1.Study on mechanism of naringin in alleviating cerebral ischemia/reperfusion injury based on DRP1/LRRK2/MCU axis.
Kai-Mei TAN ; Hong-Yu ZENG ; Feng QIU ; Yun XIANG ; Zi-Yang ZHOU ; Da-Hua WU ; Chang LEI ; Hong-Qing ZHAO ; Yu-Hong WANG ; Xiu-Li ZHANG
China Journal of Chinese Materia Medica 2025;50(9):2484-2494
This study aims to investigate the molecular mechanism by which naringin alleviates cerebral ischemia/reperfusion(CI/R) injury through DRP1/LRRK2/MCU signaling axis. A total of 60 SD rats were randomly divided into the sham group, the model group, the sodium Danshensu group, and low-, medium-, and high-dose(50, 100, and 200 mg·kg~(-1)) naringin groups, with 10 rats in each group. Except for the sham group, a transient middle cerebral artery occlusion/reperfusion(tMCAO/R) model was established in SD rats using the suture method. Longa 5-point scale was used to assess neurological deficits. 2,3,5-Triphenyl tetrazolium chloride(TTC) staining was used to detect the volume percentage of cerebral infarction in rats. Hematoxylin-eosin(HE) staining and Nissl staining were employed to assess neuronal structural alterations and the number of Nissl bodies in cortex, respectively. Western blot was used to determine the protein expression levels of B-cell lymphoma-2 gene(Bcl-2), Bcl-2-associated X protein(Bax), cleaved cysteine-aspartate protease-3(cleaved caspase-3), mitochondrial calcium uniporter(MCU), microtubule-associated protein 1 light chain 3(LC3), and P62. Mitochondrial structure and autophagy in cortical neurons were observed by transmission electron microscopy. Immunofluorescence assay was used to quantify the fluorescence intensities of MCU and mitochondrial calcium ion, as well as the co-localization of dynamin-related protein 1(DRP1) with leucine-rich repeat kinase 2(LRRK2) and translocase of outer mitochondrial membrane 20(TOMM20) with LC3 in cortical mitochondria. The results showed that compared with the model group, naringin significantly decreased the volume percentage of cerebral infarction and neurological deficit score in tMCAO/R rats, alleviated the structural damage and Nissl body loss of cortical neurons in tMCAO/R rats, inhibited autophagosomes in cortical neurons, and increased the average diameter of cortical mitochondria. The Western blot results showed that compared to the sham group, the model group exhibited increased levels of cleaved caspase-3, Bax, MCU, and the LC3Ⅱ/LC3Ⅰ ratio in the cortex and reduced protein levels of Bcl-2 and P62. However, naringin down-regulated the protein expression of cleaved caspase-3, Bax, MCU and the ratio of LC3Ⅱ/LC3Ⅰ ratio and up-regulated the expression of Bcl-2 and P62 proteins in cortical area. In addition, immunofluorescence analysis showed that compared with the model group, naringin and positive drug treatments significantly decreased the fluorescence intensities of MCU and mitochondrial calcium ion. Meanwhile, the co-localization of DRP1 with LRRK2 and TOMM20 with LC3 in cortical mitochondria was also decreased significantly after the intervention. These findings suggest that naringin can alleviate cortical neuronal damage in tMCAO/R rats by inhibiting DRP1/LRRK2/MCU-mediated mitochondrial fragmentation and the resultant excessive mitophagy.
Animals
;
Rats, Sprague-Dawley
;
Reperfusion Injury/genetics*
;
Flavanones/administration & dosage*
;
Rats
;
Dynamins/genetics*
;
Male
;
Brain Ischemia/genetics*
;
Protein Serine-Threonine Kinases/genetics*
;
Signal Transduction/drug effects*
;
Humans
;
Drugs, Chinese Herbal/administration & dosage*
2.Mechanism of vanillic acid against cardiac fibrosis induced by isoproterenol in mice based on Drp1/HK1/NLRP3 and mitochondrial apoptosis signaling pathways.
Hai-Bo HE ; Mian WU ; Jie XU ; Qian-Qian XU ; Fang-Zhu WAN ; Hua-Qiao ZHONG ; Ji-Hong ZHANG ; Gang ZHOU ; Hui-Lin QIN ; Hao-Ran LI ; Hai-Ming TANG
China Journal of Chinese Materia Medica 2025;50(8):2193-2208
This study investigated the effects and underlying mechanisms of vanillic acid(VA) against cardiac fibrosis(CF) induced by isoproterenol(ISO) in mice. Male C57BL/6J mice were randomly divided into control group, VA group(100 mg·kg~(-1), ig), ISO group(10 mg·kg~(-1), sc), ISO + VA group(10 mg·kg~(-1), sc + 100 mg·kg~(-1), ig), ISO + dynamin-related protein 1(Drp1) inhibitor(Mdivi-1) group(10 mg·kg~(-1), sc + 50 mg·kg~(-1), ip), and ISO + VA + Mdivi-1 group(10 mg·kg~(-1), sc + 100 mg·kg~(-1), ig + 50 mg·kg~(-1), ip). The treatment groups received the corresponding medications once daily for 14 consecutive days. On the day after the last administration, cardiac functions were evaluated, and serum and cardiac tissue samples were collected. These samples were analyzed for serum aspartate aminotransferase(AST), lactate dehydrogenase(LDH), creatine kinase-MB(CK-MB), cardiac troponin I(cTnI), reactive oxygen species(ROS), interleukin(IL)-1β, IL-4, IL-6, IL-10, IL-18, and tumor necrosis factor-α(TNF-α) levels, as well as cardiac tissue catalase(CAT), glutathione(GSH), malondialdehyde(MDA), myeloperoxidase(MPO), superoxide dismutase(SOD), total antioxidant capacity(T-AOC) activities, and cytochrome C levels in mitochondria and cytoplasm. Hematoxylin-eosin, Masson, uranium acetate and lead citrate staining were used to observe morphological and mitochondrial ultrastructural changes in the cardiac tissues, and myocardial injury area and collagen volume fraction were calculated. Flow cytometry was applied to detect the relative content and M1/M2 polarization of cardiac macrophages. The mRNA expression levels of macrophage polarization markers [CD86, CD206, arginase 1(Arg-1), inducible nitric oxide synthase(iNOS)], CF markers [type Ⅰ collagen(Coll Ⅰ), Coll Ⅲ, α-smooth muscle actin(α-SMA)], and cytokines(IL-1β, IL-4, IL-6, IL-10, IL-18, TNF-α) in cardiac tissues were determined by quantitative real-time PCR. Western blot was used to detect the protein expression levels of Coll Ⅰ, Coll Ⅲ, α-SMA, Drp1, p-Drp1, voltage-dependent anion channel(VDAC), hexokinase 1(HK1), NOD-like receptor protein 3(NLRP3), apoptosis-associated speck-like protein(ASC), caspase-1, cleaved-caspase-1, gasdermin D(GSDMD), cleaved N-terminal gasdermin D(GSDMD-N), IL-1β, IL-18, B-cell lymphoma-2(Bcl-2), B-cell lymphoma-xl(Bcl-xl), Bcl-2-associated death promoter(Bad), Bcl-2-associated X protein(Bax), apoptotic protease activating factor-1(Apaf-1), pro-caspase-3, cleaved-caspase-3, pro-caspase-9, cleaved-caspase-9, poly(ADP-ribose) polymerase-1(PARP-1), and cleaved-PARP-1 in cardiac tissues. The results showed that VA significantly improved cardiac function in mice with CF, reduced myocardial injury area and cardiac index, and decreased serum levels of AST, CK-MB, cTnI, LDH, ROS, IL-1β, IL-6, IL-18, and TNF-α. VA also lowered MDA and MPO levels, mRNA expressions of IL-1β, IL-6, IL-18, and TNF-α, and mRNA and protein expressions of Coll Ⅰ, Coll Ⅲ, and α-SMA in cardiac tissues, and increased serum levels of IL-4 and IL-10, cardiac tissue levels of CAT, GSH, SOD, and T-AOC, and mRNA expressions of IL-4 and IL-10. Additionally, VA ameliorated cardiac pathological damage, inhibited myocardial cell apoptosis, inflammatory infiltration, and collagen fiber deposition, reduced collagen volume fraction, and alleviated mitochondrial damage. VA decreased the ratio of F4/80~+CD86~+ M1 cells and the mRNA expressions of CD86 and iNOS in cardiac tissue, and increased the ratio of F4/80~+CD206~+ M2 cells and the mRNA expressions of CD206 and Arg-1. VA also reduced protein expressions of p-Drp1, VDAC, NLRP3, ASC, caspase-1, cleaved-caspase-1, GSDMD, GSDMD-N, IL-1β, IL-18, Bad, Bax, Apaf-1, cleaved-caspase-3, cleaved-caspase-9, cleaved-PARP-1, and cytoplasmic cytochrome C, and increased the expressions of HK1, Bcl-2, Bcl-xl, pro-caspase-3, pro-caspase-9 proteins, as well as the Bcl-2/Bax and Bcl-xl/Bad ratios and mitochondrial cytochrome C content. These results indicate that VA has a significant ameliorative effect on ISO-induced CF in mice, alleviates ISO-induced oxidative damage and inflammatory response, and its mechanism may be closely related to the inhibition of Drp1/HK1/NLRP3 and mitochondrial apoptosis signaling pathways, suppression of myocardial cell inflammatory infiltration and collagen fiber deposition, reduction of collagen volume fraction and CollⅠ, Coll Ⅲ, and α-SMA expressions, thus mitigating CF.
Animals
;
Isoproterenol/adverse effects*
;
Male
;
Mice
;
Signal Transduction/drug effects*
;
Vanillic Acid/administration & dosage*
;
Dynamins/genetics*
;
Mice, Inbred C57BL
;
Fibrosis/genetics*
;
Apoptosis/drug effects*
;
Mitochondria/metabolism*
;
NLR Family, Pyrin Domain-Containing 3 Protein/genetics*
;
Myocardium/metabolism*
;
Humans
3.Mechanism of Sorbus tianschanica in regulating asthmatic airway inflammation through TLR4/PI3K/Akt/MMP9 signaling pathway.
Wen-Kai WANG ; Jun-Min CHANG ; Xiao-Li MA ; Gai-Ru LI
China Journal of Chinese Materia Medica 2025;50(15):4304-4314
To investigate the effects and mechanisms of the water extract from Sorbus tianschanica(STE) on asthmatic airway inflammation, the mice were randomly divided into six groups, including a control group, a model group, a positive drug dexamethasone group(2 mg·kg~(-1)), a low-dose STE group(1 g·kg~(-1)), a medium-dose STE group(2 g·kg~(-1)), and a high-dose STE group(4 g·kg~(-1)). Except for the control group, all groups were subjected to ovalbumin induction to establish an asthma mouse model. The anti-inflammatory effects of STE were evaluated by examining pathological changes in lung tissue and measuring the levels of interleukin(IL)-4 and IL-5 in bronchoalveolar lavage fluid(BALF). Transcriptomic and proteomic methods were further employed to analyze differentially expressed genes and proteins, as well as their associated signaling pathways in lung tissue. Subsequently, the expression changes of key genes were verified by reverse transcription-quantitative polymerase chain reaction(RT-qPCR), and immunohistochemistry and Western blot methods were used to explore the regulatory mechanisms of STE in the pathogenesis of asthma in mice. Molecular docking was performed by using AutoDock Vina software to evaluate the binding affinity of the main active components in STE with the target proteins, including phosphatidylinositol-3-kinase catalytic subunit α(PIK3CA), Toll-like receptor 4(TLR4), protein kinase B1(Akt1), and matrix metallopeptidase 9(MMP9). The results showed significant inflammatory cell infiltration and fibrous tissue proliferation in the lung tissue of mice in the model group. However, these pathological changes were markedly reduced following STE intervention. Compared with those of the control group, the expression levels of IL-4 and IL-5 in the BALF of the model group were significantly increased but notably decreased following STE intervention. Transcriptomic and proteomic analyses identified key genes and proteins associated with allergic asthma, including tumor necrosis factor(TNF), IL-6, TLR4, PIK3CA, and MMP9. RT-qPCR validation revealed that high-dose STE intervention significantly downregulated the expressions of PIK3CA, IL-6, Akt1, MMP9, IL-13, nuclear factor-kappa B(NF-κB), TNF, CXC motif chemokine ligand 1(CXCL1), and TLR4 mRNAs and significantly upregulated the expression of signal transducer and activator of transcription 1(STAT1) mRNA. Western blot and immunohistochemical analyses confirmed that STE significantly downregulated the expressions of MMP9, TLR4, PIK3CA, and phosphorylated protein kinase B(p-Akt) in lung tissue of asthmatic mice. Moreover, molecular docking demonstrated that kaempferol-3,7-diglucoside, isoquercitrin, quercetin-3-gentiobioside, and hyperoside in STE exhibited stable binding affinities with PIK3CA, TLR4, Akt1, and MMP9, suggesting that the active components may exert anti-inflammatory effects by targeting and modulating asthma-related signaling pathways. In summary, STE exerts anti-asthmatic effects by inhibiting the expressions of PIK3CA, MMP9, p-Akt, and TLR4 and regulating the TLR4/PI3K/Akt/MMP9 signaling pathway.
Animals
;
Asthma/metabolism*
;
Toll-Like Receptor 4/metabolism*
;
Signal Transduction/drug effects*
;
Mice
;
Phosphatidylinositol 3-Kinases/metabolism*
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Matrix Metalloproteinase 9/metabolism*
;
Mice, Inbred BALB C
;
Drugs, Chinese Herbal/administration & dosage*
;
Female
;
Humans
;
Lung/immunology*
;
Male
4.Pseudogene Lamr1-ps1 Aggravates Early Spatial Learning Memory Deficits in Alzheimer's Disease Model Mice.
Zhuoze WU ; Xiaojie LIU ; Yuntai WANG ; Zimeng ZENG ; Wei CHEN ; Hao LI
Neuroscience Bulletin 2025;41(4):600-614
Alzheimer's disease (AD), a neurodegenerative disorder with complex etiologies, manifests through a cascade of pathological changes before clinical symptoms become apparent. Among these early changes, alterations in the expression of non-coding RNAs (ncRNAs) have emerged as pivotal events. In this study, we focused on the aberrant expression of ncRNAs and revealed that Lamr1-ps1, a pseudogene of the laminin receptor, significantly exacerbates early spatial learning and memory deficits in APP/PS1 mice. Through a combination of bioinformatics prediction and experimental validation, we identified the miR-29c/Bace1 pathway as a potential regulatory mechanism by which Lamr1-ps1 influences AD pathology. Importantly, augmenting the miR-29c-3p levels in mice ameliorated memory deficits, underscoring the therapeutic potential of targeting miR-29c-3p in early AD intervention. This study not only provides new insights into the role of pseudogenes in AD but also consolidates a foundational basis for considering miR-29c as a viable therapeutic target, offering a novel avenue for AD research and treatment strategies.
Animals
;
Alzheimer Disease/pathology*
;
Pseudogenes/genetics*
;
Mice
;
Memory Disorders/metabolism*
;
MicroRNAs/genetics*
;
Disease Models, Animal
;
Spatial Learning/physiology*
;
Mice, Transgenic
;
Presenilin-1/genetics*
;
Male
;
Amyloid Precursor Protein Secretases/metabolism*
;
Mice, Inbred C57BL
;
Aspartic Acid Endopeptidases/metabolism*
5.GALM Alleviates Aβ Pathology and Cognitive Deficit Through Increasing ADAM10 Maturation in a Mouse Model of Alzheimer's Disease.
Na TIAN ; Junjie LI ; Xiuyu SHI ; Mingliang XU ; Qian XIAO ; Qiuyun TIAN ; Mulan CHEN ; Weihong SONG ; Yehong DU ; Zhifang DONG
Neuroscience Bulletin 2025;41(8):1377-1389
Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder worldwide, causing dementia and affecting millions of individuals. One prominent characteristic in the brains of AD patients is glucose hypometabolism. In the context of galactose metabolism, intracellular glucose levels are heightened. Galactose mutarotase (GALM) plays a crucial role in maintaining normal galactose metabolism by catalyzing the conversion of β-D-galactose into α-D-galactose (α-D-G). The latter is then converted into glucose-6-phosphate, improving glucose metabolism levels. However, the involvement of GALM in AD progression is still unclear. In the present study, we found that the expression of GALM was significantly increased in AD patients and model mice. Genetic knockdown of GALM using adeno-associated virus did not change the expression of amyloid precursor protein (APP) and APP-cleaving enzymes including a disintegrin and metalloprotease 10 (ADAM10), β-site APP-cleaving enzyme 1 (BACE1), and presenilin-1 (PS1). Interestingly, genetic overexpression of GALM reduced APP and Aβ deposition by increasing the maturation of ADAM10, although it did not alter the expression of BACE1 and PS1. Further electrophysiological and behavioral experiments showed that GALM overexpression significantly ameliorated the deficits in hippocampal CA1 long-term potentiation (LTP) and spatial learning and memory in AD model mice. Importantly, direct α-D-G (20 mg/kg, i.p.) also inhibited Aβ deposition by increasing the maturation of ADAM10, thereby improving hippocampal CA1 LTP and spatial learning and memory in AD model mice. Taken together, our results indicate that GALM shifts APP processing towards α-cleavage, preventing Aβ generation by increasing the level of mature ADAM10. These findings indicate that GALM may be a potential therapeutic target for AD, and α-D-G has the potential to be used as a dietary supplement for the prevention and treatment of AD.
Animals
;
ADAM10 Protein/metabolism*
;
Alzheimer Disease/pathology*
;
Amyloid Precursor Protein Secretases/metabolism*
;
Disease Models, Animal
;
Humans
;
Mice
;
Amyloid beta-Peptides/metabolism*
;
Male
;
Mice, Transgenic
;
Membrane Proteins/metabolism*
;
Cognitive Dysfunction/pathology*
;
Mice, Inbred C57BL
;
Amyloid beta-Protein Precursor/metabolism*
;
Female
;
Hippocampus/metabolism*
;
Long-Term Potentiation/physiology*
6.Salvianolic Acid B and Ginsenoside Rg1 Combination Attenuates Cerebral Edema Accompanying Glymphatic Modulation.
Lingxiao ZHANG ; Yanan SHAO ; Zhao FANG ; Siqi CHEN ; Yixuan WANG ; Han SHA ; Yuhan ZHANG ; Linlin WANG ; Yi JIN ; Hao CHEN ; Baohong JIANG
Neuroscience Bulletin 2025;41(11):1909-1923
Cerebral edema is characterized by fluid accumulation, and the glymphatic system (GS) plays a pivotal role in regulating fluid transport. Using the Tenecteplase system, magnesium salt of salvianolic acid B/ginsenoside Rg1 (SalB/Rg1) was injected intravenously into mice 4.5 h after middle cerebral artery occlusion and once every 24 h for the following 72 h. GS function was assessed by Evans blue imaging, near-infrared fluorescence region II (NIR-II) imaging, and magnetic resonance imaging (MRI). SalB/Rg1 had significant effects on reducing the infarct volume and hemorrhagic transformation score, improving neurobehavioral function, and protecting tissue structure, especially inhibiting cerebral edema. Meanwhile, the influx/efflux drainage of GS was enhanced by SalB/Rg1 according to NIR-II imaging and MRI. SalB/Rg1 inhibited matrix metalloproteinase-9 (MMP-9) activity, reduced cleaved β-dystroglycan (β-DG), and stabilized aquaporin-4 (AQP4) polarity, which was verified by colocalization with CD31. Our findings indicated that SalB/Rg1 treatment enhances GS function and attenuates cerebral edema, accompanying the regulation of the MMP9/β-DG/AQP4 pathway.
Animals
;
Ginsenosides/administration & dosage*
;
Brain Edema/etiology*
;
Male
;
Benzofurans/administration & dosage*
;
Glymphatic System/diagnostic imaging*
;
Mice
;
Infarction, Middle Cerebral Artery/drug therapy*
;
Aquaporin 4/metabolism*
;
Disease Models, Animal
;
Mice, Inbred C57BL
;
Matrix Metalloproteinase 9/metabolism*
;
Neuroprotective Agents/pharmacology*
;
Depsides
7.Research progress on the relationship between mitochondrial dynamics imbalance and novel coronavirus infection-related acute respiratory distress syndrome.
Zijia ZHANG ; Bin DU ; Xunyao WU ; Xiaoyun HU ; Shitong DIAO ; Run DONG
Chinese Critical Care Medicine 2025;37(3):300-304
Patients with severe pneumonia caused by novel coronavirus infection are often complicated with acute respiratory distress syndrome (ARDS), which has a high mortality. ARDS is characterized by diffuse alveolar damage, pulmonary edema, and hypoxemia. Mitochondria are prone to morphological and functional abnormalities under hypoxia and viral infection, which can lead to cell apoptosis and damage, severely impacting the disease progression. Mitochondria maintain homeostasis through fission and fusion. In ARDS, hypoxia leads to the phosphorylation of dynamin-related protein 1 (Drp1), triggering excessive mitochondrial fission and damaging the alveolar epithelial barrier. Animal experiments have shown that inhibiting this process can alleviate lung injury, providing a potential direction for treatment. The pathology of novel coronavirus infection-related ARDS is similar to that of typical ARDS but more severe. Viral infection and hypoxia disrupt the mitochondrial balance, causing fission and autophagy abnormalities, promoting oxidative stress and mitochondrial DNA (mtDNA) release, activating inflammasomes, inducing the expression of hypoxia-inducible factor-1α (HIF-1α), exacerbating viral infection, inflammation, and coagulation reactions, and resulting in multiple organ damage. Mechanical ventilation and glucocorticoids are commonly used in the treatment of novel coronavirus infection-related ARDS. Mechanical ventilation is likely to cause lung and diaphragm injuries and changes in mitochondrial dynamics, while the lung protective ventilation strategy can reduce the adverse effects. Glucocorticoids can regulate mitochondrial function and immune response and improve the patient's condition through multiple pathways. The mitochondrial dynamics imbalance in novel coronavirus infection-related ARDS is caused by hypoxia and viral proteins, leading to lung and multiple organ injuries. To clarify the pathophysiological mechanism of mitochondrial dynamics imbalance in novel coronavirus infection-related ARDS and explore effective strategies for regulating mitochondrial dynamics balance to treat this disease, so as to provide new treatment targets and methods for patients with novel coronavirus infection-related ARDS. The existing treatments have limitations. Future research needs to deeply study the mechanism of mitochondrial dysfunction, develop new therapies and regulatory strategies, and improve the treatment effect.
Humans
;
Respiratory Distress Syndrome/etiology*
;
COVID-19
;
Mitochondrial Dynamics
;
Mitochondria/metabolism*
;
DNA, Mitochondrial
;
Hypoxia-Inducible Factor 1, alpha Subunit/metabolism*
;
Dynamins
;
SARS-CoV-2
8.Expression and enzymatic characterization of a chitosanase with tolerance to a wide range of pH from <i>Bacillus atrophaeusi>.
Wenjuan DU ; Awagul TURSUN ; Zhiqin DONG ; Huijuan MA ; Zhenghai MA
Chinese Journal of Biotechnology 2025;41(1):352-362
To screen and identify a chitosanase with high stability, we cloned the chitosanase gene from <i>Bacillus atrophaeusi> with a high protease yield from the barren saline-alkali soil and expressed this gene in <i>Escherichia colii>. The expressed chitosanase of <i>Bi>. <i>atrophaeusi> (BA-CSN) was purified by nickel-affinity column chromatography. The properties including optimal temperature, optimal pH, substrate specificity, and kinetic parameters of BA-CSN were characterized. The results showed that BA-CSN had the molecular weight of 31.13 kDa, the optimal temperature of 55 ℃, the optimal pH 5.5, and good stability at temperatures below 45 ℃ and pH 4.0-9.0. BA-CSN also had good stability within 4 h of pH 3.0 and 10.0, be activated by K+, Na+, Mn2+, Ca2+, Mg2+, and Co2+, (especially by Mn2+), and be inhibited by Fe3+, Cu2+, and Ag+. BA-CSN showcased the highest relative activity in the hydrolysis of colloidal chitosan, and it had good hydrolysis ability for colloidal chitin. Under the optimal catalytic conditions, BA-CSN demonstrated the Michaelis constant <i>Ki>m and maximum reaction rate <i>Vi>max of 9.94 mg/mL and 26.624 μmoL/(mL·min), respectively, for colloidal chitosan. In short, BA-CSN has strong tolerance to acids and alkali, possessing broad industrial application prospects.
Bacillus/genetics*
;
Hydrogen-Ion Concentration
;
Escherichia coli/metabolism*
;
Glycoside Hydrolases/biosynthesis*
;
Substrate Specificity
;
Enzyme Stability
;
Chitosan/metabolism*
;
Temperature
;
Kinetics
;
Cloning, Molecular
;
Bacterial Proteins/biosynthesis*
;
Recombinant Proteins/genetics*
9.Discovery and protein engineering of penicillin G acylase for biosynthesis of cefradine.
Lingyi LIU ; Xiangying LI ; Congcong LI ; Lijuan MA ; Bo YUAN ; Zhoutong SUN
Chinese Journal of Biotechnology 2025;41(9):3630-3642
Penicillin G acylases (PGAs) are industrially important enzymes primarily used for the synthesis of first- and second-generation cephalosporins or penicillins. This study aims to establish a high-efficiency biosynthetic system for cefradine on the purpose of significantly enhancing its catalytic efficiency in cefradine synthesis and developing its potentials for industrial application. In this study, we identified and engineered penicillin G acylase and obtained a highly active mutant <i>Ksi>PGA M7(M168F/F313G) for the synthesis of cefradine. The mutant achieved a conversion rate over 95% in the scaled-up reaction. To validate its industrial applicability, we immobilized both the wild-type and mutant enzymes and applied them in continuous flow reactions, which achieved a space-time yield of 2 800 g/(L·d). This study lays a foundation for the future applications of penicillin G acylases in the industrial synthesis of cefradine.
Penicillin Amidase/biosynthesis*
;
Protein Engineering/methods*
;
Cephradine/metabolism*
;
Escherichia coli/metabolism*
;
Enzymes, Immobilized/metabolism*
;
Recombinant Proteins/biosynthesis*
10.Characteristics of immune response induced by mucosal immunization with recombinant adenovirus of Mycobacterium tuberculosis phosphodiesterase.
Ting DAI ; Yanzhi LU ; Ruihua ZHAO ; Huanhuan NING ; Jian KANG ; Leran HAO ; Jialing LI ; Yuxiao CHANG ; Yinlan BAI
Chinese Journal of Cellular and Molecular Immunology 2025;41(1):1-8
Objective The prevalence of drug-resistant Mycobacterium tuberculosis (Mtb) strains is exacerbating the global burden of tuberculosis (TB), highlighting the urgent need for new treatment strategies for TB. Methods The recombinant adenovirus vaccine expressing cyclic di-adenosine monophosphate (c-di-AMP) phosphodiesterase B (CnpB) (rAd-CnpB), was administered to normal mice via mucosal immunization, either alone or in combination with drug therapy, to treat Mtb respiratory infections in mice.Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of antibodies in serum and bronchoalveolar lavage fluid (BALF). Real-time quantitative PCR was performed to assess the transcription levels of cytokines interferon γ(IFN-γ) and interleukin 10(IL-10) in mouse lungs. Flow cytometry was used to determine the proportions of CD4+ and CD8+ T cell subsets in the lungs and spleens. ELISA was employed to measure the levels of cytokines IFN-γ, IL-2, IL-10, inflammatory factors IL-6, and tumor necrosis factor α (TNF-α) secreted by spleen cells following antigen stimulation. The bacteria loads in the lungs and spleens of Mtb-infected mice were enumerated by plate counting methods. Resluts Intranasal immunization with rAd-CnpB induced high titers of IgG in mouse serum and the production of IgG and IgA in BALF, along with alterations in T lymphocyte subsets in the lungs and spleens. Administration of rAd-CnpB, either alone or in combination with drugs, to Mtb-infected mice significantly increased serum IgG levels as well as IgA and IgG levels in BALF. rAd-CnpB immunization promoted the secretion of CnpB-specific cytokines and inflammatory factors by splenocytes in Mtb-infected mice. However, rAd-CnpB immunotherapy, either alone or combined with drugs, did not significantly affect the bacterial loads in the lungs and spleens of mice with Mtb respiratory infections. Conclusion Mucosal immunization with rAd-CnpB induced significant mucosal, humoral and cellular immune responses in mice, and significantly enhanced CnpB-specific cellular immune responses in Mtb-infected mice.
Animals
;
Adenoviridae/immunology*
;
Mycobacterium tuberculosis/genetics*
;
Mice
;
Female
;
Phosphoric Diester Hydrolases/genetics*
;
Tuberculosis Vaccines/administration & dosage*
;
Tuberculosis/prevention & control*
;
Mice, Inbred BALB C
;
Cytokines
;
Lung/microbiology*
;
Immunization
;
Bronchoalveolar Lavage Fluid/immunology*
;
Immunity, Mucosal

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