OBJECTIVE: To explore the effects and mechanisms of the C-X-C motif chemokine ligand 12/C-X-C motif chemokine receptor 4 (CXCL12/CXCR4) signaling axis on apoptosis and autophagy in SH-SY5Y neuronal cells subjected to oxygen-glucose deprivation/reperfusion (OGD/R) model in vitro. METHODS: SH-SY5Y cells were divided into the following groups: OGD/R group and non-OGD/R group, with the OGD/R group subjected to OGD/R modeling and the non-OGD/R group receiving no treatment. Cells were also divided into CXCL12⁺ and CXCL12^- groups; the CXCL12⁺ group received 0.1 mg/L exogenous recombinant CXCL12 (rhCXCL12) at reoxygenation, while the CXCL12^- group did not. Another set of cells was divided into CXCL12+AMD3100 and CXCL12 groups; the CXCL12+AMD3100 group was pretreated with 2.5 mg/L AMD3100, a CXCR4 inhibitor, for 2 hours before OGD/R and received both 2.5 mg/L AMD3100 and 0.1 mg/L rhCXCL12 at reoxygenation, whereas the CXCL12 group received rhCXCL12 only. Additionally, cells were divided into small interfering RNA CXCR4 (siCXCR4) and small interfering RNA negative control (siNC) groups; the siCXCR4 group underwent CXCR4 knockdown before OGD/R modeling and received 0.1 mg/L rhCXCL12 at reoxygenation, while the siNC group, transfected with a negative control, received the same treatment. Protein expression of autophagy-related 16 (ATG16), microtubule-associated protein 1 light chain 3 (LC3), aquaporin-3 (AQP3), and CXCR4 was detected by Western blotting. Apoptosis rate and CXCR4 expression were measured by flow cytometry. RESULTS: Compared with the non-OGD/R group, the OGD/R group showed a significantly increased apoptosis rate and markedly decreased protein expression levels of ATG16, LC3, AQP3, and CXCR4 (all P < 0.05). CXCR4 fluorescent expression was also significantly reduced, suggesting that OGD/R simultaneously affects neuronal apoptosis and autophagy while inhibiting CXCR4 and AQP3 expression in SH-SY5Y cells. Compared with the CXCL12^- group, the CXCL12⁺ group exhibited no significant change in apoptosis rate but demonstrated significantly increased protein expression of ATG16, LC3, and AQP3 (ATG16/GAPDH: 1.21±0.10 vs. 1.00±0.00; LC3/β-actin: 1.22±0.10 vs. 1.00±0.00; AQP3/β-actin: 1.26±0.04 vs. 1.00±0.00; all P < 0.05). CXCR4 expression was also significantly enhanced (fluorescence intensity: 1.19±0.05 vs. 1.00±0.00, P < 0.05), indicating that CXCL12 may promote autophagy in OGD/R-injured SH-SY5Y cells via the CXCR4/AQP3 pathway. Compared with the CXCL12 group, the CXCL12+AMD3100 group showed no significant difference in apoptosis rate but significantly lower protein levels of ATG16 and LC3 (ATG16/GAPDH: 0.75±0.08 vs. 1.00±0.00; LC3/GAPDH: 0.86±0.07 vs. 1.00±0.00; both P < 0.05), suggesting that CXCL12 induces autophagy in OGD/R SH-SY5Y cells through CXCR4. Compared with the siNC group, the siCXCR4 group showed no significant change in apoptosis rate but significantly reduced protein expression of ATG16, LC3, AQP3, and CXCR4 (ATG16/GAPDH: 0.76±0.06 vs. 1.00±0.00; LC3/GAPDH: 0.79±0.11 vs. 1.00±0.00; AQP3/GAPDH: 0.81±0.05 vs. 1.00±0.00; CXCR4/GAPDH: 0.86±0.04 vs. 1.00±0.00; all P < 0.05), indicating that CXCR4 knockdown suppresses OGD/R-induced autophagy in SH-SY5Y cells likely via AQP3. CONCLUSIONS The CXCL12/CXCR4 signaling axis can regulate OGD/R-induced autophagy in SH-SY5Y cells through AQP3 without affecting apoptosis, indicating a role for this pathway in neuronal autophagy during cerebral ischemia/reperfusion injury.
Humans ; Receptors, CXCR4/metabolism* ; Chemokine CXCL12/metabolism* ; Autophagy ; Glucose/metabolism* ; Apoptosis ; Neurons/cytology* ; Oxygen/metabolism* ; Signal Transduction ; Cell Line, Tumor ; Cell Hypoxia ; Benzylamines ; Cyclams

OBJECTIVE: To explore the association between blood glucose trajectories within 7 days of intensive care unit (ICU) admission and mortality in patients with sepsis-associated acute respiratory distress syndrome (ARDS). METHODS: Based on the MIMIC-IV database, sepsis-associated ARDS patients with daily blood glucose monitoring data within 7 days of ICU admission were selected. Blood glucose trajectories were analyzed using group-based trajectory modeling (GBTM), and the optimal number of groups was determined based on the minimum Akaike information criterion (AIC), Bayesian information criterion (BIC), average posterior probability (AvePP), odds of correct classification (OCC), and proportion of group membership (Prop). Baseline characteristics including demographics, comorbidities, severity scores, vital signs, laboratory indicators within the first 24 hours of ICU admission, and treatments were collected. Kaplan-Meier survival curves were used to compare 28-day and 1-year survival across trajectory groups. Multivariate Logistic regression was performed to evaluate the associations between glucose trajectory groups and in-hospital mortality, ICU mortality. The incidence of hypoglycemia within 7 days in the ICU was analyzed among different groups. RESULTS: A total of 3 869 patients with sepsis-associated ARDS were included, with a median age of 63.52 (52.13, 73.54) years; 59.6% (2 304/3 869) were male. Based on glucose levels within 7 days, patients were categorized into three groups: persistent hyperglycemia group (glucose maintained at 10.6-13.1 mmol/L, n = 894), moderate glucose group (7.8-8.9 mmol/L, n = 1 452), and low-normal glucose group (6.1-7.0 mmol/L, n = 1 523). There were statistically significant differences in 28-day mortality and 1-year mortality among low-normal glucose group, moderate glucose group, and persistent hyperglycemia group [28-day mortality: 11.42% (174/1 523), 19.83% (288/1 452), 25.50% (228/894), χ ² = 82.545, P < 0.001; 1-year mortality: 23.31% (355/1 523), 33.75% (490/1 452), 39.49% (353/894), χ ² = 77.376, P < 0.001]. Kaplan-Meier analysis showed that higher glucose trajectories were associated with significantly lower 28-day and 1-year cumulative survival rates (Log-rank test: χ ² were 83.221 and 85.022, both P < 0.001). There were statistically significant differences in in-hospital mortality and ICU mortality among the low-normal glucose group, moderate glucose group, and persistent hyperglycemia group [in-hospital mortality: 9.65% (147/1 523), 19.70% (286/1 452), 24.50% (219/894), χ ² = 102.020, P < 0.001; ICU mortality: 7.22% (110/1 523), 16.05% (233/1 452), 20.13% (180/894), χ ² = 93.050, P < 0.001]. Logistic regression confirmed that, using the persistent hyperglycemia group as the reference, the low-normal glucose group had significantly lower risks of in-hospital mortality and ICU mortality after multiple factor adjustment. Although the moderate glucose group showed a trend toward lower mortality, the differences were not statistically significant. Using the moderate glucose group as a reference, the low-normal glucose group had 43.1% lower in-hospital mortality [odds ratio (OR) = 0.569, 95% confidence interval (95%CI) was 0.445-0.726, P < 0.001] and 42.0% lower ICU mortality (OR = 0.580, 95%CI was 0.439-0.762, P < 0.001). There was no statistically significant difference in the incidence of hypoglycemia within 7 days of ICU admission among low-normal glucose group, moderate glucose group, and persistent hyperglycemia group [2.82% (43/1 523), 2.69% (39/1 452), 3.02% (27/894), χ ² = 0.226, P = 0.893]. CONCLUSIONS Blood glucose trajectories during ICU stay are closely associated with prognosis in patients with sepsis-associated ARDS. Persistent hyperglycemia (10.6-13.1 mmol/L) is linked to significantly higher short- and long-term mortality.
Humans ; Respiratory Distress Syndrome/etiology* ; Sepsis/blood* ; Intensive Care Units ; Male ; Female ; Middle Aged ; Blood Glucose/metabolism* ; Hospital Mortality ; Aged

In this study, araucarene diterpenes, characterized by a pimarene skeleton with a variably oxidized side chain at C-13, were investigated. A total of 16 araucarene diterpenoids and their derivatives were isolated from the woods of Agathis dammara, including 11 previously unreported compounds: dammaradione (1), dammarones D-G (2, 5, 14, 15), dammaric acids B-F (8-12), and dammarol (16). The structures of these new compounds were elucidated using high-resolution electrospray ionization mass spectroscopy (HR-ESI-MS) and one-dimensional/two-dimensional (1D/2D) nuclear magnetic resonance (NMR), while their absolute configurations were determined through the electronic circular dichroism (ECD) exciton chirality method and Snatzke's method. The hypoglycemic activity of all isolated compounds was evaluated using a transgenic zebrafish model, and a structure-activity relationship (SAR) analysis was conducted. Araucarone (3) and dammaric acid C (9), serving as representative compounds, demonstrated significant hypoglycemic effects on zebrafish. The primary mechanism involves the promotion of pancreatic β cell regeneration and glucose uptake. Specifically, these compounds enhance the differentiation of pancreatic endocrine precursor cells (PEP cells) into β cells in zebrafish.
Zebrafish ; Animals ; Diterpenes/isolation & purification* ; Insulin-Secreting Cells/cytology* ; Glucose/metabolism* ; Hypoglycemic Agents/isolation & purification* ; Molecular Structure ; Structure-Activity Relationship ; Plant Extracts/pharmacology* ; Regeneration/drug effects*

Coptis chinensis Franch. and Panax ginseng C. A. Mey. are traditional herbal medicines with millennia of documented use and broad therapeutic applications, including anti-diabetic properties. However, the synergistic effect of total alkaloids from Coptis chinensis and total ginsenosides from Panax ginseng on type 2 diabetes mellitus (T2DM) and its underlying mechanism remain unclear. The research demonstrated that the optimal ratio of total alkaloids from Coptis chinensis and total ginsenosides from Panax ginseng was 4∶1, exhibiting maximal efficacy in improving insulin resistance and gluconeogenesis in primary mouse hepatocytes. This combination demonstrated significant synergistic effects in improving glucose tolerance, reducing fasting blood glucose (FBG), the weight ratio of epididymal white adipose tissue (eWAT), and the homeostasis model assessment of insulin resistance (HOMA-IR) in leptin receptor-deficient (db/db) mice. Subsequently, a T2DM liver-specific network was constructed based on RNA sequencing (RNA-seq) experiments and public databases by integrating transcriptional properties of disease-associated proteins and protein-protein interactions (PPIs). The network recovery index (NRI) score of the combined treatment group with a 4∶1 ratio exceeded that of groups treated with individual components. The research identified that activated adenosine 5'-monophosphate-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC) signaling in the liver played a crucial role in the synergistic treatment of T2DM, as verified by western blot experiment in db/db mice. These findings demonstrate that the 4∶1 combination of total alkaloids from Coptis chinensis and total ginsenosides from Panax ginseng significantly improves insulin resistance and glucose and lipid metabolism disorders in db/db mice, surpassing the efficacy of individual treatments. The synergistic mechanism correlates with enhanced AMPK/ACC signaling pathway activity.
Animals ; Panax/chemistry* ; Ginsenosides/administration & dosage* ; Diabetes Mellitus, Type 2/metabolism* ; Mice ; Male ; Alkaloids/pharmacology* ; Coptis/chemistry* ; Drug Synergism ; Insulin Resistance ; Mice, Inbred C57BL ; Humans ; Transcriptome/drug effects* ; Blood Glucose/metabolism* ; Hypoglycemic Agents/administration & dosage* ; Drugs, Chinese Herbal/administration & dosage* ; Hepatocytes/metabolism*

Triple-negative breast cancer (TNBC) represents an aggressive breast cancer subtype with poor prognosis and limited targeted treatment options. This investigation examined the anti-cancer potential of Caerulomycin A (Cae A), a natural compound derived from marine actinomycetes, against TNBC. Cae A demonstrated selective inhibition of viability and proliferation in TNBC cell lines, including 4T1, MDA-MB-231, and MDA-MB-468, through apoptosis induction. Mechanistic analyses revealed that the compound induced sustained endoplasmic reticulum (ER) stress and subsequent upregulation of C/EBP homologous protein (CHOP) expression, resulting in mitochondrial damage-mediated apoptosis. Inhibition of ER stress or CHOP expression knockdown reversed mitochondrial damage and apoptosis, highlighting the essential role of ER stress and CHOP in Cae A's anti-tumor mechanism. Both oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) decreased in TNBC cells following Cae A treatment, indicating reduced mitochondrial respiratory and glycolytic capacities. This diminished energy metabolism potentially triggers ER stress and subsequent apoptosis. Furthermore, Cae A exhibited significant anti-tumor effects in the 4T1 tumor model in vivo without apparent toxicity. The compound also effectively inhibited human TNBC organoid growth. These results indicate that Cae A may serve as a potential therapeutic agent for TNBC, with its efficacy likely mediated through the disruption of glucose metabolism and the induction of ER stress-associated apoptosis.
Humans ; Endoplasmic Reticulum Stress/drug effects* ; Triple Negative Breast Neoplasms/genetics* ; Apoptosis/drug effects* ; Cell Line, Tumor ; Female ; Animals ; Glucose/metabolism* ; Mice ; Cell Proliferation/drug effects* ; Transcription Factor CHOP/genetics* ; Antineoplastic Agents/pharmacology* ; Mitochondria/metabolism* ; Mice, Inbred BALB C

Ulcerative colitis (UC) is a chronic and non-specific inflammatory bowel disease (IBD). Huanglian Ganjiang decoction (HGD), derived from ancient book Beiji Qianjin Yao Fang, has demonstrated efficacy in treating UC patients traditionally. Previous research established that the compatibility of cold herb Coptidis Rhizoma + Phellodendri Chinensis Cortex (CP) and hot herb Angelicae Sinensis Radix + Zingiberis Rhizoma (AZ) in HGD synergistically improved colitis mice. This study investigated the compatibility mechanisms through which CP and AZ regulated inflammatory balance in colitis mice. The experimental colitis model was established by administering 3% dextran sulphate sodium (DSS) to mice for 7 days, followed by CP, AZ and CPAZ treatment for an additional 7 days. M1/M2 macrophage polarization levels, glucose metabolites levels and pyruvate dehydrogenase kinase 4 (PDK4) expression were analyzed using flow cytometry, Western blot, immunofluorescence and targeted glucose metabolomics. The findings indicated that CP inhibited M1 macrophage polarization, decreased inflammatory metabolites associated with tricarboxylic acid (TCA) cycle, and suppressed PDK4 expression and pyruvate dehydrogenase (PDH) (Ser-293) phosphorylation level. AZ enhanced M2 macrophage polarization, increased lactate axis metabolite lactate levels, and upregulated PDK4 expression and PDH (Ser-293) phosphorylation level. TCA cycle blocker AG-221 and adeno-associated virus (AAV)-PDK4 partially negated CP's inhibition of M1 macrophage polarization. Lactate axis antagonist oxamate and PDK4 inhibitor dichloroacetate (DCA) partially reduced AZ's activation of M2 macrophage polarization. In conclusion, the compatibility of CP and AZ synergistically alleviated colitis in mice through M1/M2 macrophage polarization balance via PDK4-mediated glucose metabolism reprogramming. Specifically, CP reduced M1 macrophage polarization by restoration of TCA cycle via PDK4 inhibition, while AZ increased M2 macrophage polarization through activation of PDK4/lactate axis.
Animals ; Drugs, Chinese Herbal/chemistry* ; Mice ; Macrophages/immunology* ; Glucose/metabolism* ; Pyruvate Dehydrogenase Acetyl-Transferring Kinase/genetics* ; Male ; Mice, Inbred C57BL ; Humans ; Colitis/drug therapy* ; Disease Models, Animal ; Colitis, Ulcerative/drug therapy* ; Metabolic Reprogramming

Glucose oxidase (GOD) is an oxygen-consuming dehydrogenase that can catalyze the production of gluconic acid hydrogen peroxide from glucose, and its specific mechanism of action makes it promising for applications, while the low catalytic activity and poor thermostability have become the main factors limiting the industrial application of this enzyme. In this study, we used the glucose oxidase AtGOD reported with the best thermostability as the source sequence for phylogenetic analysis to obtain the GOD with excellent performance. Six genes were screened and successfully synthesized for functional validation. Among them, the glucose oxidase AhGODB derived from Aspergillus heteromorphus was expressed in Pichia pastoris and showed better thermostability and catalytic activity, with an optimal temperature of 40 ℃, a specific activity of 112.2 U/mg, and a relative activity of 47% after 5 min of treatment at 70 ℃. To improve its activity and thermal stability, we constructed several mutants by directed evolution combined with rational design. Compared with the original enzyme, the mutant T72R/A153P showcased the optimum temperature increasing from 40 to 50 ℃, the specific activity increasing from 112.2 U/mg to 166.1 U/mg, and the relative activity after treatment at 70 ℃ for 30 min increasing from 0% to 33%. In conclusion, the glucose oxidase mutants obtained in this study have improved catalytic activity and thermostability, and have potential for application.
Glucose Oxidase/chemistry* ; Enzyme Stability ; Aspergillus/genetics* ; Pichia/metabolism* ; Temperature ; Catalysis ; Fungal Proteins/metabolism* ; Hot Temperature

L-theanine is an important natural non-protein amino acid that is widely used in food and medicine. Although in previous studies, a microbial fermentation method for L-theanine without the addition of ethylamine has been developed, the conversion rate of this process needs to be further improved. In this study, we constructed a de novo synthesis pathway of L-theanine with glucose as the substrate. First, an in vitro transformation pathway containing ω-transaminase (TA) and γ-glutamylmethylamide synthetase (GMAS) was designed, optimized, and introduced into the chassis strain Escherichia coli K12 W3110 to achieve de novo synthesis of L-theanine. To improve the synthesis efficiency through metabolic engineering, we increased the copies of the GMAS gene gams and the TA gene spuC and enhanced the expression of the aldehyde dehydrogenase gene eutE to provide sufficient acetaldehyde substrate, knocked out the lactate dehydrogenase gene ldhA and the pyruvate formate lyase gene pflB to block bypass metabolism, and introduced the alanine dehydrogenase gene alD to recycle alanine. Furthermore, we over-expressed the phosphoenolpyruvate carboxylase gene ppc to enhance the carbon flux of the TCA cycle, knocked out the succinyl-CoA synthase gene sucCD to reduce the loss of downstream flux of TCA, and integrated the glutamate dehydrogenase gene gdh to enhance the supply of L-glutamate. Finally, the polyphosphate kinase gene ppk was introduced to the ATP cycle, which enhanced the energy supply in L-theanine production. The recombinant strain Tea11 produced 22.60 g/L L-theanine in a 5 L fermenter in 28 h, with a conversion rate of 41.71%. This synthetic pathway in this study balanced the relationship between the supply of ethylamine and the production of theanine, providing a new idea for metabolic engineering of microorganisms to produce L-theanine.
Glutamates/biosynthesis* ; Metabolic Engineering/methods* ; Escherichia coli/genetics* ; Fermentation ; Transaminases/metabolism* ; Amide Synthases/metabolism* ; Glucose/metabolism*

L-valine is an important essential branched-chain amino acid widely used in industries such as feed, pharmaceuticals, and food. In order to further enhance the production performance of L-valine, this study systematically engineered the metabolism of a Corynebacterium glutamicum strain, preserved in the laboratory, which is capable of producing L-valine. First, strain VH-9 was obtained by enhancing the precursor supply, synthesis pathway, and transport system of L-valine. In a 5 L fermenter, the titer, yield, and productivity of L-valine were 76.6 g/L, 0.45 g/g, and 2.39 g/(L·h), respectively. Furthermore, strain VH-18 was obtained by enhancing the uptake of substrate glucose and balancing energy supply to reduce succinate accumulation, with the titer, yield, and productivity of L-valine increased to 82.7 g/L, 0.52 g/g, and 2.58 g/(L·h), respectively. After optimization of fermentation conditions, the titer, yield, and productivity of L-valine in strain VH-18 were further improved to 88.7 g/L, 0.54 g/g, and 2.77 g/(L·h), respectively. This study has achieved the high-efficiency production of L-valine through a systems metabolic engineering strategy.
Corynebacterium glutamicum/genetics* ; Metabolic Engineering/methods* ; Valine/biosynthesis* ; Fermentation ; Glucose/metabolism*

L-phosphinothricin (L-PPT) is an efficient broad-spectrum herbicide. To realize the multi-enzyme catalytic preparation of L-PPT, we constructed an engineered strain Escherichia coli YM-1 for efficient expression of D-amino acid transaminase, which could catalyze the generation of the intermediate 2-oxo-4-[(hydroxymethylphosphonyl)] butyric acid (PPO) from D-phosphinothricin (D-PPT). In addition, E. coli pLS was constructed to co-express glutamate dehydrogenase and glucose dehydrogenase, which not only catalyzed the generation of L-PPT from PPO but also regenerated the coenzyme nicotinamide adenine dinucleotide phosphate (NADPH). A fed-batch fermentation process was then established for E. coli YM-1 and pLS, and the apparent activities of D-amino acid transaminase and glutamate dehydrogenase were increased by 22.68% and 100.82%, respectively, compared with those in shake flasks. The process parameters were optimized for the catalytic preparation of L-PPT by whole-cell cascade of E. coli YM-1 and pLS with D, L-PPT as the substrate. After reaction for 8 h, 91.36% conversion of D-PPT was achieved, and the enantiomeric excess of L-PPT reached 90.22%. The findings underpin the industrial production of L-PPT.
Escherichia coli/enzymology* ; Aminobutyrates/metabolism* ; Glutamate Dehydrogenase/biosynthesis* ; Glucose 1-Dehydrogenase/biosynthesis* ; Herbicides/metabolism* ; Multienzyme Complexes/metabolism* ; Transaminases/metabolism* ; Phosphinic Acids/metabolism*