1.The mechanism of Laggerae Herba in improving chronic heart failure by inhibiting ferroptosis through the Nrf2/SLC7A11/GPX4 signaling pathway
Jinling XIAO ; Kai HUANG ; Xiaoqi WEI ; Xinyi FAN ; Wangjing CHAI ; Jing HAN ; Kuo GAO ; Xue YU ; Fanghe LI ; Shuzhen GUO
Journal of Beijing University of Traditional Chinese Medicine 2025;48(3):343-353
Objective:
To investigate the role and mechanism of the heat-clearing and detoxifying drug Laggerae Herba in regulating the nuclear factor-erythroid 2-related factor-2(Nrf2)/solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) signaling pathway to inhibit ferroptosis and improve chronic heart failure induced by transverse aortic arch constriction in mice.
Methods:
Twenty-four male ICR mice were divided into the sham (n=6) and transverse aortic arch constriction groups (n=18) according to the random number table method. The transverse aortic arch constriction group underwent transverse aortic constriction surgery to establish models. After modeling, the transverse aortic arch constriction group was further divided into the model, captopril, and Laggerae Herba groups according to the random number table method, with six mice per group. The captopril (15 mg/kg) and Laggerae Herba groups (1.95 g/kg) received the corresponding drugs by gavage, whereas the sham operation and model groups were administered the same volume of ultrapure water by gavage once a day for four consecutive weeks. After treatment, the cardiac function indexes of mice in each group were detected using ultrasound. The heart mass and tibia length were measured to calculate the ratio of heart weight to tibia length. Hematoxylin and eosin staining were used to observe the pathological changes in myocardial tissue. Masson staining was used to observe the degree of myocardial fibrosis. Wheat germ agglutinin staining was used to observe the degree of myocardial cell hypertrophy. Prussian blue staining was used to observe the iron deposition in myocardial tissue. An enzyme-linked immunosorbent assay was used to detect the amino-terminal pro-brain natriuretic peptide (NT-proBNP) and glutathione (GSH) contents in mice serum. Colorimetry was used to detect the malondialdehyde (MDA) content in mice serum. Western blotting was used to detect the Nrf2, GPX4, SLC7A11, and ferritin heavy chain 1 (FTH1) protein expressions in mice cardiac tissue.
Results:
Compared with the sham group, in the model group, the ejection fraction (EF) and fractional shortening (FS) of mice decreased, the left ventricular end-systolic volume (LVESV) and left ventricular end-systolic diameter (LVESD) increased, the left ventricular anterior wall end-systolic thickness (LVAWs) and left ventricular posterior wall end-systolic thickness (LVPWs) decreased, the ratio of heart weight to tibia length increased, the myocardial tissue morphology changed, myocardial fibrosis increased, the cross-sectional area of myocardial cells increased, iron deposition appeared in myocardial tissue, the serum NT-proBNP and MDA levels increased, the GSH level decreased, and Nrf2, GPX4, SLC7A11, and FTH1 protein expressions in cardiac tissue decreased (P<0.05). Compared with the model group, in the captopril and Laggerae Herba groups, the EF, FS, and LVAWs increased, the LVESV and LVESD decreased, the ratio of heart weight to tibia length decreased, the myocardial cells were arranged neatly, the degree of myocardial fibrosis decreased, the cross-sectional area of myocardial cells decreased, the serum NT-proBNP level decreased, and the GSH level increased. Compared with the model group, the LVPWs increased, the iron deposition in myocardial tissue decreased, the serum MDA level decreased, and Nrf2, GPX4, SLC7A11, and FTH1 protein expressions in cardiac tissue increased (P<0.05) in the Laggerae Herba group.
Conclusion
Laggerae Herba improves the cardiac function of mice with chronic heart failure caused by transverse aortic arch constriction, reduces the pathological remodeling of the heart, and reduces fibrosis. Its mechanism may be related to Nrf2/SLC7A11/GPX4 pathway-mediated ferroptosis.
2.Establishment and evaluation of an animal model of heart failure with preserved ejection fraction integrating disease and syndrome based on the "deficiency-blood stasis-toxin" pathogenesis
Xiaoqi WEI ; Xinyi FAN ; Feng JIANG ; Wangjing CHAI ; Jinling XIAO ; Fanghe LI ; Kuo GAO ; Xue YU ; Wei WANG ; Shuzhen GUO
Journal of Beijing University of Traditional Chinese Medicine 2025;48(4):501-515
Objective:
This study aimed to construct an animal model of heart failure with preserved ejection fraction (HFpEF) that integrates disease and syndrome based on the "deficiency-blood stasis-toxin" pathogenesis and to evaluate it comprehensively.
Methods:
The HFpEF mouse model was constructed using a combination of Nω-nitro-L-arginine methyl ester (L-NAME) and a high-fat diet. According to the random number table method, SPF-grade male C57BL/6J mice were randomly assigned to the control, L-NAME, high-fat diet, and model groups, 10 in each group. Comprehensive observations and data collection on macroscopic signs (e.g., fur condition, mental state, stool and urine, oral and nasal condition, paw and body condition, etc.) and cardiac function were performed after 10 and 16 weeks of model induction. Additionally, the syndrome evolution was elucidated based on diagnostic criteria for clinical syndromes of heart failure. Furthermore, pathological and molecular biological examinations of myocardial tissue were performed to assess the stability and reliability of the model.
Results:
Mice in the model group showed typical characteristics of syndrome of qi deficiency and blood stasis, as well as syndrome of internal heat accumulation, including lethargy, slow response, dull paw color and oral/nasal color, exercise intolerance, abnormal platelet activation, dry feces, and dark yellow urine. The time window for these syndromes was between 10 and 16 weeks post-modeling. Cardiac function assessments revealed severe diastolic dysfunction, concentric myocardial hypertrophy, and myocardial fibrosis in the model group. Pathological examinations showed a significantly increased collagen deposition in the myocardial interstitium, enlarged cross-sectional area of cardiomyocytes, and sparse coronary microvasculature in the model group. Molecular biological analyses indicated marked activation of the inducible nitric oxide synthase/nuclear factor kappa-light-chain-enhancer of activated B cells/NOD-like receptor family pyrin domain containing 3 inflammatory pathway and significantly elevated inflammation levels in the myocardial tissue of the model group. Although mice in the L-NAME and high-fat diet groups also showed certain manifestations of qi deficiency syndrome, the substantial cardiac damage was relatively limited compared to the control group.
Conclusion
This study has constructed an animal model of HFpEF that integrates disease and syndrome based on the "deficiency-blood stasis-toxin" pathogenesis. The macroscopic and microscopic characteristics of this model are consistent with the manifestations of syndrome of qi deficiency and blood stasis, toxin syndrome, and syndrome of internal heat accumulation. Moreover, it can stably simulate the HFpEF state and reflect phenotypic changes in human disease. This model provides a suitable experimental platform to explore the pathogenesis of HFpEF, evaluate the effectiveness of traditional Chinese medicine (TCM) treatment regimens, and promote in-depth research on TCM syndromes of heart failure.
3.Mechanism of Jiming Powder in improving mitophagy for treatment of myocardial infarction based on PINK1-Parkin pathway.
Xin-Yi FAN ; Xiao-Qi WEI ; Wang-Jing CHAI ; Kuo GAO ; Fang-He LI ; Xue YU ; Shu-Zhen GUO
China Journal of Chinese Materia Medica 2025;50(12):3346-3355
In the present study, a mouse model of coronary artery ligation was employed to evaluate the effects of Jiming Powder on mitophagy in the mouse model of myocardial infarction and elucidate its underlying mechanisms. A mouse model of myocardial infarction post heart failure was constructed by ligating the left anterior descending branch of the coronary artery. The therapeutic efficacy of Jiming Powder was assessed from multiple perspectives, including ultrasonographic imaging, hematoxylin-eosin(HE) staining, Masson staining, and serum cardiac enzyme profiling. Dihydroethidium(DHE) staining was employed to evaluate the oxidative stress levels in the hearts of mice from each group. Mitophagy levels were assessed by scanning electron microscopy and immunofluorescence co-localization. Western blot was employed to determine the levels of key proteins involved in mitophagy, including Bcl-2-interacting protein beclin 1(BECN1), sequestosome 1(SQSTM1), microtubule-associated protein 1 light chain 3 beta(LC3B), PTEN-induced putative kinase 1(PINK1), phospho-Parkinson disease protein(p-Parkin), and Parkinson disease protein(Parkin). The results demonstrated that compared with the model group, high and low doses of Jiming Powder significantly reduced the left ventricular internal diameter in systole(LVIDs) and left ventricular internal diameter in diastole(LVIDd) and markedly improved the left ventricular ejection fraction(LVEF) and left ventricular fractional shortening(LVFS), effectively improving the cardiac function in post-myocardial infarction mice. Jiming Powder effectively reduced the levels of myocardial injury markers such as creatine kinase(CK), creatine kinase isoenzyme(CK-MB), and lactate dehydrogenase(LDH), thereby protecting ischemic myocardium. HE staining revealed that Jiming Powder attenuated inflammatory cell infiltration after myocardial infarction. Masson staining indicated that Jiming Powder effectively inhibited ventricular remodeling. Western blot results showed that Jiming Powder activated the PINK1-Parkin pathway, up-regulated the protein level of BECN1, down-regulated the protein level of SQSTM1, and increased the LC3Ⅱ/LC3Ⅰ ratio to promote mitophagy. In conclusion, Jiming Powder exerts therapeutic effects on myocardial infarction by inhibiting ventricular remodeling. The findings pave the way for subsequent pharmacological studies on the active components of Jiming Powder.
Animals
;
Myocardial Infarction/physiopathology*
;
Mitophagy/drug effects*
;
Mice
;
Drugs, Chinese Herbal/administration & dosage*
;
Protein Kinases/genetics*
;
Male
;
Ubiquitin-Protein Ligases/genetics*
;
Humans
;
Disease Models, Animal
;
Mice, Inbred C57BL
;
Signal Transduction/drug effects*
4.Mechanism of Jiming Powder in inhibiting ferroptosis in treatment of myocardial infarction based on NRF2/HO-1/GPX4 pathway.
Xin-Yi FAN ; Xiao-Qi WEI ; Wang-Jing CHAI ; Fang-He LI ; Kuo GAO ; Xue YU ; Shu-Zhen GUO
China Journal of Chinese Materia Medica 2025;50(11):3108-3116
This study employed a mouse model of coronary artery ligation to assess the effect and mechanism of Jiming Powder on mitochondrial autophagy in mice with myocardial infarction. The mouse model of heart failure post-myocardial infarction was established by ligating the left anterior descending coronary artery. The pharmacological efficacy of Jiming Powder was evaluated through echocardiographic imaging, hematoxylin-eosin(HE) staining, and Masson staining. The levels of malondialdehyde(MDA), Fe~(2+), reduced glutathione(GSH), and superoxide dismutase(SOD) in heart tissues, as well as MDA immunofluorescence of heart tissues, were measured to assess lipid peroxidation and Fe~(2+) levels in the hearts of mice in different groups. Ferroptosis levels in the groups were evaluated using scanning electron microscopy and Prussian blue staining. Western blot analysis was conducted to detect the levels of key ferroptosis-related proteins, including nuclear factor erythroid 2-related factor 2(NRF2), ferritin heavy chain(FTH), glutathione peroxidase 4(GPX4), solute carrier family 7 member 11(SLC7A11), heme oxygenase 1(HO-1), and Kelch-like ECH-associated protein 1(KEAP1). The results showed that compared with the model group, both the high-and low-dose Jiming Powder groups exhibited significantly reduced left ventricular internal diameter in systole(LVIDs) and left ventricular internal diameter in diastole(LVIDd), while the left ventricular ejection fraction(EF) and left ventricular fractional shortening(FS) were significantly improved, effectively enhancing cardiac function in mice post-myocardial infarction. HE staining revealed that Jiming Powder attenuated myocardial inflammatory cell infiltration post-infarction, and Masson staining indicated that Jiming Powder effectively reduced fibrosis in the infarct margin area. Treatment with Jiming Powder reduced the levels of MDA and Fe~(2+), indicators of lipid peroxidation post-myocardial infarction, while increasing GSH and SOD levels, thus protecting ischemic myocardium. Western blot results demonstrated that Jiming Powder reduced KEAP1 protein accumulation, activated the NRF2/HO-1/GPX4 pathway, and up-regulated the protein expression of FTH and SLC7A11, exerting an inhibitory effect on ferroptosis. This study reveals that Jiming Powder exerts a therapeutic effect on myocardial infarction by inhibiting ferroptosis through the NRF2/HO-1/GPX4 pathway, providing a foundation for subsequent research on the pharmacological effects of Jiming Powder.
Animals
;
Ferroptosis/drug effects*
;
Myocardial Infarction/physiopathology*
;
NF-E2-Related Factor 2/genetics*
;
Mice
;
Drugs, Chinese Herbal/administration & dosage*
;
Male
;
Heme Oxygenase-1/genetics*
;
Phospholipid Hydroperoxide Glutathione Peroxidase/genetics*
;
Humans
;
Mice, Inbred C57BL
;
Signal Transduction/drug effects*
;
Disease Models, Animal
5.Functional chimeric perforator flap of medial femoral condyle for osteochondral and soft tissue reconstruction in hand and foot joints.
Mingwu ZHOU ; Yanfeng LI ; Yang GAO ; Kai ZHANG ; Zhiwei ZHAO ; Kuo WEI ; Jia CHEN
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(9):1106-1113
OBJECTIVE:
To evaluate the effectiveness of free medial femoral condyle (MFC) functional chimeric perforator flap (FCPF) transplantation in reconstructing joint function by repairing concomitant osteochondral defects and soft tissue defect in hand and foot joints.
METHODS:
A retrospective analysis was performed on 6 patients (5 males, 1 female; mean age of 33.4 years, range 21-56 years) with traumatic osteochondral joint defects and associated tendon, nerve, and soft tissue defects treated between January 2019 and November 2024. Defect locations included metacarpal heads (n=2), metacarpophalangeal joint (n=1), first metatarsal head (n=1), base of first proximal phalanx (n=1), and talar head (n=1), with soft tissue defects in all cases. Osteochondral defect sizes ranged from 1.5 cm×1.2 cm×0.7 cm to 4.0 cm×0.6 cm×0.6 cm, and skin defects ranged from 4 cm×3 cm to 13 cm×4 cm. The stage Ⅰ treatment included debridement, antibiotic-loaded bone cement filling of bone-cartilage defects, fracture internal fixation, and coverage with vacuum sealing drainage. Stage Ⅱ involved harvesting a free MFC- FCPF included an osteochondral flap (range of 1.5 cm×1.2 cm×0.7 cm to 4.0 cm×0.6 cm×0.6 cm), gracilis and/or semitendinosus tendon grafts (length of 4-13 cm), saphenous nerve graft (length of 3.5-4.0 cm), and a perforator skin flap (range of 6 cm×4 cm to 14 cm×6 cm), each with independent vascular supply. The flap was transplanted to reconstruct joint function. Donor sites were closed primarily or with skin grafting. Flap survival was monitored postoperatively. Radiographic assessment was used to evaluate bone/joint healing. At last follow-up, the joint function recovery was assessed.
RESULTS:
All 6 MFC-FCPF survived completely, with primary healing of wounds and donor sites. All patients were followed up 6-44 months (mean, 23.5 months). The flaps at metacarpophalangeal joint in 1 case and at ankle joint in 1 case were treated with degreasing repair because of their bulky appearance, while the other flaps had good appearance and texture. At 3 months after operation, the visual analogue scale (VAS) score for pain during joint movement of recipient site was 0-2, with an average of 0.7; at last follow-up, the VAS score of the donor site was 0-1, with an average of 0.3. According to the Paley fracture healing scoring system, the osteochondral healing of all the 6 patients was excellent. The range of motion of the metacarpophalangeal joint in 3 cases was 75%, 90%, and 100% of contralateral side respectively, the range of motion of the metatarsophalangeal joint in 2 cases was 65% and 95% of contralateral side respectively, and the range of motion of the ankle joint in 1 case was 90% of contralateral side. The hand function was evaluated as excellent in 2 cases and good in 1 case according to the upper limb function evaluation standard of the Chinese Medical Association Hand Surgery Society, and the foot function was evaluated as excellent in 2 cases and fair in 1 case according to the Maryland foot function score of 93, 91, and 69, respectively. The International Knee Documentation Committee (IKDC) score of 6 knees was 91-99, with an average of 95.2.
CONCLUSION
The free MFC-FCPF enables precise anatomical joint reconstruction with three-dimensional restoration of tendon, nerve, capsule, and soft tissue defects, effectively restoring joint function and improving quality of life.
Humans
;
Male
;
Adult
;
Female
;
Middle Aged
;
Retrospective Studies
;
Plastic Surgery Procedures/methods*
;
Soft Tissue Injuries/surgery*
;
Perforator Flap/blood supply*
;
Femur/surgery*
;
Young Adult
;
Foot Joints/injuries*
;
Treatment Outcome
6.Therapeutic effect analysis of excessive dynamic airway collapse treated by laser(13 cases)
Yue WANG ; Yongping GAO ; Lei JING ; Xiaoli LI ; Fang QIN ; Jieli ZHANG ; Kuo LIU ; Yunzhi ZHOU
China Journal of Endoscopy 2024;30(3):73-80
Objective To evaluate the safety and effectiveness of excessive dynamic airway collapse(EDAC)treated by laser.Methods 13 patients with EDAC confirmed by bronchoscopy from January 2018 to August 2022 were selected and divided into a simple EDAC group(6 cases)and an EDAC combined with tracheobronchomalacia(TBM)group(7 cases)based on whether they were combined with TBM.All patients underwent laser tracheobronchoplasty under bronchoscope.Symptoms,airway collapse,oxygenation index,modified version of British Medical Research Council dyspnoea scale(mMRC)and 6 min walking test before and after treatment were compared to evaluate the therapeutic effect.Results 13 patients underwent 17 times of laser tracheobronchoplasty with laser power of 8~15 W,and 4 patients underwent 2 times of laser tracheobronchoplasty.After treatment,the clinical symptoms of cough,sputum,shortness of breath and dyspnea were improved in all patients.1 week post-treatment,the EDAC group showed a significant improvement in airway lumen stenosis,with a significant statistical difference(P<0.05),1 month post-treatment,enhancements were observed in airway stenosis,oxygenation index,FEV1%,6-minute walk test,and mMRC,which remained stable over a 6 month follow-up.In the EDAC + TBM group,significant enhancements in airway stenosis,oxygenation index,and mMRC were noted 1 week post-treatment,with statistical significance(P<0.05).Between 8 d~6 months post-treatment,some patients exhibited a recurrence of airway stenosis,necessitating comprehensive interventions like balloon dilation,cryotherapy,and stent insertion.Local necrosis and granuloma occurred in some patients after laser therapy,and no serious complications associated with laser intervention were found in all patients.Conclusion Laser tracheobronchoplasty is a safe and effective technique for the treatment of EDAC.For patients with EDAC alone,the therapeutic effect is good,but for patients with EDAC combined with TBM,the long-term effect is not good.
7.Expression of Key Enzymes in Glucose Metabolism in Chronic Mountain Sickness and Its Correlation with Phenotype.
Yun-Mei GAO ; Guo-Xiong HAN ; Cheng-Hui XUE ; Lai-Fu FANG ; Wen-Qian LI ; Kuo SHEN ; You-Bang XIE
Journal of Experimental Hematology 2023;31(1):197-202
OBJECTIVE:
To explore the pathogenesis of erythrocytosis by detecting the key enzymes of glucose metabolism and glucose transporter in bone marrow erythrocytes of chronic mountain sickness (CMS), and analyzing its correlation with hemoglobin.
METHODS:
Twenty CMS patients hospitalized in Qinghai Provincial People's Hospital from January 2019 to December 2020 were selected as CMS group. Twenty males with leukocyte count > 3.5×109/L who had accepted bone marrow aspiration and had normal result were taken as control group. The mRNA and protein expression of key enzymes and glucose transporter in glucose metabolism in bone marrow CD71+ erythrocytes were detected by real time qPCR and Western blot, respectively. Glucose, lactic acid and 2,3-diphosphoglycerate in the bone marrow supernatant and serum were tested by ELISA. The mRNA and protein expression of key enzymes and glucose transporter, glucose, lactic acid and 2,3-diphosphoglycerate of the two groups were compared. Pearson correlation was used to analyze the correlation between key enzymes, glucose transporter in glucose metabolism in bone marrow CD71+ erythrocytes and hemoglobin.
RESULTS:
The expression of HK2, GLUT1 and GLUT2 mRNA in the CMS group were higher than those in the control group (P<0.001), while the expression of HK1, OGDH and COX5B mRNA were not different. The expression of HK2, GLUT1 and GLUT2 protein in the CMS group were higher than those in the control group (P<0.05). The levels of glucose and lactic acid in the bone marrow supernatant and serum in the CMS group were not different from those in the control group, while the level of 2,3-diphosphoglycerate was higher (P<0.001). Both HK2 and GLUT2 proteins were positively correlated with hemoglobin (r=0.511, 0.717).
CONCLUSION
CMS patients may increase glycolysis by increasing the expression of HK2, and promote the utilization of glucose through high expression of GLUT1 and GLUT2 to meet the need of energy supply.
Male
;
Humans
;
Altitude Sickness/metabolism*
;
Glucose Transporter Type 1
;
2,3-Diphosphoglycerate
;
Hemoglobins
;
Chronic Disease
;
RNA, Messenger
;
Phenotype
;
Glucose
8.The impact of extended waiting time on tumor regression after neoadjuvant chemoradiotherapy for locally advanced rectal cancer.
Kuo ZHENG ; Lu JIN ; Fu SHEN ; Xian Hua GAO ; Xiao Ming ZHU ; Guan Yu YU ; Li Qiang HAO ; Zheng LOU ; Hao WANG ; En Da YU ; Chen Guang BAI ; Wei ZHANG
Chinese Journal of Surgery 2023;61(9):777-783
Objective: To investigate the influence of extending the waiting time on tumor regression after neoadjuvant chemoradiology (nCRT) in patients with locally advanced rectal cancer (LARC). Methods: Clinicopathological data from 728 LARC patients who completed nCRT treatment at the First Affiliated Hospital, Naval Medical University from January 2012 to December 2021 were collected for retrospective analysis. The primary research endpoint was the sustained complete response (SCR). There were 498 males and 230 females, with an age (M(IQR)) of 58 (15) years (range: 22 to 89 years). Logistic regression models were used to explore whether waiting time was an independent factor affecting SCR. Curve fitting was used to represent the relationship between the cumulative occurrence rate of SCR and the waiting time. The patients were divided into a conventional waiting time group (4 to <12 weeks, n=581) and an extended waiting time group (12 to<20 weeks, n=147). Comparisons regarding tumor regression, organ preservation, and surgical conditions between the two groups were made using the t test, Wilcoxon rank sum test, or χ2 test as appropriate. The Log-rank test was used to elucidate the survival discrepancies between the two groups. Results: The SCR rate of all patients was 21.6% (157/728). The waiting time was an independent influencing factor for SCR, with each additional day corresponding to an OR value of 1.010 (95%CI: 1.001 to 1.020, P=0.031). The cumulative rate of SCR occurrence gradually increased with the extension of waiting time, with the fastest increase between the 9th to <10th week. The SCR rate in the extended waiting time group was higher (27.9%(41/147) vs. 20.0%(116/581), χ2=3.901, P=0.048), and the organ preservation rate during the follow-up period was higher (21.1%(31/147) vs. 10.7%(62/581), χ2=10.510, P=0.001). The 3-year local recurrence/regrowth-free survival rates were 94.0% and 91.1%, the 3-year disease-free survival rates were 76.6% and 75.4%, and the 3-year overall survival rates were 95.6% and 92.2% for the conventional and extended waiting time groups, respectively, with no statistical differences in local recurrence/regrowth-free survival, disease-free survival and overall survival between the two groups (χ2=1.878, P=0.171; χ2=0.078, P=0.780; χ2=1.265, P=0.261). Conclusions: An extended waiting time is conducive to tumor regression, and extending the waiting time to 12 to <20 weeks after nCRT can improve the SCR rate and organ preservation rate, without increasing the difficulty of surgery or altering the oncological outcomes of patients.
9.Highly efficient production of L-valine by multiplex metabolic engineering of Corynebacterium glutamicum.
Kuo ZHAO ; Jinyu CHENG ; Liang GUO ; Cong GAO ; Wei SONG ; Jing WU ; Jia LIU ; Yadi LIU ; Liming LIU ; Xiulai CHEN
Chinese Journal of Biotechnology 2023;39(8):3253-3272
As a branched chain amino acid, L-valine is widely used in the medicine and feed sectors. In this study, a microbial cell factory for efficient production of L-valine was constructed by combining various metabolic engineering strategies. First, precursor supply for L-valine biosynthesis was enhanced by strengthening the glycolysis pathway and weakening the metabolic pathway of by-products. Subsequently, the key enzyme in the L-valine synthesis pathway, acetylhydroxylate synthase, was engineered by site-directed mutation to relieve the feedback inhibition of the engineered strain. Moreover, promoter engineering was used to optimize the gene expression level of key enzymes in L-valine biosynthetic pathway. Furthermore, cofactor engineering was adopted to change the cofactor preference of acetohydroxyacid isomeroreductase and branched-chain amino acid aminotransferase from NADPH to NADH. The engineered strain C. glutamicum K020 showed a significant increase in L-valine titer, yield and productivity in 5 L fed-batch bioreactor, up to 110 g/L, 0.51 g/g and 2.29 g/(L‧h), respectively.
Valine
;
Corynebacterium glutamicum/genetics*
;
Metabolic Engineering
;
Amino Acids, Branched-Chain
;
Bioreactors
10.Mechanism of Jiming Powder in ameliorating heart failure with preserved ejection fraction based on metabolomics.
Xiao-Qi WEI ; Xin-Yi FAN ; Hai-Yin PU ; Shuai LI ; Jia-Yang TANG ; Kuo GAO ; Fang-He LI ; Xue YU ; Shu-Zhen GUO
China Journal of Chinese Materia Medica 2023;48(17):4747-4760
In this study, untargeted metabolomics was conducted using the liquid chromatography-tandem mass spectrometry(LC-MS/MS) technique to analyze the potential biomarkers in the plasma of mice with heart failure with preserved ejection fraction(HFpEF) induced by a high-fat diet(HFD) and nitric oxide synthase inhibitor(Nω-nitro-L-arginine methyl ester hydrochloride, L-NAME) and explore the pharmacological effects and mechanism of Jiming Powder in improving HFpEF. Male C57BL/6N mice aged eight weeks were randomly assigned to a control group, a model group, an empagliflozin(10 mg·kg~(-1)·d~(-1)) group, and high-and low-dose Jiming Powder(14.3 and 7.15 g·kg~(-1)·d~(-1)) groups. Mice in the control group were fed on a low-fat diet, and mice in the model group and groups with drug intervention were fed on a high-fat diet. All mice had free access to water, with water in the model group and Jiming Powder groups being supplemented with L-NAME(0.5 g·L~(-1)). Drugs were administered on the first day of modeling, and 15 weeks later, blood pressure and cardiac function of the mice in each group were measured. Heart tissues were collected for hematoxylin-eosin(HE) staining to observe pathological changes and Masson's staining to observe myocardial collagen deposition. Untargeted metabolomics analysis was performed on the plasma collected from mice in each group, and metabolic pathway analysis was conducted using MetaboAnalyst 5.0. The results showed that the blood pressure was significantly lower and the myocardial concentric hypertrophy and left ventricular diastolic dysfunction were significantly improved in both the high-dose and low-dose Jiming Powder groups as compared with those in the model group. HE and Masson staining showed that both high-dose and low-dose Jiming Powder significantly alleviated myocardial fibrosis. In the metabolomics experiment, 23 potential biomarkers were identified and eight strongly correlated metabolic pathways were enriched, including linoleic acid metabolism, histidine metabolism, alpha-linolenic acid metabolism, glycerophospholipid metabolism, purine metabolism, porphyrin and chlorophyll metabolism, arachidonic acid metabolism, and pyrimidine metabolism. The study confirmed the pharmacological effects of Jiming Powder in lowering blood pressure and ameliorating HFpEF and revealed the mechanism of Jiming Powder using the metabolomics technique, providing experimental evidence for the clinical application of Jiming Powder in treating HFpEF and a new perspective for advancing and developing TCM therapy for HFpEF.
Male
;
Mice
;
Animals
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Heart Failure/metabolism*
;
Powders
;
Stroke Volume/physiology*
;
Chromatography, Liquid
;
NG-Nitroarginine Methyl Ester/therapeutic use*
;
Mice, Inbred C57BL
;
Tandem Mass Spectrometry
;
Metabolomics
;
Biomarkers
;
Water


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