release in culture supernatants and peripheal blood serum was assessed using a LDH assay kit, and non-denataring polyacylamide gel electrophoresis was used to assess the expression of NINJ1 in S-ALI mouse lung tissues and the impact of 4-OI on the expression of PANoptosis-associated NINJ1 multimeric reflected protein in macropahges. RESULTS: In S-ALI mouse lungs, PANoptosome components [NOD-like receptor thermal protein domain associated protein 3 (NLRP3), Gasdermin D (GSDMD), Caspase-1, Z-DNA binding protein (ZBP1), and Caspase-3] and phosphorylated mixed lineage kinase domain-like protein (MLKL) S345 were significantly upregulated (all P<0.05), while metabolomics showed compensatory increases in itaconic acid and its key enzymes [aconitate decarboxylase 1 (ACOD1)/immunoresponsive gene 1 (IRG1)]. In macrophages, 4-OI obviously suppressed PANoptosome protein expression, reduced LDH release, restored plasma membrane integrity, and inhibited NINJ1 expression and oligomerization at the membrane (P<0.05). CONCLUSIONS Itaconic acid may alleviate macrophage PANoptosis in S-ALI by inhibiting NINJ1-mediated plasma membrane rupture. Targeting NINJ1 or enhancing itaconate pathways may offer a novel therapeutic strategy for S-ALI.
Animals ; Acute Lung Injury/pathology* ; Succinates/pharmacology* ; Sepsis/complications* ; Mice, Inbred C57BL ; Male ; Mice ; Macrophages/pathology* ; Cell Membrane/metabolism* ; Lipopolysaccharides ; Hydro-Lyases

This study aimed to analyze the impact of single nucleotide polymorphism (SNP) of ADCY3 (encoding adenylate cyclase 3) on the outcome of high-intensity interval training (HIIT) on body composition and screen genetic markers sensitive to HIIT in Chinese Han youth. A total of 237 non-regular exercise Han college students were recruited in a 12-week HIIT program, attending sessions 3 times a week. Before and after the HIIT program, their body composition was measured. DNA from the white blood cells was extracted and genotyped. PLINK (V1.09) software was used for quality control screening of SNPs loci, and a linear regression model was constructed to analyze the association between ADCY3 gene SNPs loci and body composition. ANOVA multiple comparisons (LSD) were performed to test the difference between groups, with the significance level set at 0.05. The results showed that: 1) A total of 22 SNPs loci were identified by the gene microarray scanning of ADCY3 gene, with 15 of them meeting the quality control criteria. The rs6753096 locus was associated with the training effect of HIIT on body composition; 2) The rs6753096 locus was not associated with pre-HIIT body composition; 3) Compared with volunteers with TT genotype, those with CT/CC genotype exhibited significant decrease in body mass index (BMI) and total body fat after training (P < 0.05); Male volunteers carrying the C allele had more significant training changes in skeletal muscle and lean body weight, while HIIT was more effective in decreasing body fat in female volunteers with CT/CC genotype; 4) The rs6753096 locus was significantly correlated with body fat sensitivity to HIIT (P = 0.0475), indicating that volunteers with CT/CC genotype were more sensitive to HIIT. In conclusion, 12-week HIIT program effectively improved the body composition of college students. The ADCY3 gene rs6753096 locus is not associated with pre-HIIT body composition, but it is associated with body composition sensitivity to HIIT, with individuals carrying CT/CC genotype showing greater responsiveness to HIIT.
Humans ; Adenylyl Cyclases/genetics* ; Male ; Female ; Body Composition/genetics* ; Polymorphism, Single Nucleotide ; Young Adult ; High-Intensity Interval Training/methods* ; Genotype ; Adult ; Adolescent

Itaconate is a pivotal intermediate metabolite in the tricarboxylic acid (TCA) cycle of immune cells. It is produced by decarboxylation of cis-aconitic acid under the catalysis of aconitate decarboxylase 1 (ACOD1), which is encoded by the immune response gene 1 (IRG1). Itaconate has become a focal point of research on immunometabolism. Studies have demonstrated that itaconate plays a crucial role in diseases by regulating inflammation, remodeling cell metabolism, and participating in epigenetic regulation. This paper reviewed the research progress in itaconnate from its chemical structure, regulatory effects on different diseases, and mechanisms, proposes the future research directions, aiming to provide a theoretical basis for the development of itaconate-related drugs.
Humans ; Succinates/metabolism* ; Carboxy-Lyases/genetics* ; Inflammation/metabolism* ; Citric Acid Cycle ; Animals ; Epigenesis, Genetic ; Neoplasms/immunology*

OBJECTIVE: To explore the driving gene of hepatocellular carcinoma (HCC) occurrence and progression and its potential as new therapeutic target of HCC. METHODS: The transcriptome and genomic data of 858 HCC tissues and 493 adjacent tissues were obtained from TCGA, GEO, and ICGC databases. Gene Set Enrichment Analysis (GSEA) identified EHHADH (encoding enoyl-CoA hydratase/L-3-hydroxyacyl-CoA dehydrogenase) as the hub gene in the significantly enriched differential pathways in HCC. The downregulation of EHHADH expression at the transcriptome level was found to correlate with TP53 mutation based on analysis of the TCGA- HCC dataset, and the mechanism by which TP53 mutation caused EHHADH downregulation was explored through correlation analysis. Analysis of the data from the Metascape database suggested that EHHADH was strongly correlated with the ferroptosis signaling pathway in HCC progression, and to verify this result, immunohistochemical staining was used to examine EHHADH expression in 30 HCC tissues and paired adjacent tissues. RESULTS: All the 3 HCC datasets showed signficnatly lowered EHHADH expression in HCC tissues as compared with the adjacent tissues (P < 0.05) with a close correlation with the degree of hepatocyte de-differentiation (P < 0.01). The somatic landscape of HCC cohort in TCGA dataset showed that HCC patients had the highest genomic TP53 mutation rate. The transcriptomic level of PPARGC1A, the upstream gene of EHHADH, was significantly downregulated in HCC patients with TP53 mutation as compared with those without the mutation (P < 0.05), and was significantly correlated with EHHADH expression level. GO and KEGG enrichment analyses showed that EHHADH expression was significantly correlated with abnormal fatty acid metabolism in HCC. The immunohistochemical results showd that the expression level of EHHADH in HCC tissues was down-regulated, and its expression level was related to the degree of hepatocytes de-differentiation and the process of ferroptosis. CONCLUSION TP53 mutations may induce abnormal expression of PPARGC1A to cause downregulation of EHHADH expression in HCC. The low expression of EHHADH is closely associated with aggravation of de-differentiation and ferroptosis escape in HCC tissues, suggesting the potential of EHHADH as a therapeutic target for HCC.
Humans ; Carcinoma, Hepatocellular/genetics* ; Transcriptome ; Liver Neoplasms/genetics* ; Gene Expression Profiling ; Fatty Acids ; Peroxisomal Bifunctional Enzyme

Aims: Heterologous holoenzyme formation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) has been a challenge due to a limited understanding of its biogenesis. Unlike bacterial Rubiscos, eukaryotic Rubiscos are incompatible with the Escherichia coli (E. coli) chaperone system to fold and assemble into the functional hexadecameric conformation (L8S8), which comprises eight large subunits (RbcL) and eight small subunits (RbcS). Our previous study reported three sections (residues 248-297, 348-397 and 398-447) within the RbcL of Synechococcus elongatus PCC6301, which may be important for the formation of L8S8 in E. coli. The present study further examined these three sections separately, dividing them into six sections of 25 residues (i.e., residues 248-272, 273-297, 348-372, 373-397, 398-422 and 423-447). Methodology and results: Six chimeric Rubiscos with each section within the RbcL from Synechococcus replaced by their respective counterpart sequence from Chlamydomonas reinhardtii were constructed and checked for their effect on holoenzyme formation in E. coli. The present study shows that Section 1 (residues 248-272; section of Synechococcus RbcL replaced by corresponding Chlamydomonas sequence), Section 2 (residues 273-297), Section 3 (residues 348-372) and Section 6 (residues 423-447) chimeras failed to fold and assemble despite successful expression of both RbcL and RbcS. Only Section 4 (residues 373-397) and 5 (residues 398-422) chimeras could form L8S8 in E. coli. Conclusion, significance and impact of study GroEL chaperonin mediates the folding of bacterial RbcL in E. coli. Therefore, residues 248-297, 348-372 and 423-447 of Synechococcus RbcL may be important for interacting with the GroEL chaperonin for successful holoenzyme formation in E. coli.
Synechococcus ; Ribulose-Bisphosphate Carboxylase ; Escherichia coli ; Holoenzymes

In order to explore the functions of genes of key rate-limiting enzymes chalcone isomerase(CHI) and chalcone synthase(CHS) in the biosynthesis of flavonoids in Lonicera macranthoides, this study screened and cloned the cDNA sequences of CHI and CHS genes from the transcriptome data of conventional variety and 'Xianglei' of L. macranthoides. Online bioinformatics analysis software was used to analyze the characteristics of the encoded proteins, and quantitative reverse-transcription polymerase chain reaction(qRT-PCR) to detect the expression of CHI and CHS in different parts of the varieties at different flowering stages. The content of luteo-loside was determined by high performance liquid chromatography(HPLC) and the correlation with the expression of the two genes was analyzed. The results showed that the CHI and CHS of the two varieties contained a 627 bp and 1170 bp open reading frame(ORF), respectively, and the CHI protein and CHS protein were stable, hydrophilic, and non-secretory. qRT-PCR results demonstrated that CHI and CHS of the two varieties were differentially expressed in stems and leaves at different flowering stages, particularly the key stages. Based on HPLC data, luteoloside content was in negative correlation with the relative expression of the genes. Thus, CHI and CHS might regulate the accumulation of flavonoids in L. macranthoides, and the specific functions should be further studied. This study cloned CHI and CHS in L. macranthoides and analyzed their expression for the first time, which laid a basis for investigating the molecular mechanism of the differences in flavonoids such as luteoloside in L. macranthoides and variety breeding.
Acyltransferases/metabolism* ; Chalcone ; Cloning, Molecular ; Intramolecular Lyases ; Lonicera/metabolism* ; Plant Breeding

1, 5-diaminopentane, also known as cadaverine, is an important raw material for the production of biopolyamide. It can be polymerized with dicarboxylic acid to produce biopolyamide PA5X whose performances are comparable to that of the petroleum-based polyamide materials. Notably, biopolyamide uses renewable resources such as starch, cellulose and vegetable oil as substrate. The production process does not cause pollution to the environment, which is in line with the green and sustainable development strategy. The biosynthesis of 1, 5-diaminopentane mainly includes two methods: the de novo microbial synthesis and the whole cell catalysis. Lysine decarboxylase as the key enzyme for 1, 5-diaminopentane production, mainly includes an inducible lysine decarboxylase CadA and a constituent lysine decarboxylase LdcC. Lysine decarboxylase is a folded type Ⅰ pyridoxal-5' phosphate (PLP) dependent enzyme, which displays low activity and unstable structure, and is susceptible to deactivation by environmental factors in practical applications. Therefore, improving the catalytic activity and stability of lysine decarboxylase has become a research focus in this field, and molecular engineering and immobilization are the mainly approaches. Here, the mechanism, molecular engineering and immobilization strategies of lysine decarboxylase were reviewed, and the further strategies for improving its activity and stability were also prospected, with the aim to achieve efficient production of 1, 5-diaminopentane.
Escherichia coli/metabolism* ; Carboxy-Lyases/metabolism* ; Catalysis ; Cadaverine/metabolism*

p-coumaric acid is one of the aromatic compounds that are widely used in food, cosmetics and medicine due to its properties of antibacterium, antioxidation and cardiovascular disease prevention. Tyrosine ammonia-lyase (TAL) catalyzes the deamination of tyrosine to p-coumaric acid. However, the lack of highly active and specific tyrosine ammonia lyase limits cost-effective microbial production of p-coumaric acid. In order to improve biosynthesis efficiency of p-coumaric acid, two tyrosine ammonia-lyases, namely Fc-TAL2 derived from Flavobacterium columnare and Fs-TAL derived from Flavobacterium suncheonense, were selected and characterized. The optimum temperature (55 ℃) and pH (9.5) for Fs-TAL and Fc-TAL2 are the same. Under optimal conditions, the specific enzyme activity of Fs-TAL and Fc-TAL2 were 82.47 U/mg and 13.27 U/mg, respectively. Structural simulation and alignment analysis showed that the orientation of the phenolic hydroxyl group of the conserved Y50 residue on the inner lid loop and its distance to the substrate were the main reasons accounting for the higher activity of Fs-TAL than that of Fc-TAL2. The higher activity and specificity of Fs-TAL were further confirmed via whole-cell catalysis using recombinant Escherichia coli, which could convert 10 g/L tyrosine into 6.2 g/L p-coumaric acid with a yield of 67.9%. This study provides alternative tyrosine ammonia-lyases and may facilitate the microbial production of p-coumaric acid and its derivatives.
Ammonia-Lyases/chemistry* ; Coumaric Acids ; Escherichia coli/genetics* ; Tyrosine

Ornithine decarboxylase (ODC) is a key enzyme in the biosynthetic pathway of polyamines and catalyzes the decarboxylation of ornithine to produce putrescine. Inhibition of ODC activity is a potential approach for the prevention and treatment of many diseases including cancer, as the expression levels and the activities of ODC in many abnormal cells and tumor cells are generally higher than those of normal cells. The discovery and evaluation of ODC inhibitors rely on the monitoring of the reaction processes catalyzed by ODC. There are several commonly used methods for analyzing the activity of ODC, such as measuring the yield of putrescine by high performance liquid chromatography, or quantifying the yield of isotope labelled carbon dioxide. However, the cumbersome operation and cost of these assays, as well as the difficulty to achieve high-throughput and real-time detection, hampered their applications. In this work, we optimized a real-time label-free method for analyzing the activity of ODC based on the macromolecule cucurbit[6]uril (CB6) and a fluorescent dye, DSMI (trans-4-[4-(dimethylamino) styryl]-1-methylpyridinium iodide). Finally, the optimized method was used to determine the activities of different ODC inhibitors with different inhibition mechanisms.
Bridged-Ring Compounds ; Imidazoles ; Ornithine ; Ornithine Decarboxylase ; Ornithine Decarboxylase Inhibitors ; Putrescine

Terpenoid indole (TIAs) and β-carboline alkaloids (BCAs), such as suppressant reserpine, vasodilatory yohimbine, and antimalarial quinine, are natural compounds derived from strictosidine. These compounds can exert powerful pharmacological effects but be obtained from limited source in nature. the whole biosynthetic pathway of TIAs and BCAs, The Pictet-Spengler reaction catalyzed by strictosidine synthase (STR; EC: 4.3.3.2) is the rate-limiting step. Therefore, it is necessary to investigate their biosynthesis pathways, especially the role of STR, and related findings will support the biosynthetic generation of natural and unnatural compounds. This review summarizes the latest studies concerning the function of STR in TIA and BCA biosynthesis, and illustrates the compounds derived from strictosidine. The substrate specificity of STR based on its structure is also summarized. Proteins that contain six-bladed four-stranded β-propeller folds in many organisms, other than plants, are listed. The presence of these folds may lead to similar functions among organisms. The expression of STR gene can greatly influence the production of many compounds. STR is mainly applied to product various valuable drugs in plant cell suspension culture and biosynthesis in other carriers.
Alkaloids/biosynthesis* ; Carbolines/metabolism* ; Carbon-Nitrogen Lyases ; Indoles/metabolism* ; Terpenes/metabolism*