1.Effect and mechanism of Biejiajian Pill on subcutaneous xenograft tumor model of hepatocellular carcinoma Huh7 cells
Lu LU ; Huanling CHEN ; Jian XU ; Yuanqin DU ; Xiaoli LIU ; Yingsheng WU ; Chengting WU ; Wei BAN ; Jingjing HUANG ; Hongna HUANG
Journal of Clinical Hepatology 2026;42(1):125-133
ObjectiveTo investigate the inhibitory effect of Biejiajian Pills (BJJW) on the growth of liver cancer, as well as its potential mechanism in mediating the AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway through mitochondrial energy metabolism. MethodsHuman hepatoma Huh7 cells were used to establish a nude mouse model of subcutaneous xenograft tumor. A total of 18 tumor-bearing nude mice were randomly divided into model group, BJJW group (2.2 g/kg), and metformin group (250 mg/kg), and the corresponding drug was given by gavage for 14 consecutive days. Tumor volume and weight were monitored during the experiment; HE staining was used to observe histopathological changes; the levels of reactive oxygen species (ROS) and adenosine triphosphate (ATP) in tumor tissue were measured; immunohistochemistry and Western blotting were used to measure the expression levels of proteins associated with the AMPK/mTOR pathway. A one-way analysis of variance was used for comparison of normally distributed continuous data between multiple groups, and the Tukey’s test was used for further comparison between two groups; the Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data between multiple groups, and the Dunn’s test was used for further comparison between two groups. ResultsCompared with the model group, the BJJW group had a tumor inhibition rate of 45.73%, with significant reductions in both tumor volume and weight (P<0.01). Pathological examination showed that compared with the model group, the BJJW group had a significant reduction in the number of tumor cells and the presence of extensive necrosis. Mechanistic studies showed that compared with the model group, the BJJW group had a significant increase in ROS level (P<0.001) and a significant reduction in ATP level (P<0.001), as well as significant increases in p-AMPK/AMPK ratio (0.81±0.20 vs 0.13±0.04, P<0.01) and p-ULK1/ULK1 ratio (0.69±0.17 vs 0.18±0.13, P<0.01) and a significant reduction in p-mTOR/mTOR ratio (1.34±0.16 vs 3.20±0.62, P<0.01). ConclusionBJJW may inhibit the growth of liver cancer by inducing mitochondrial energy metabolism dysfunction, increasing the level of ROS, reducing the level of ATP, and activating the AMPK/mTOR signaling pathway.
2.Two cases of rare K phenotype caused by the KEL c.715G>T mutation
Jing LI ; Jing ZHANG ; Zhixia CHENG ; Jian DU ; Xiaoling ZHANG
Chinese Journal of Blood Transfusion 2026;39(4):526-533
Objective: To investigate the serological identification and blood group gene sequencing analysis of two rare cases of K
phenotype producing high-frequency antigen antibodies (anti-Ku), and to study the serological interrelationship between K
cells and the high-frequency antigen antibody anti-KL. Methods: Serological methods were used to identify the antigen phenotypes of the ABO, Rh, and Kell blood group systems and to screen for and identify unexpected antibodies in the two patients. The characteristics of the unexpected antibodies were verified by the indirect antiglobulin test (IAT) using papain or dithiothreitol (DTT) -treated screening cells. The titer of anti-Ku was determined via the tube method using DTT-treated plasma. The Kell blood group genotype was determined by gene sequencing. The distinctive antigenicity of K
cells was validated through their reactivity with anti-KL in IAT, and absorption-elution techniques were employed to corroborate the type of anti-KL. Results: Serological findings: Case 1 was blood group O, CCDee; Case 2 was blood group A, CCDee. Both cases exhibited the Kell phenotype: K-k-, Kp (a-b-). High-frequency antigen antibodies were detected in the plasma of both patients. The reactivity of these antibodies was slightly enhanced with papain-treated screening cells but became negative with DTT-treated cells. The anti-Ku (IgG) titer for Case 1 was 64. For Case 2, the anti-Ku (IgM) titer was<1, and the anti-Ku (IgG) titer was 32. Gene sequencing revealed that both cases harbored a homozygous c.715G>T mutation in the KEL gene, corresponding to the genotype KEL02N.24, consistent with the rare K
phenotype. The unique high expression of the Kx antigen on K
cells was confirmed through the antibody characteristics of anti-KL. Absorption-elution techniques demonstrated that K
cells could separate anti-Km and anti-Kx, thereby supporting the classification of anti-KL. Conclusion: Serological and molecular biological assays identified both patients as having the rare Kell-null (K
) phenotype. If such rare blood types go undetected in transfusion medicine, the administration of standard blood products can readily induce the production of high-frequency antigen antibodies such as anti-Ku, potentially leading to a transfusion crisis due to the subsequent difficulty in finding compatible blood. The serological relationship between K
cells and anti-KL clarified the characteristic high expression of the Kx antigen on K
phenotype erythrocytes and concurrently supported the typological features of the rare high-frequency antibody anti-KL. This represents the first such verified report in China.
3.Electroacupuncture Ameliorates NLRP3-mediated Pyroptosis in Spinal Cord Injury Rats by Reshaping The Gut Microbiota
Yin-Jie CUI ; Hong-Ru LI ; Jing-Yi LIU ; Hai-Lin DU ; Shu-Wen LIU ; Yuan YANG ; Chen-Guang ZHENG ; Jian-Qin XIANG ; Xiao-Juan SONG
Progress in Biochemistry and Biophysics 2026;53(5):1132-1153
ObjectiveSpinal cord injury (SCI) directly impairs the regulatory function of the autonomic nervous system, induces intestinal dysfunction, and significantly reduces patients’ quality of life. Preclinical studies have shown that electroacupuncture (EA) therapy can regulate the brain-gut axis and is used to treat central nervous system diseases such as major depressive disorder, Alzheimer’s disease and Parkinson’s disease. Recent research has established that fecal microbiota transplantation (FMT) from EA-treated SCI rats restored intestinal motility and colonic morphology. However, it remains unclear whether the regulation of gut microbiota by EA therapy directly contributes to neural repair after SCI. This study aims to explore whether gut microbiota mediates the neuroprotective effect of EA in the treatment of SCI and its possible mechanism. MethodsThe study employed RNA transcriptome analysis of spinal cord tissue to characterize gene expression profiles and to identify key signaling pathways following EA treatment for SCI. Hematoxylin-Eosin (HE) staining and Nissl staining were used to observe the morphological changes in spinal cord tissue. Western blot (WB) and enzyme-linked immunosorbent assay (ELISA) were applied to detect the effects of EA on the expression of proteins related to nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3 (NLRP3) -dependent pyroptosis. Using 16S rDNA sequencing, the study observed alterations in gut microbiota diversity and community composition in SCI rats. Prior to establishing SCI models, rats were pretreated with an antibiotic cocktail to induce gut dysbiosis, and the effects on intestinal function and spinal cord neural repair were evaluated. FMT was performed to investigate the regulatory effects of post-EA FMT on motor function, general status, liver and spleen indices, and NLRP3-mediated pyroptosis in SCI rats. ResultsEA improved motor function and reduced regulated neuronal cell death in SCI rats. Transcriptomic analysis demonstrated the activation of immune- and inflammation-related pathways post-SCI, including NOD-like receptors, nuclear factor-kappa B(NF-κB), and Toll-like receptor (TLR) pathways. EA primarily influenced intestinal inflammation and autoimmune functions. 16S rDNA sequencing illustrated that EA did not alter the diversity of gut microbiota. However, EA altered the gut microbiota composition in SCI rats, increasing Lactobacillus and Akkermansia genera while rebalancing the Firmicutes/Bacteroidetes ratio. Furthermore, depletion of gut microbiota by antibiotics disrupted the intestinal barrier, reduced the expression of intestinal barrier proteins Zonula Occludens-1 (ZO-1) and Occludin, elevated serum lipopolysaccharide-binding protein (LBP) levels, exacerbated spinal cord tissue damage, and hindered motor function recovery in SCI rats. FMT from donors treated with EA reduced LBP levels in the intestine, blood, and spinal cord of rats, inhibited the TLR4 myeloid differentiation primary response protein 88 (MyD88)-NF‑κB pathway and NLRP3-dependent pyroptosis, and improved motor function. On the other hand, FMT treatment resulted in decreased body weight and food intake, whereas FMT using EA-treated donors effectively alleviated these alterations. ConclusionEA effectively alleviated neuroinflammatory responses in rats with SCI, primarily through regulating the gut microbiota and suppressing the NLRP3-dependent pyroptosis signaling pathway.
4.Electroacupuncture Ameliorates NLRP3-mediated Pyroptosis in Spinal Cord Injury Rats by Reshaping The Gut Microbiota
Yin-Jie CUI ; Hong-Ru LI ; Jing-Yi LIU ; Hai-Lin DU ; Shu-Wen LIU ; Yuan YANG ; Chen-Guang ZHENG ; Jian-Qin XIANG ; Xiao-Juan SONG
Progress in Biochemistry and Biophysics 2026;53(5):1132-1153
ObjectiveSpinal cord injury (SCI) directly impairs the regulatory function of the autonomic nervous system, induces intestinal dysfunction, and significantly reduces patients’ quality of life. Preclinical studies have shown that electroacupuncture (EA) therapy can regulate the brain-gut axis and is used to treat central nervous system diseases such as major depressive disorder, Alzheimer’s disease and Parkinson’s disease. Recent research has established that fecal microbiota transplantation (FMT) from EA-treated SCI rats restored intestinal motility and colonic morphology. However, it remains unclear whether the regulation of gut microbiota by EA therapy directly contributes to neural repair after SCI. This study aims to explore whether gut microbiota mediates the neuroprotective effect of EA in the treatment of SCI and its possible mechanism. MethodsThe study employed RNA transcriptome analysis of spinal cord tissue to characterize gene expression profiles and to identify key signaling pathways following EA treatment for SCI. Hematoxylin-Eosin (HE) staining and Nissl staining were used to observe the morphological changes in spinal cord tissue. Western blot (WB) and enzyme-linked immunosorbent assay (ELISA) were applied to detect the effects of EA on the expression of proteins related to nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3 (NLRP3) -dependent pyroptosis. Using 16S rDNA sequencing, the study observed alterations in gut microbiota diversity and community composition in SCI rats. Prior to establishing SCI models, rats were pretreated with an antibiotic cocktail to induce gut dysbiosis, and the effects on intestinal function and spinal cord neural repair were evaluated. FMT was performed to investigate the regulatory effects of post-EA FMT on motor function, general status, liver and spleen indices, and NLRP3-mediated pyroptosis in SCI rats. ResultsEA improved motor function and reduced regulated neuronal cell death in SCI rats. Transcriptomic analysis demonstrated the activation of immune- and inflammation-related pathways post-SCI, including NOD-like receptors, nuclear factor-kappa B(NF-κB), and Toll-like receptor (TLR) pathways. EA primarily influenced intestinal inflammation and autoimmune functions. 16S rDNA sequencing illustrated that EA did not alter the diversity of gut microbiota. However, EA altered the gut microbiota composition in SCI rats, increasing Lactobacillus and Akkermansia genera while rebalancing the Firmicutes/Bacteroidetes ratio. Furthermore, depletion of gut microbiota by antibiotics disrupted the intestinal barrier, reduced the expression of intestinal barrier proteins Zonula Occludens-1 (ZO-1) and Occludin, elevated serum lipopolysaccharide-binding protein (LBP) levels, exacerbated spinal cord tissue damage, and hindered motor function recovery in SCI rats. FMT from donors treated with EA reduced LBP levels in the intestine, blood, and spinal cord of rats, inhibited the TLR4 myeloid differentiation primary response protein 88 (MyD88)-NF‑κB pathway and NLRP3-dependent pyroptosis, and improved motor function. On the other hand, FMT treatment resulted in decreased body weight and food intake, whereas FMT using EA-treated donors effectively alleviated these alterations. ConclusionEA effectively alleviated neuroinflammatory responses in rats with SCI, primarily through regulating the gut microbiota and suppressing the NLRP3-dependent pyroptosis signaling pathway.
5.Effect of Biejia Decoction Pill on aerobic glycolysis in hepatocellular carcinoma by regulating the protein kinase B/mammalian target of rapamycin signaling pathway
Qinwen TAN ; Jingjing HUANG ; Ruixi ZHONG ; Yuanqin DU ; Jian XU ; Jinli NONG ; Yujiao PENG
Journal of Clinical Hepatology 2025;41(2):300-306
ObjectiveTo investigate the inhibitory effect of Biejia Decoction Pill on the proliferation, migration, and aerobic glycolysis of hepatocellular carcinoma (HCC) using cell experiments, as well as related mechanisms. MethodsHuman liver cancer cell line Huh7 was selected, and Sprague-Dawley rats were randomly divided into blank serum group, inhibitor group, and high-, middle-, and low-dose Biejia Decoction Pill groups. Rat serum containing the drug was prepared for the incubation of Huh7 cells. CCK8 assay and scratch assay were used to explore the effect of Biejia Decoction Pill on the proliferation and migration of HCC cells; glycolytic rate-limiting enzymes and metabolites were measured to explore the effect of Biejia Decoction Pill on aerobic glycolysis of liver cancer cells; RT-qPCR and Western blot were used to explore the effect of Biejia Decoction Pill on the mRNA expression, related proteins, and phosphorylation of the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway. A one-way analysis of variance was used for comparison between multiple groups, and the least significant difference t-test or the Dunnett’s T3 test were used for further comparison between two groups. ResultsCompared with the blank serum group, the Biejia Decoction Pill groups had significant reductions in OD value, migration rate during different periods of time, glycolytic rate-limiting enzymes (hexokinase, phosphofructokinase, pyruvate kinase), and glycolytic metabolites (pyruvate, lactic acid, ATP) (all P<0.05). RT-qPCR results showed that compared with the blank serum group, the high-, middle-, and low-dose Biejia Decoction Pill groups had a significant reduction in the mRNA expression level of mTOR, and the high- and low-dose Biejia Decoction Pill groups had a significant reduction in the mRNA expression level of AKT (all P<0.05). Western blot results showed that compared with the blank serum group, the high-, middle-, and low-dose Biejia Decoction Pill groups had significant reductions in the expression levels of mTOR-related proteins and phosphorylated proteins, and the high- and middle-dose Biejia Decoction Pill groups had significant reductions in the expression levels of AKT-related proteins and phosphorylated proteins (all P<0.05). ConclusionThis study preliminarily verifies that the serum containing Bijia Decoction Pill can inhibit the aerobic glycolysis of human hepatoma Huh7 cells, thereby inhibiting their proliferation and migration, possibly by inhibiting the expression of the proteins related to the AKT/mTOR signaling pathway.
6.Antithrombotic effect in zebrafish of a fibrinolytic protein EPF3 from Dilong (Pheretima vulgaris Chen) and its transport mechanism in Caco-2 monolayer through cell bypass pathway.
Wan-Ling ZHONG ; Jian-Qiong YANG ; Hai LIU ; Ya-Li WU ; Hui-Juan SHEN ; Peng-Yue LI ; Shou-Ying DU
Journal of Integrative Medicine 2025;23(4):415-428
OBJECTIVE:
EPF3 is a fibrinolysin monomer isolated and purified from Pheretima vulgaris Chen, an earthworm used in traditional Chinese medicine as Dilong for treating blood stasis syndrome. Its composition, anticoagulant and fibrinolytic activities, and relevant mechanisms have been confirmed through in vitro experiments. However, whether it has antithrombotic effects in vivo and can be absorbed by the gastrointestinal tract is unknown. This study evaluates the antithrombotic effect in zebrafish and investigates the gastrointestinal stability and intestinal absorption mechanism of this protein in vitro.
METHODS:
The antithrombotic effect of EPF3 in vivo was verified using the zebrafish thrombus model induced by arachidonic acid and FeCl3. Then, the protein bands of EPF3 incubated with simulated gastric fluid (SGF), simulated intestinal fluid (SIF), and homogenate of Caco-2 cells (HC2C) were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to evaluate its gastrointestinal stability. Finally, the transport behavior and absorption mechanism of EPF3 were studied using Caco-2 cell monolayer.
RESULTS:
EPF3 could significantly enhance the returned blood volume and blood flow velocity in zebrafish with platelet aggregation thrombus induced by arachidonic acid. It could also prolong the formation time of tail artery thrombus and increase the blood flow velocity in zebrafish with vessel injury thrombus induced by FeCl3. EPF3 was stable in SIF and HC2C and unstable in SGF. The permeability of EPF3 in Caco-2 monolayer was time-dependent and concentration-dependent. The efflux ratio was less than 1.2 during transport, and the transport behavior was not affected by inhibitors. EPF3 could reversibly reduce the expression of tight junction-related proteins, including zonula occludens-1, occludin, and claudin-1 in Caco-2 cells.
CONCLUSION
EPF3 could play a thrombolytic and antithrombotic role in zebrafish. It could be transported and absorbed into the intestine through cellular bypass pathway by opening the intestinal epithelium tight junction. This study provides a scientific explanation for the antithrombotic effect of earthworm and provides a basis for the feasibility of subsequent development of EPF3 as an antithrombotic enteric-soluble preparation. Please cite this article as: Zhong WL, Yang JQ, Liu H, Wu YL, Shen HJ, Li PY, Du SY. Antithrombotic effect in zebrafish of a fibrinolytic protein EPF3 from Dilong (Pheretima vulgaris Chen) and its transport mechanism in Caco-2 monolayer through cell bypass pathway. J Integr Med. 2025; 23(4): 415-428.
Animals
;
Zebrafish
;
Humans
;
Caco-2 Cells
;
Fibrinolytic Agents/pharmacology*
;
Thrombosis/drug therapy*
;
Intestinal Absorption
7.Baicalein attenuates lipopolysaccharide-induced myocardial injury by inhibiting ferroptosis via miR-299b-5p/HIF1-α pathway.
Wen-Yan ZHOU ; Jian-Kui DU ; Hong-Hong LIU ; Lei DENG ; Kai MA ; Jian XIAO ; Sheng ZHANG ; Chang-Nan WANG
Journal of Integrative Medicine 2025;23(5):560-575
OBJECTIVE:
Baicalein has been reported to have wide therapeutic effects that act through its anti-inflammatory activity. This study examines the effect and mechanism of baicalein on sepsis-induced cardiomyopathy (SIC).
METHODS:
A thorough screening of a small library of natural products, comprising 100 diverse compounds, was conducted to identify the most effective drug against lipopolysaccharide (LPS)-treated H9C2 cardiomyocytes. The core target proteins and their associated signaling pathways involved in baicalein's efficacy against LPS-induced myocardial injury were predicted by network pharmacology.
RESULTS:
Baicalein was identified as the most potent protective agent in LPS-exposed H9C2 cardiomyocytes. It exhibited a dose-dependent inhibitory effect on cell injury and inflammation. In the LPS-induced septic mouse model, baicalein demonstrated a significant capacity to mitigate LPS-triggered myocardial deficits, inflammatory responses, and ferroptosis. Network pharmacological analysis and experimental confirmation suggested that hypoxia-inducible factor 1 subunit α (HIF1-α) is likely to be the crucial factor in mediating the impact of baicalein against LPS-induced myocardial ferroptosis and injury. By combining microRNA (miRNA) screening in LPS-treated myocardium with miRNA prediction targeting HIF1-α, we found that miR-299b-5p may serve as a regulator of HIF1-α. The reduction in miR-299b-5p levels in LPS-treated myocardium, compared to the control group, was reversed by baicalein treatment. The reverse transcription quantitative polymerase chain reaction, Western blotting, and dual-luciferase reporter gene analyses together identified HIF1-α as the target of miR-299b-5p in cardiomyocytes.
CONCLUSION
Baicalein mitigates SIC at the miRNA level, suggesting the therapeutic potential of it in treating SIC through the regulation of miR-299b-5p/HIF1-α/ferroptosis pathway. Please cite this article as: Zhou WY, Du JK, Liu HH, Deng L, Ma K, Xiao J, Zhang S, Wang CN. Baicalein attenuates lipopolysaccharide-induced myocardial injury by inhibiting ferroptosis via miR-299b-5p/HIF1-α pathway. J Integr Med. 2025; 23(5):560-575.
Flavanones/pharmacology*
;
Animals
;
MicroRNAs/genetics*
;
Lipopolysaccharides
;
Hypoxia-Inducible Factor 1, alpha Subunit/genetics*
;
Ferroptosis/drug effects*
;
Mice
;
Myocytes, Cardiac/metabolism*
;
Signal Transduction/drug effects*
;
Rats
;
Male
;
Mice, Inbred C57BL
;
Cardiomyopathies/etiology*
;
Cell Line
;
Sepsis/complications*
8.Association between PM 2.5 Chemical Constituents and Preterm Birth: The Undeniable Role of Preconception H19 Gene Variation.
Ya Long WANG ; Pan Pan SUN ; Xin Ying WANG ; Jun Xi ZHANG ; Xiang Yu YU ; Jian CHAI ; Ruo DU ; Wen Yi LIU ; Fang Fang YU ; Yue BA ; Guo Yu ZHOU
Biomedical and Environmental Sciences 2025;38(8):1016-1022
9.Association of Body Mass Index with All-Cause Mortality and Cause-Specific Mortality in Rural China: 10-Year Follow-up of a Population-Based Multicenter Prospective Study.
Juan Juan HUANG ; Yuan Zhi DI ; Ling Yu SHEN ; Jian Guo LIANG ; Jiang DU ; Xue Fang CAO ; Wei Tao DUAN ; Ai Wei HE ; Jun LIANG ; Li Mei ZHU ; Zi Sen LIU ; Fang LIU ; Shu Min YANG ; Zu Hui XU ; Cheng CHEN ; Bin ZHANG ; Jiao Xia YAN ; Yan Chun LIANG ; Rong LIU ; Tao ZHU ; Hong Zhi LI ; Fei SHEN ; Bo Xuan FENG ; Yi Jun HE ; Zi Han LI ; Ya Qi ZHAO ; Tong Lei GUO ; Li Qiong BAI ; Wei LU ; Qi JIN ; Lei GAO ; He Nan XIN
Biomedical and Environmental Sciences 2025;38(10):1179-1193
OBJECTIVE:
This study aimed to explore the association between body mass index (BMI) and mortality based on the 10-year population-based multicenter prospective study.
METHODS:
A general population-based multicenter prospective study was conducted at four sites in rural China between 2013 and 2023. Multivariate Cox proportional hazards models and restricted cubic spline analyses were used to assess the association between BMI and mortality. Stratified analyses were performed based on the individual characteristics of the participants.
RESULTS:
Overall, 19,107 participants with a sum of 163,095 person-years were included and 1,910 participants died. The underweight (< 18.5 kg/m 2) presented an increase in all-cause mortality (adjusted hazards ratio [ aHR] = 2.00, 95% confidence interval [ CI]: 1.66-2.41), while overweight (≥ 24.0 to < 28.0 kg/m 2) and obesity (≥ 28.0 kg/m 2) presented a decrease with an aHR of 0.61 (95% CI: 0.52-0.73) and 0.51 (95% CI: 0.37-0.70), respectively. Overweight ( aHR = 0.76, 95% CI: 0.67-0.86) and mild obesity ( aHR = 0.72, 95% CI: 0.59-0.87) had a positive impact on mortality in people older than 60 years. All-cause mortality decreased rapidly until reaching a BMI of 25.7 kg/m 2 ( aHR = 0.95, 95% CI: 0.92-0.98) and increased slightly above that value, indicating a U-shaped association. The beneficial impact of being overweight on mortality was robust in most subgroups and sensitivity analyses.
CONCLUSION
This study provides additional evidence that overweight and mild obesity may be inversely related to the risk of death in individuals older than 60 years. Therefore, it is essential to consider age differences when formulating health and weight management strategies.
Humans
;
Body Mass Index
;
China/epidemiology*
;
Male
;
Female
;
Middle Aged
;
Prospective Studies
;
Rural Population/statistics & numerical data*
;
Aged
;
Follow-Up Studies
;
Adult
;
Mortality
;
Cause of Death
;
Obesity/mortality*
;
Overweight/mortality*
10.Metabolic engineering of Escherichia coli for efficient biosynthesis of L-citrulline.
Linfeng XU ; Wenwen YU ; Xuewen ZHU ; Quanwei ZHANG ; Yaokang WU ; Jianghua LI ; Guocheng DU ; Xueqin LV ; Jian CHEN ; Long LIU
Chinese Journal of Biotechnology 2025;41(1):242-255
L-citrulline is a nonprotein amino acid that plays an important role in human health and has great market demand. Although microbial cell factories have been widely used for biosynthesis, there are still challenges such as genetic instability and low efficiency in the biosynthesis of L-citrulline. In this study, an efficient, plasmid-free, non-inducible L-citrulline-producing strain of Escherichia coli BL21(DE3) was engineered by combined strategies. Firstly, a chassis strain capable of synthesizing L-citrulline was constructed by block of L-citrulline degradation and removal of feedback inhibition, with the L-citrulline titer of 0.43 g/L. Secondly, a push-pull-restrain strategy was employed to enhance the L-citrulline biosynthesis, which realized the L-citrulline titer of 6.0 g/L. Thirdly, the NADPH synthesis and L-citrulline transport were strengthened to promote the synthesis efficiency, which achieved the L-citrulline titer of 11.6 g/L. Finally, fed-batch fermentation was performed with the engineered strain in a 3 L fermenter, in which the L-citrulline titer reached 44.9 g/L. This study lays the foundation for the industrial production of L-citrulline and provides insights for the modification of other amino acid metabolic networks.
Citrulline/biosynthesis*
;
Escherichia coli/genetics*
;
Metabolic Engineering/methods*
;
Fermentation
;
NADP/biosynthesis*

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