Objective To determine the effects of hypoxia pre-treatment combined with radiation damage on the hematopoietic cells in the bone marrow of mice.Methods A total of 165 male C57BL/6 mice(10～12 weeks old,weighing 20～25 g)were randomly divided into 7 groups:normal control(Control,n=33),6 Gy irradiation(6-Gy,n=43),7 d hypoxia-6 Gy irradiation(Hy-7 d+6 Gy,n=43),7 Gy irradiation(7 Gy,n=12),7 d hypoxia-7 Gy irradiation(Hy-7 d+7 Gy,n=12),7 Gy continuous hypoxia treatment(Hy-7 d+7 Gy+Hy,n=12),and 6 Gy continuous hypoxia treatment(Hy-7 d+6 Gy+Hy,n=10).The mice of the hypoxia treatment groups were given 7-day hypoxic pretreatment(12%oxygen)in a normobaric hypoxic chamber,while those of the other groups were housed in normoxic condition.After pretreatment,the mice of the irradiation groups were exposed to a single 6 or 7 Gy of whole-body 60Co γ-irradiation in normoxia.The mice of the hypoxia and irradiation groups were kept in hypoxic condition in 24 h post-irradiation followed by being resumed to normoxia,while those of the continuous hypoxia treatment groups were remained in hypoxia.After bone marrow cell suspensions were prepared from the Control,6 Gy,and Hy-7 d+6 Gy groups,bone marrow nucleated cells(BMNCs)were counted via automated cell counter.HE staining was employed to observe pathologic changes in medullary cavity,and flow cytometry was used to assess Lin-Sca1?c-Kit?(LSK)hematopoietic stem/progenitor cells,myeloid progenitors(MPs),and mature T/B/myeloid cells.The mice of the 7 Gy,Hy-7 d+7 Gy,and Hy-7 d+7 Gy+Hy groups were monitored for 30-day survival after hypoxic pretreatment.The dynamic changes in the counts of red blood cells(RBC),white blood cells(WBC)and platelets(PLT),and hemoglobin(HGB)level were observed in the 6 Gy,Hy-7 d+6 Gy,and Hy-7 d+6 Gy+Hy groups with aid of a fully automatic blood analyzer.Single-cell RNA sequencing was performed on bone marrow cell suspension derived from the mice euthanized in 17 d after irradiation from the Control,6 Gy,and Hy-7 d+6 Gy groups.Results ①Compared to the Control group,the 6 Gy group showed significantly reduced BMNCs(P<0.01),dilated bone marrow sinusoids,and erythrocyte extravasation.The Hy-7 d+6 Gy group exhibited higher cellular density and attenuated BMNC loss than the 6 Gy group(P<0.01).②Flow cytometry revealed less LSK,MP,and mature T/B/myeloid cells in the 6 Gy group than the Control group(P<0.05),and the reduced counts of LSK and MP were mitigated in the Hy-7 d+6 Gy group(P<0.01).③The Hy-7 d+7 Gy group demonstrated improved 30-day survival than the 7 Gy group(P<0.01),while continuous hypoxia(Hy-7 d+7 Gy+Hy)failed to enhance the survival.No statistical difference was seen in the survival rate between the 2 groups(P=0.12),though the Hy-7 d+7 Gy group showing higher survival rate.④Routine blood test revealed that the Hy-7 d+6 Gy group showed faster WBC recovery(vs the 6 Gy and Hy-7 d+6 Gy+Hy groups,P<0.05),higher pre-irradiation RBC/HGB levels,and accelerated PLT restoration(P<0.05).⑤Single-cell RNA sequencing indicated that hypoxia pretreatment suppressed the numbers of long-term hematopoietic stem cells/short-term hematopoietic stem cells(LT-HSC/ST-HSC)depletion in the Hy-7 d+6 Gy group when compared with the 6 Gy group,which was consistent with the results of flow cytometry.Pseudotime trajectory aligned the Hy-7 d+6 Gy group,as the Control group,showed enriched undifferentiated LSKs.Differential gene analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis revealed that oxidative phosphorylation pathway was strongly activated in the 6 Gy group,while the Hy-7 d+6 Gy group had enriched in chromatin remodeling and mRNA surveillance pathways.Conclusion Hypoxic preconditioning alleviates radiation-induced bone marrow injury,and post-irradiation normoxia restoration promotes hematopoietic recovery in acute radiation-exposed mice.

Background: Medicinal plants rich in endophytic fungi are a significant source of natural lead compounds. Meroterpenoids, which are hybrid natural products originating from partially terpenoid pathways, exhibit impressive structural complexity and substantial potential as drug candidates. The structural diversity of meroterpenoids is largely attributed to the functional diversity of terpenoid cyclases, which generate a variety of terpenoid compounds with different ring systems. This enzymatic versatility underscores the biochemical potential of endophytic fungi and their invaluable role in drug discovery. Objective: The aim of the study was to investigate the role of endophytic fungi from Paris polyphylla var. yunnanensis in facilitating diverse cyclization modifications of meroditerpenoids through four terpene cyclases (TCs) from the Pyr4 family. Methods: This study utilized a recombinant strategy to successfully reconstruct four distinct TCs from endophytic fungi in the heterologous host, Aspergillus oryzae NSAR1. The structural characterization of the resulting secondary metabolites was performed using mass spectrometry and NMR techniques. Results: The substitution of TCs from the endophytes Aspergillus felis 0260 and Fusarium graminearum 1962 in Aspergillus oryzae through hydrophobic intermediates 1 and 2, led to the production of meroditerpenoids sartorypyrone C (3) and a new compound, 4′-methylchevalone E (4), respectively. This study demonstrates the critical role of endophytic fungi in enhancing structural diversity. Conclusions: These findings provide valuable insights into the compatibility of pathway combinations and the interchangeability of terpene cyclases derived from endophytic fungi in medicinal plants, which advanced the understanding of meroditerpenoid biosynthesis and highlighted the importance of endophytic fungi in drug discovery.

Background: Medicinal plants rich in endophytic fungi are a significant source of natural lead compounds. Meroterpenoids, which are hybrid natural products originating from partially terpenoid pathways, exhibit impressive structural complexity and substantial potential as drug candidates. The structural diversity of meroterpenoids is largely attributed to the functional diversity of terpenoid cyclases, which generate a variety of terpenoid compounds with different ring systems. This enzymatic versatility underscores the biochemical potential of endophytic fungi and their invaluable role in drug discovery. Objective: The aim of the study was to investigate the role of endophytic fungi from Paris polyphylla var. yunnanensis in facilitating diverse cyclization modifications of meroditerpenoids through four terpene cyclases (TCs) from the Pyr4 family. Methods: This study utilized a recombinant strategy to successfully reconstruct four distinct TCs from endophytic fungi in the heterologous host, Aspergillus oryzae NSAR1. The structural characterization of the resulting secondary metabolites was performed using mass spectrometry and NMR techniques. Results: The substitution of TCs from the endophytes Aspergillus felis 0260 and Fusarium graminearum 1962 in Aspergillus oryzae through hydrophobic intermediates 1 and 2, led to the production of meroditerpenoids sartorypyrone C (3) and a new compound, 4′-methylchevalone E (4), respectively. This study demonstrates the critical role of endophytic fungi in enhancing structural diversity. Conclusions: These findings provide valuable insights into the compatibility of pathway combinations and the interchangeability of terpene cyclases derived from endophytic fungi in medicinal plants, which advanced the understanding of meroditerpenoid biosynthesis and highlighted the importance of endophytic fungi in drug discovery.

Background: Medicinal plants rich in endophytic fungi are a significant source of natural lead compounds. Meroterpenoids, which are hybrid natural products originating from partially terpenoid pathways, exhibit impressive structural complexity and substantial potential as drug candidates. The structural diversity of meroterpenoids is largely attributed to the functional diversity of terpenoid cyclases, which generate a variety of terpenoid compounds with different ring systems. This enzymatic versatility underscores the biochemical potential of endophytic fungi and their invaluable role in drug discovery. Objective: The aim of the study was to investigate the role of endophytic fungi from Paris polyphylla var. yunnanensis in facilitating diverse cyclization modifications of meroditerpenoids through four terpene cyclases (TCs) from the Pyr4 family. Methods: This study utilized a recombinant strategy to successfully reconstruct four distinct TCs from endophytic fungi in the heterologous host, Aspergillus oryzae NSAR1. The structural characterization of the resulting secondary metabolites was performed using mass spectrometry and NMR techniques. Results: The substitution of TCs from the endophytes Aspergillus felis 0260 and Fusarium graminearum 1962 in Aspergillus oryzae through hydrophobic intermediates 1 and 2, led to the production of meroditerpenoids sartorypyrone C (3) and a new compound, 4′-methylchevalone E (4), respectively. This study demonstrates the critical role of endophytic fungi in enhancing structural diversity. Conclusions: These findings provide valuable insights into the compatibility of pathway combinations and the interchangeability of terpene cyclases derived from endophytic fungi in medicinal plants, which advanced the understanding of meroditerpenoid biosynthesis and highlighted the importance of endophytic fungi in drug discovery.

Hepatocellular carcinoma (HCC) is one of the common and fatal malignant tumors worldwide, and the burden of HCC is particularly severe in China. Physiologically, the blood supply to healthy liver is mainly from the portal vein, supplemented by the hepatic artery. While in the development of HCC, the main source of blood supply to HCC is changed from the portal vein to the hepatic artery. The characteristics of HCC vascularization are important for imaging, surgery, interventional therapy, targeted therapy, etc. Even in the future, with the development of radiation therapy technology, such as proton and heavy ion therapy and artificial intelligence technology, the dynamic changes in HCC blood perfusion can be used as a new biomarker of tumor activity to provide accurate information on the intensity modulation of radiotherapy, so that accurate measurements of HCC blood perfusion is of great significance in guiding the diagnosis and treatment of HCC. The technologies for measurement of HCC blood perfusion have developed from invasive techniques, such as inert gas scavenging, electromagnetic flowmeter, and radionuclide-labeled erythrocyte elution in the middle of the last century to the present non-invasive techniques of CT. With the development of CT imaging technology in the last 30 years, the CT-based imaging technology can assess the status of organ and tissue perfusion relatively easily and accurately. In this paper, the various CT measurement techniques of blood perfusion in HCC were categorized into three types: semi-quantitative technique, relative quantitative technique, and absolute quantitative technique. Their basic principle, scanning methods, and clinical applications were discussed to provide a reference for the diagnosis and treatment of HCC.

Hepatocellular carcinoma (HCC) is one of the common and fatal malignant tumors worldwide, and the burden of HCC is particularly severe in China. Physiologically, the blood supply to healthy liver is mainly from the portal vein, supplemented by the hepatic artery. While in the development of HCC, the main source of blood supply to HCC is changed from the portal vein to the hepatic artery. The characteristics of HCC vascularization are important for imaging, surgery, interventional therapy, targeted therapy, etc. Even in the future, with the development of radiation therapy technology, such as proton and heavy ion therapy and artificial intelligence technology, the dynamic changes in HCC blood perfusion can be used as a new biomarker of tumor activity to provide accurate information on the intensity modulation of radiotherapy, so that accurate measurements of HCC blood perfusion is of great significance in guiding the diagnosis and treatment of HCC. The technologies for measurement of HCC blood perfusion have developed from invasive techniques, such as inert gas scavenging, electromagnetic flowmeter, and radionuclide-labeled erythrocyte elution in the middle of the last century to the present non-invasive techniques of CT. With the development of CT imaging technology in the last 30 years, the CT-based imaging technology can assess the status of organ and tissue perfusion relatively easily and accurately. In this paper, the various CT measurement techniques of blood perfusion in HCC were categorized into three types: semi-quantitative technique, relative quantitative technique, and absolute quantitative technique. Their basic principle, scanning methods, and clinical applications were discussed to provide a reference for the diagnosis and treatment of HCC.

Objective To prepare decellularized scaffolds from rabbit cartilage at various concentrations and assess their physicochemical properties and compatibility with stem cells to provide an experimental basis for cartilage repair.Methods Bone marrow mesenchymal stem cells(BMSCs)were cultured using the Percoll density gradient separation method,and this was followed by flow cytometric analysis and testing of their osteogenic and chondrogenic differentiation capabilities.Cartilage pieces were excised from rabbit knees and hip joints and subjected to physical crushing,repeated freeze-thaw cycles,and mixed enzymatic digestion for decellularization.To compare and observe the physicochemical properties of the decellularized scaffolds at different concentrations,three groups of scaffolds(labelwd A,B,and C)were designed with concentrations of 100％,50％and 30％,with three replicates each.Third-generation PKH26-labeled BMSCs were seeded onto optimally concentrated scaffolds and cultured for 1 week to observe cell growth.Results Flow cytometry detected BMSC surface antigens with positive expression of CD44 and CD90 and negative expression of CD45.Osteogenic induction stained with alizarin red showed red calcific nodules,and chondrogenic induction stained with alcian blue showed blue cartilaginous nodules.No apparent cell morphology was observed in the three groups of scaffolds stained with hematoxylin-eosin,and toluidine blue.There was a significant difference in DNA concentration between decellularized samples and non-decellularized scaffolds(P＜0.05).The content of glycosaminoglycans was slightly lower than the normal values.Significant differences were observed between the three groups of scaffolds in terms of pore size,water absorption,porosity,tensile strength,and Young's modulus(P＜0.05).After co-cultivation of stem cells with the scaffolds,cell adhesion was found to be good.Conclusions Percoll density gradient separation can obtain high-purity rabbit BMSCs,and the mixed decellularization method is superior.Group B scaffolds were the most suitable for tissue-engineered cartilage repair.BMSCs cultured in vitro grew well on Group B scaffolds.

The study adopted muscle injection of pVAX1-SP-GHRH(1-44)expression plasmid and electrostimulation to determine its effects on mouse growth and sow production performance.One hundred and fifty four-week-old C57 BL/6 female mice were randomly divided into 6 groups of 5 replicates each.Muscle single-injection followed by electrostimulation was performed.The con-trol group received an empty plasmid injection(80 μg/kg),while the treatment groups received pVAX1-SP-GHRH(1-44)plasmid injections(20,40,80,120,160 μg/kg).Twenty healthy preg-nant sows were randomly divided into 2 groups,each with 10 sows.Electrostimulation treatment was applied to the semimembranosus muscle of the pregnant sows after a single injection.The con-trol group received physiological saline injection,while the plasmid group received a 2 mg pVAX1-SP-GHRH(1-44)expression plasmid injection.Mouse weight,feed intake,and serum GHRH and IGF-1 levels were measured at days 0,7,14,21,and 28 after injection.Pregnant sows were bled via the tail vein at days 0,14,28,and 42 after injection,and their serum was separated to measure serum GHRH and IGF-1 levels.The birth weight,placental weight,number of piglets born,number of healthy piglets,number of weak piglets,number of deformed piglets,number of stillborn piglets,and number of mummified piglets were recorded at day 14.The mouse study re-sults showed that muscle injection of pVAX1-SP-GHRH(1-44)plasmid followed by electrostim-ulation could promote mouse feeding and increase weight gain(P＜0.05),significantly increase mouse serum GHRH and IGF-1 levels(P＜0.05),and maintain its effects until day 21.The results of the pregnant sow study showed that the average birth weight of the piglets in the plasmid group was significantly increased(P＜0.01),and the placenta weight was significantly increased(P＜0.05).The serum GHRH and IGF-1 concentrations in the plasmid group sows were significantly increased(P＜0.01).The study results showed that muscle injection of pVAX1-SP-GHRH(1-44)expression plasmid followed by electrostimulation could promote mouse feeding and increase weight gain,and also significantly improve the average birth weight and placental weight of the piglets in pregnant sows.

Objective:To explore the pathogenesis of flunarizine-induced parkinsonism from gut-brain axis perspective.Methods:Thirty male C57BL/6 mice were randomly divided into control group and flunarizine group ( n=15). Mice in the control group were given 0.1 mL 50% polyethylene glycol 400+50% saline by gavage once/d for 2 weeks, while mice in the flunarizine group were given 6 mg/mL flunarizine+50% polyethylene glycol 400+50% saline by gavage at a daily dose of 30 mg/kg for 2 weeks. Body mass was recorded 1, 3, 5, 7, 10 and 14 d after drug administration, and motor function was assessed by rotarod test 14 d after drug administration; 16s RNA sequencing was performed in the feces to observe the intestinal flora; intestinal transit function was detected by Evans blue by gavage; and then, the mice were sacrificed and homogenate or frozen sections (brain and intestinal tissues) were prepared; dopamine-ergic neuron expression was detected by Western blotting; RT-qPCR was applied to detect the expressions of inflammatory factors in the substantia nigra, and immunofluorescent staining was used to detect the expressions of ZO-1 and Claudin-5 in the intestinal epithelial tissues. Results:Compared with the control group, the flunarizine group had lower body mass ratio 1, 3, 5, 7, 10 and 14 d after drug administration (ratio to body mass before drug administration). Compared with the control group, the flunarizine group had significantly shortened residence time in rod rotating and lower rotational speed when falling ( P<0.05). Compared with the control group, the flunarizine group had decreased tyrosine hydroxylase protein in the substantia nigra without significant difference ( P>0.05). Compared with the control group, the flunarizine group had significantly increased interleukin-6 and tumor necrosis factor-α in the substantia nigra (1.00±0.00 vs. 2.79±0.83; 1.00±0.00 vs. 3.39±1.37), significantly lower intestinal Evans blue propulsion rate (80.67%±4.51% vs. 50.67%±6.03%), and statistically decreased ZO-1 and Claudin-5 expressions in the colonic epithelial tissues (27.01±1.41 vs. 16.32±2.83; 37.00±2.80 vs. 24.52±2.12, P<0.05). Totally, 576 microorganisms were noted in both control group and flunarizine group, 744 in the control group alone, and 634 in the flunarizine group alone. The intestinal flora β diversity indices in the 2 groups were significantly different based on weighted Unifrac-principle coordinates analysis (PCoA, PCoA1: 39.88%; PCoA2: 30.69%). Compared with the control group, the microbial colony structure of mice in flunarizine group was dominated by phylum thick-walled bacteria and phylum warty microbacteria, and by families Muribaculaceae, Lachnospiraceae and Akkermansiaceae. Compared with the control group, the flunarizine group had significantly decreased relative abundance of Ackermannia spp. and Lactobacillus spp. in the intestinal flora ( P<0.05). Conclusion:Flunarizine may contribute to the pathogenesis of DIP by causing structural disturbances in the intestinal flora and inducing neuroinflammation based on the gut-brain axis.

Objective To analyze thein vivo three-dimensional dose verification using electronic portal imaging device(EIVD)for intensity-modulated radiotherapy(IMRT)of cervical cancer for investigating the differences between the measured and planned doses,and explore the optimal threshold for gamma passing rate in EIVD quality control based on dosimetric sensitivity.Methods A retrospective analysis was conducted on a cohort of 45 patients with cervical cancer who underwent IMRT at Women's Hospital,School of Medicine,Zhejiang University.During the treatment,all patients underwent EIVD to obtain the measured doses.The passing rate was analyzed using global gamma criteria of 2 mm/2%,2 mm/3%,and 3 mm/3%.Additionally,dose-volume histogram parameters were utilized to evaluate any differences between the measured and planned doses.Pearson correlation analysis was employed to investigate the relationship between the gamma passing rate and dosimetric differences.Furthermore,receiver operating characteristic(ROC)curve was generated to determine the optimal threshold for the gamma passing rate.Results The average gamma passing rates for the criteria of 2 mm/2%,2 mm/3%,and 3 mm/3%were 83.07%±5.25%,91.69%±3.52%,and 95.02%±2.46%,respectively.The Dmean deviation between EIVD measurement and planned dose in the planning target area was 2.43%(P=0.016),while the Dmean deviations in the bladder,rectum,and small intestine were 0.35%,0.46%,and 0.30%,respectively(P>0.05).Pearson analysis revealed a strong correlation between the 3 gamma indexes and dosimetric differences in the PTV(r>0.7),but a weak correlation with organs-at-risk(r<0.7).ROC analysis indicated that the optimal gamma passing rate thresholds for the criteria of 2 mm/2%,2 mm/3%,and 3 mm/3%were 79.06%,90.04%,and 94.19%,respectively.Conclusion The implementation of EIVD can ensure the accuracy of dose delivery within the PTV during IMRT for cervical cancer.Moreover,establishing a gamma passing rate threshold provides a valuable clinical basis for subsequent adaptive IMRT for cervical cancer.