1.Protective Effect of Xuebijing on Lung Injury in Rats with Severe Acute Pancreatitis by Blocking FPRs/NLRP3 Inflammatory Pathway
Guixian ZHANG ; Dawei LIU ; Xia LI ; Xijing LI ; Pengcheng SHI ; Zhiqiao FENG ; Jun CAI ; Wenhui ZONG ; Xiumei ZHAO ; Hongbin LIU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(1):113-120
ObjectiveTo explore the therapeutic effect of Xuebijing injection (XBJ) on severe acute pancreatitis induced acute lung injury (SAP-ALI) by regulating formyl peptide receptors (FPRs)/nucleotide-binding oligomerization domain-like receptor 3 (NLRP3) inflammatory pathway. MethodsSixty rats were randomly divided into a sham group, a SAP-ALI model group, low-, medium-, and high-dose XBJ groups (4, 8, and 12 mL·kg-1), and a positive drug (BOC2, 0.2 mg·kg-1) group. For the sham group, the pancreas of rats was only gently flipped after laparotomy, and then the abdomen was closed, while for the remaining five groups, SAP-ALI rat models were established by retrograde injection of 5% sodium taurocholate (Na-Tc) via the biliopancreatic duct. XBJ and BOC2 were administered via intraperitoneal injection once daily for 3 d prior to modeling and 0.5 h after modeling. Blood was collected from the abdominal aorta 6 h after the completion of modeling, and the expression of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) in plasma was measured by enzyme-linked immunosorbent assay (ELISA). The amount of ascites was measured, and the dry-wet weight ratios of pancreatic and lung tissue were determined. Pancreatic and lung tissue was taken for hematoxylin-eosin (HE) staining to observe pathological changes and then scored. The protein expression levels of FPR1, FPR2, and NLRP3 in lung tissue were detected by the immunohistochemical method. Western blot was used to detect the expression of FPR1, FPR2, and NLRP3 in lung tissue. Real-time fluorescence quantitative polymerase chain reaction (Real-time PCR) was used to detect the mRNA expression of FPR1, FPR2, and NLRP3 in lung tissue. ResultsCompared with the sham group, the SAP-ALI model group showed significantly decreased dry-wet weight ratio of lung tissue (P<0.01), serious pathological changes of lung tissue, a significantly increased pathological score (P<0.01), and significantly increased protein and mRNA expression levels of FPR1, FPR2, and NLRP3 in lung tissue (P<0.01). After BOC2 intervention, the above detection indicators were significantly reversed (P<0.01). After treatment with XBJ, the groups of different XBJ doses achieved results consistent with BOC2 intervention. ConclusionXBJ can effectively improve the inflammatory response of the lungs in SAP-ALI rats and reduce damage. The mechanism may be related to inhibiting the expression of FPRs and NLRP3 in lung tissue, which thereby reduces IL-1β and simultaneously antagonize the release of inflammatory factors IL-6 and TNF-α.
2.Objective characteristics of tongue manifestation in different stages of damp-heat syndrome in diabetic kidney disease
Zhaoxi DONG ; Yang SHI ; Jiaming SU ; Yaxuan WEN ; Zheyu XU ; Xinhui YU ; Jie MEI ; Fengyi CAI ; Xinyue ZANG ; Yan GUO ; Chengdong PENG ; Hongfang LIU
Journal of Beijing University of Traditional Chinese Medicine 2025;48(3):398-411
Objective:
To investigate the objective characteristics of tongue manifestation in different stages of damp-heat syndrome in diabetic kidney disease (DKD).
Methods:
A cross-sectional study enrolled 134 patients with DKD G3-5 stages who met the diagnostic criteria for damp-heat syndrome in DKD. The patients were treated at Dongzhimen Hospital, Beijing University of Chinese Medicine, from May 2023 to January 2024. The patients were divided into three groups: DKD G3, DKD G4, and DKD G5 stage, with 53, 33, and 48 patients in each group, respectively. Clinical general data (gender, age, and body mass index) and damp-heat syndrome scores were collected from the patients. The YZAI-02 traditional Chinese medicine (TCM) AI Tongue Image Acquisition Device was used to capture tongue images from these patients. The accompanying AI Open Platform for TCM Tongue Diagnosis of the device was used to analyze and extract tongue manifestation features, including objective data on tongue color, tongue quality, coating color, and coating texture. Clinical data and objective tongue manifestation characteristics were compared among patients with DKD G3-5 based on their DKD damp-heat syndrome status.
Results:
No statistically significant difference in gender or body mass index was observed among the three patient groups. The DKD G3 stage group had the highest age (P<0.05). The DKD G3 stage group had a lower score for symptoms of poor appetite and anorexia(P<0.05) than the DKD G5 group. No statistically significant difference was observed in damp-heat syndrome scores among the three groups. Compared with the DKD G5 stage group, the DKD G3 stage group showed a decreased proportion of pale color at the tip and edges of the tongue (P<0.05). The DKD G4 stage group exhibited an increased proportion of crimson at the root of the tongue, a decreased proportion of thick white tongue coating at the root, a decreased proportion of pale color at the tip and edges of the tongue, an increased hue value (indicating color tone) of the tongue color in the middle, an increased brightness value (indicating color lightness) of the tongue coating color in the middle, and an increased thickness of the tongue coating (P<0.05). No statistically significant difference was observed in other tongue color proportions, color chroma values, body characteristics, coating color proportions, coating color chroma values, and coating texture characteristics among the three groups.
Conclusion
Tongue features differ in different stages of DKD damp-heat syndrome in multiple dimensions, enabling the inference that during the DKD G5 stage, the degree of qi and blood deficiency in the kidneys, heart, lungs, liver, gallbladder, spleen, and stomach is prominent. Dampness is more likely to accumulate in the lower jiao, particularly in the kidneys, whereas heat evil in the spleen and stomach is the most severe. These insights provide novel ideas for the clinical treatment of DKD.
3.Secular trend and projection of overweight and obesity among Chinese children and adolescents aged 7-18 years from 1985 to 2019: Rural areas are becoming the focus of investment.
Jiajia DANG ; Yunfei LIU ; Shan CAI ; Panliang ZHONG ; Di SHI ; Ziyue CHEN ; Yihang ZHANG ; Yanhui DONG ; Jun MA ; Yi SONG
Chinese Medical Journal 2025;138(3):311-317
BACKGROUND:
The urban-rural disparities in overweight and obesity among children and adolescents are narrowing, and there is a need for long-term and updated data to explain this inequality, understand the underlying mechanisms, and identify priority groups for interventions.
METHODS:
We analyzed data from seven rounds of the Chinese National Survey on Students Constitution and Health (CNSSCH) conducted from 1985 to 2019, focusing on school-age children and adolescents aged 7-18 years. Joinpoint regression was used to identify inflection points (indicating a change in the trend) in the prevalence of overweight and obesity during the study period, stratified by urban/rural areas and sex. Annual percent change (APC), average annual percent change (AAPC), and 95% confidence interval (CI) were used to describe changes in the prevalence of overweight and obesity. Polynomial regression models were used to predict the prevalence of overweight and obesity among children and adolescents in 2025 and 2030, considering urban/rural areas, sex, and age groups.
RESULTS:
The prevalence of overweight and obesity in urban boys and girls showed an inflection point of 2000, with AAPC values of 10.09% (95% CI: 7.33-12.92%, t = 7.414, P <0.001) and 8.67% (95% CI: 6.10-11.30%, t = 6.809, P <0.001), respectively. The APC for urban boys decreased from 18.31% (95% CI: 4.72-33.67%, t = 5.926, P = 0.027) to 4.01% (95% CI: 1.33-6.75%, t = 6.486, P = 0.023), while the APC for urban girls decreased from 13.88% (95% CI: 1.82-27.38%, t = 4.994, P = 0.038) to 4.72% (95% CI: 1.43-8.12%, t = 6.215, P = 0.025). However, no inflection points were observed in the best-fit models for rural boys and girls during the period 1985-2019. The prevalence of overweight and obesity for both urban and rural boys is expected to converge at 35.76% by approximately 2027. A similar pattern is observed for urban and rural girls, with a prevalence of overweight and obesity reaching 20.86% in 2025.
CONCLUSIONS
The prevalence of overweight and obesity among Chinese children and adolescents has been steadily increasing from 1985 to 2019. A complete reversal in urban-rural prevalence is expected by 2027, with a higher prevalence of overweight and obesity in rural areas. Urgent action is needed to address health inequities and increase investments, particularly policies targeting rural children and adolescents.
Humans
;
Child
;
Adolescent
;
Female
;
Male
;
Rural Population/statistics & numerical data*
;
Overweight/epidemiology*
;
Prevalence
;
China/epidemiology*
;
Pediatric Obesity/epidemiology*
;
Obesity/epidemiology*
;
Urban Population
4.International risk signal prioritization principles: comparison and implications for scientific regulation of traditional Chinese medicine.
Rui ZHENG ; Shuo LIU ; Shi-Jia WANG ; He-Rong CUI ; Hai-Bo SONG ; Hong-Cai SHANG
China Journal of Chinese Materia Medica 2025;50(1):273-277
Signal detection is a critical task in drug safety regulation. However, it inevitably generates irrelevant or false signals, posing challenges for resource allocation by marketing authorization holders. To reasonably assess these signals, different countries have established various principles for prioritizing the evaluation of risk signals. This study systematically compares these principles and finds that the U.S. Food and Drug Administration(FDA) focuses on practical issues, such as identifying drug confusion or drug interactions. However, China's Good Pharmacovigilance Practices and the European Medicines Agency(EMA) emphasize a comprehensive evaluation framework. The Council for International Organizations of Medical Sciences(CIOMS) emphasizes the consistency of multiple data sources, highlighting the reliability of signal evaluation. China practices a multidisciplinary approach combining traditional Chinese and western medicine, and the risk signals related to traditional Chinese medicine(TCM) have unique characteristics, including complex components, cumulative toxicity, specific theoretical foundations, and drug interactions. The different priorities in risk signal evaluation principles across countries suggest that China should strengthen clinical trial research, emphasize corroboration with evidence of multiple sources, and pay particular attention to the risks of drug interactions in the TCM regulatory science. Establishing the risk signal prioritization principles that align with the characteristics of TCM enables more precise and efficient scientific regulation of TCM.
Humans
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Medicine, Chinese Traditional/standards*
;
China
;
Drugs, Chinese Herbal/adverse effects*
;
United States
;
United States Food and Drug Administration
5.Proposal and research idea of "traditional Chinese medicine processing chemical biology".
Peng-Peng LIU ; Qian CAI ; Ji SHI ; Nan XU ; Hui GAO ; Ke-Wu ZENG ; Tian-Zhu JIA
China Journal of Chinese Materia Medica 2025;50(3):833-839
Traditional Chinese medicine(TCM) processing is a unique and highly distinctive pharmaceutical technology in China. Utilizing modern scientific methods to elucidate the connotations of traditional processing theory and its effects is expected to facilitate the inheritance, development, innovation, and enhancement of TCM processing, and lead to more original research outcomes in the field of TCM. The breakthrough in TCM processing lies in the study of its underlying principles, and analyzing these principles involves researching the transformation mechanisms of chemical components and the biological effect mechanisms of the transformed components. This paper proposed the concept of "TCM processing chemical biology"(TCMPCB) for the first time. Under the guidance of TCM theory, the active components transformed during TCM processing were used as chemical tools to study their targets and molecular regulatory mechanisms, aiming to clarify the scientific principles by which TCM processing affected biological effects in the organism. The research findings also provided new directions for discovering novel active components, new lead compounds, creating new decoction pieces, and developing new TCM drugs. This paper provided a detailed introduction to the background, definition, research content, research ideas, research methods, and prospects of TCMPCB, with the aim of offering new research perspectives for analyzing the principles of TCM processing and providing new pathways for achieving the "four new and eight transformations" in TCM processing.
Drugs, Chinese Herbal/chemistry*
;
Medicine, Chinese Traditional/methods*
;
Humans
;
Animals
6.Stimulation mechanism of osteoblast proliferation and differentiation by Duzhong Decoction-containing serum through L-VGCCs.
Ze-Bin CHEN ; Lan-Lan LUO ; Xin-Yi SHI ; Rui-Tong ZHAO ; Cai-Xian HU ; Yun-Ying FU ; Su-Zhen CHAO ; Bo LIU
China Journal of Chinese Materia Medica 2025;50(12):3335-3345
This paper aimed to explore the effects of Duzhong Decoction(DZD)-containing serum on the proliferation and osteoblast differentiation of MC3T3-E1 cells through L-type voltage-gated calcium channels(L-VGCCs). L-VGCCs inhibitors, nifedipine and verapamil, were used to block L-VGCCs in osteoblasts. MC3T3-E1 cells were divided into a control group, a low-dose DZD-containing serum(L-DZD) group, a medium-dose DZD-containing serum(M-DZD) group, a high-dose DZD-containing serum(H-DZD) group, a nifedipine group, a H-DZD + nifedipine group, verapamil group, and a H-DZD + verapamil group. The CCK-8 method was used for cell proliferation analysis, alkaline phosphatase(ALP) assay kits for intracellular ALP activity measurement, Western blot for protein expression level in cells, real-time fluorescence quantitative PCR technology for intracellular mRNA expression level determination, fluorescence spectrophotometer for free Ca~(2+) concentration determination in osteoblasts, and alizarin red staining(ARS) for mineralized nodule formation in osteoblasts. The experimental results show that compared to the control group, DZD groups can promote MC3T3-E1 cell proliferation, ALP activity, and mineralized nodule formation, increase intracellular Ca~(2+) concentrations, and upregulate the protein expression of bone morphogenetic protein 2(BMP2), collagen Ⅰ(COL1), α2 subunit protein of L-VGCCs(L-VGCCα2), and the mRNA expression of Runt-related transcription factor 2(RUNX2), and BMP2. After blocking L-VGCCs with nifedipine and verapamil, the intervention effects of DZD-containing serum were inhibited to varying degrees. Both nifedipine and verapamil could inhibit ALP activity, reduce mineralized nodule areas, and downregulate the expression of bone formation-related proteins. Moreover, the effects of DZD-containing serum on increasing MC3T3-E1 cell proliferation, osteoblast differentiation, and Ca~(2+) concentrations, upregulating the mRNA expression of osteoprotegerin(OPG) and protein expression of phosphorylated protein kinase B(p-Akt) and phosphorylated forkhead box protein O1(p-FOXO1), and upregulating phosphatase and tensin homolog(PTEN) expression were reversed by nifedipine. The results indicate that DZD-containing serum can increase the Ca~(2+) concentration in MC3T3-E1 cells to promote bone formation, which may be mediated by L-VGCCs and the PTEN/Akt/FoxO1 signaling pathway, providing a new perspective on the mechanism of DZD in treating osteoporosis.
Animals
;
Osteoblasts/metabolism*
;
Cell Proliferation/drug effects*
;
Cell Differentiation/drug effects*
;
Mice
;
Drugs, Chinese Herbal/pharmacology*
;
Calcium Channels, L-Type/genetics*
;
Alkaline Phosphatase/genetics*
;
Serum/chemistry*
;
Cell Line
;
Osteogenesis/drug effects*
;
Bone Morphogenetic Protein 2/genetics*
7.Effectiveness of three-dimensional-printed microporous titanium prostheses combined with flap implantation in treatment of large segmental infectious bone defects in limbs.
Yongqing XU ; Xinyu FAN ; Teng WANG ; Shaoquan PU ; Xingbo CAI ; Xiangwen SHI ; Wei LIN ; Xi YANG ; Jian LI ; Min LIU
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(5):521-528
OBJECTIVE:
To analyze the effectiveness of single three-dimensional (3D)-printed microporous titanium prostheses and flap combined prostheses implantation in the treatment of large segmental infectious bone defects in limbs.
METHODS:
A retrospective analysis was conducted on the clinical data of 76 patients with large segmental infectious bone defects in limbs who were treated between January 2019 and February 2024 and met the selection criteria. Among them, 51 were male and 25 were female, with an age of (47.7±9.4) years. Of the 76 patients, 51 had no soft tissue defects (single prostheses group), while 25 had associated soft tissue defects (flap combined group). The single prostheses group included 28 cases of tibial bone defects, 11 cases of femoral defects, 5 cases of humeral defects, 4 cases of radial bone defects, and 3 cases of metacarpal, or carpal bone defects, with bone defect length ranging from 3.5 to 28.0 cm. The flap combined group included 3 cases of extensive dorsum of foot soft tissue defects combined with large segmental metatarsal bone defects, 19 cases of lower leg soft tissue defects combined with large segmental tibial bone defects, and 3 cases of hand and forearm soft tissue defects combined with metacarpal, carpal, or radial bone defects, with bone defect length ranging from 3.8 to 32.0 cm and soft tissue defect areas ranging from 8 cm×5 cm to 33 cm×10 cm. In the first stage, vancomycin-loaded bone cement was used to control infection, and flap repair was performed in the flap combined group. In the second stage, 3D-printed microporous titanium prostheses were implanted. Postoperative assessments were performed to evaluate infection control and bone integration, and pain release was evaluated using the visual analogue scale (VAS) score.
RESULTS:
All patients were followed up postoperatively, with an average follow-up time of (35.2±13.4) months. In the 61 lower limb injury patients, the time of standing, walk with crutches, and fully bear weight were (2.2±0.6), (3.9±1.1), and (5.4±1.1) months, respectively. The VAS score at 1 year postoperatively was significantly lower than preoperative one ( t=-10.678, P<0.001). At 1 year postoperatively, 69 patients (90.8%) showed no complication such as infection, fracture, prosthesis displacement, or breakage, and X-ray films indicated good integration at the prosthesis-bone interface. According to the Paley scoring system for the healing of infectious bone defects, the results were excellent in 37 cases, good in 29 cases, fair in 3 cases, and poor in 7 cases. In the single prostheses group, during the follow-up, there was 1 case each of femoral prostheses fracture, femoral infection, and tibial infection, with a treatment success rate of 94.1% (48/51). In lower limb injury patients, the time of fully bear weight was (5.0±1.0) months. In the flap combined group, during the follow-up, 1 case of tibial fixation prostheses screw fracture occurred, along with 2 cases of recurrent foot infection in diabetic patients and 1 case of tibial infection. The treatment success rate was 84.0% (21/25). The time of fully bear weight in lower limb injury patients was (5.8±1.2) months. The overall infection eradication rate for all patients was 93.4% (71/76).
CONCLUSION
The use of 3D-printed microporous titanium prostheses, either alone or in combination with flaps, for the treatment of large segmental infectious bone defects in the limbs results in good effectiveness with a low incidence of complications. It is a feasible strategy for the reconstruction of infectious bone defects.
Humans
;
Male
;
Female
;
Middle Aged
;
Printing, Three-Dimensional
;
Titanium
;
Retrospective Studies
;
Surgical Flaps
;
Adult
;
Prosthesis Implantation/methods*
;
Plastic Surgery Procedures/methods*
;
Treatment Outcome
;
Prostheses and Implants
;
Bone Diseases, Infectious/surgery*
;
Extremities/surgery*
;
Prosthesis Design
8.Clinical Characteristics and Prognostic Analysis of Newly Diagnosed Acute Myeloid Leukemia Patients with NRAS and KRAS Gene Mutations.
Zhang-Yu YU ; Bo CAI ; Yi WANG ; Yang-Yang LEI ; Bing-Xia LI ; Yu-Fang LI ; Yan-Ping SHI ; Jia-Xin CHEN ; Shu-Hong LIU ; Chang-Lin YU ; Mei GUO
Journal of Experimental Hematology 2025;33(3):682-690
OBJECTIVE:
To retrospectively analyze the clinical characteristics, co-mutated genes in newly diagnosed acute myeloid leukemia (AML) patients with NRAS and KRAS gene mutations, and the impact of NRAS and KRAS mutations on prognosis.
METHODS:
The clinical data and next-generation sequencing results of 80 newly diagnosed AML patients treated at our hospital from December 2018 to December 2023 were collected. The clinical characteristics, co-mutated genes of NRAS and KRAS , and the impact of NRAS and KRAS mutations on prognosis in newly diagnosed AML patients were analyzed.
RESULTS:
Among 80 newly diagnosed AML patients, NRAS mutations were detected in 20 cases(25.0%), and KRAS mutations were detected in 9 cases(11.3%). NRAS mutations predominantly occurred at codons 12 and 13 of exon 2, as well as codon 61 of exon 3, while KRAS mutations were most commonly occurred at codons 12 and 13 of exon 2, all of which were missense mutations. There were no statistically significant differences observed in terms of age, sex, white blood cell count(WBC), hemoglobin(Hb), platelet count(PLT), bone marrow blasts, first induction chemotherapy regimen, CR1/CRi1 rates, chromosome karyotype, 2022 ELN risk classification and allogeneic hematopoietic stem cell transplantation(allo-HSCT) among the NRAS mutation group, KRAS mutation group and NRAS/KRAS wild-type group (P >0.05). KRAS mutations were significantly correlated with PTPN11 mutations (r =0.344), whereas no genes significantly associated with NRAS mutations were found. Survival analysis showed that compared to the NRAS/KRAS wild-type group, patients with NRAS mutation had a relatively higher 5-year overall survival (OS) rate and relapse-free survival (RFS) rate, though the differences were not statistically significant (P =0.097, P =0.249). Compared to the NRAS/KRAS wild-type group, patients with KRAS mutation had a lower 5-year OS rate and RFS rate, with no significant differences observed (P =0.275, P =0.442). There was no significant difference in the 5-year RFS rate between the KRAS mutation group and NRAS mutation group (P =0.157), but the 5-year OS rate of patients with KRAS mutation was significantly lower than that of patients with NRAS mutation (P =0.037).
CONCLUSION
In newly diagnosed AML patients, KRAS mutation was significantly correlated with PTPN11 mutation. Compared to patients with NRAS/KRAS wild-type, those with NRAS mutation showed a more favorable prognosis, while patients with KRAS mutation showed a poorer prognosis; however, these differences did not reach statistical significance. Notably, the prognosis of AML patients with KRAS mutation was significantly inferior compared to those with NRAS mutation.
Humans
;
Leukemia, Myeloid, Acute/diagnosis*
;
Mutation
;
Prognosis
;
Proto-Oncogene Proteins p21(ras)/genetics*
;
GTP Phosphohydrolases/genetics*
;
Retrospective Studies
;
Membrane Proteins/genetics*
;
Female
;
Male
;
Middle Aged
;
Adult
;
Aged
9.Noncoding RNA Terc-53 and hyaluronan receptor Hmmr regulate aging in mice.
Sipeng WU ; Yiqi CAI ; Lixiao ZHANG ; Xiang LI ; Xu LIU ; Guangkeng ZHOU ; Hongdi LUO ; Renjian LI ; Yujia HUO ; Zhirong ZHANG ; Siyi CHEN ; Jinliang HUANG ; Jiahao SHI ; Shanwei DING ; Zhe SUN ; Zizhuo ZHOU ; Pengcheng WANG ; Geng WANG
Protein & Cell 2025;16(1):28-48
One of the basic questions in the aging field is whether there is a fundamental difference between the aging of lower invertebrates and mammals. A major difference between the lower invertebrates and mammals is the abundancy of noncoding RNAs, most of which are not conserved. We have previously identified a noncoding RNA Terc-53 that is derived from the RNA component of telomerase Terc. To study its physiological functions, we generated two transgenic mouse models overexpressing the RNA in wild-type and early-aging Terc-/- backgrounds. Terc-53 mice showed age-related cognition decline and shortened life span, even though no developmental defects or physiological abnormality at an early age was observed, indicating its involvement in normal aging of mammals. Subsequent mechanistic study identified hyaluronan-mediated motility receptor (Hmmr) as the main effector of Terc-53. Terc-53 mediates the degradation of Hmmr, leading to an increase of inflammation in the affected tissues, accelerating organismal aging. adeno-associated virus delivered supplementation of Hmmr in the hippocampus reversed the cognition decline in Terc-53 transgenic mice. Neither Terc-53 nor Hmmr has homologs in C. elegans. Neither do arthropods express hyaluronan. These findings demonstrate the complexity of aging in mammals and open new paths for exploring noncoding RNA and Hmmr as means of treating age-related physical debilities and improving healthspan.
Animals
;
Mice
;
RNA, Untranslated/metabolism*
;
Aging/genetics*
;
Mice, Transgenic
;
Telomerase/metabolism*
;
RNA/genetics*
;
Hippocampus/metabolism*
;
Humans
;
Mice, Inbred C57BL
10.Engineering of CmpLs enhances L-glutamate production of Corynebacterium glutamicum.
Xingtao ZUO ; Shasha ZHONG ; Ningyun CAI ; Tuo SHI ; Zhidan ZHANG ; Yuantao LIU ; Jiao LIU ; Depei WANG ; Jiuzhou CHEN ; Ping ZHENG
Chinese Journal of Biotechnology 2025;41(1):271-287
The efficient production of L-glutamate is dependent on the product's rapid efflux, hence researchers have recently concentrated on artificially modifying its transport system and cell membrane wall structure. Considering the unique composition and structure of the cell wall of Corynebacterium glutamicum, we investigated the effects of CmpLs on L-glutamate synthesis and transport in SCgGC7, a constitutive L-glutamate efflux strain. First, the knockout strains of CmpLs were constructed, and it was confirmed that the deletion of CmpL1 and CmpL4 significantly improved the performance of L-glutamate producers. Next, temperature-sensitive L-glutamate fermentation with the CmpL1 and CmpL4 knockout strains were carried out in 5 L bioreactors, where the knockout strains showcased temperature-sensitive characteristics and enhanced capacities for L-glutamate production under high temperatures. Notably, the CmpL1 knockout strain outperformed the control strain in terms of L-glutamate production, showing production and yield increases of 69.2% and 55.3%, respectively. Finally, the intracellular and extracellular metabolites collected at the end of the fermentation process were analyzed. The modification of CmpLs greatly improved the L-glutamate excretion and metabolic flux for both L-glutamate production and transport. Additionally, the CmpL1 knockout strain showed decreased accumulation of downstream metabolites of L-glutamate and intermediate metabolites of tricarboxylic acid (TCA) cycle, which were consistent with its high L-glutamate biosynthesis capacity. In addition to offering an ideal target for improving the stability and performance of the industrial strains for L-glutamate production, the functional complementarity and redundancy of CmpLs provide a novel target and method for improving the transport of other metabolites by modification of the cell membrane and cell wall structures in C. glutamicum.
Corynebacterium glutamicum/genetics*
;
Glutamic Acid/biosynthesis*
;
Fermentation
;
Metabolic Engineering
;
Bacterial Proteins/metabolism*
;
Bioreactors/microbiology*
;
Gene Knockout Techniques


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