Construction of a column-line graph for predicting the probability of survival in early-stage elderly HER2-positive breast cancer based on the SEER database / 中国临床药理学与治疗学

AIM: To construct column-line plots to predict survival in elderly patients with early-stage HER2-positive breast cancer using the Surveillance, Epidemiology and End Results (SEER) database. METHODS: 5 220 (based on the era of single-targeted therapy) and 1 176 (based on the era of dual-targeted therapy) patients screened in the SEER database were randomized into a training group and an internal validation group. COX proportional risk regression was used to screen survival-related predictors and build a column-line graphical model, and the accuracy and utility of the model were tested using the consistency index (C-index), calibration curves, and time-dependent ROC curves. Patients receiving chemotherapy and non-chemotherapy were statistically paired using two-group propensity score matching, and subgroup analyses were performed on the screened variables. RESULTS: The single-targeted therapy era line graph was constructed from seven variables: age, marital status, T-stage, N-stage, surgery, chemotherapy, and radiotherapy. The dual-targeted therapy era line graph was constructed from five variables: age, AJCC staging, surgery, chemotherapy, and radiotherapy. The results of the subgroup analysis showed that older HER2-positive breast cancer patients who received chemotherapy had better OS. CONCLUSION: Based on the SEER database, an accurate column-line graph predicting survival in elderly patients with early-stage HER2-positive breast cancer was established and validated. This study suggests that chemotherapy increases survival benefit in elderly patients.

Clinicopathological features of intravascular large B-cell lymphoma and collision tumors of five cases / 中华病理学杂志

Objective: To investigate the clinicopathological characteristics, diagnosis and differential diagnosis of intravascular large B-cell lymphoma (IVLBCL) and its collision tumors. Methods: Five cases of IVLBCL were collected, including 2 cases of collision tumors, and 1 case complicated with liver cirrhosis. The morphology and immunophenotype were analyzed. The related literature was reviewed. Results: There were 2 females and 3 males, aged from 53 to 73 years, with a median age of 65 years. The tumors were located in the lower extremities, right cerebellar hemisphere, left kidney, bilateral nasal cavity, and liver, respectively. Cases 2 and 3 were incidentally found in meningioma and renal cell carcinoma tissues, respectively. Case 5 had a background of liver cirrhosis. Morphologically, atypical large lymphoid cells were located in small blood vessels and capillary lumen, with little cytoplasm, hyperchromasia, prominent nucleoli, and obvious mitotic figures. Immunohistochemically, the IVLBCL tumor cells expressed CD20 and PAX5; 2 cases were CD5 positive. One of the 5 cases was GCB phenotype, and 4 cases were non-GCB phenotype. All cases expressed C-MYC (positive rate was 10%-40%). PD-L1 was positive in 4 cases (positive rate was 60%-90%). Ki-67 proliferation index was 70%-90%. CKpan, CD3, TDT, and CD34 were negative. In case 2, meningioma cells were positive for PR, EMA, and vimentin, but negative for CKpan and PD-L1. In case 3, renal carcinoma cells were positive for CKpan, PAX8, EMA, vimentin, CAⅨ and CD10, while PD-L1 was negative. No EBER expression (by in situ hybridization) or C-MYC gene translocation (FISH, break-apart probe) was detected in any of the 5 cases. Three patients were followed up, and all died within 1-13 months. Conclusions: IVLBCL is a highly aggressive lymphoma, with occult clinical manifestations and poor prognosis. Collision tumors of IVLBCL are extremely rare. A better understanding of IVLBCL would help pathologists avoid misdiagnoses.

Exosome-Transmitted miR-224-5p Promotes Colorectal Cancer Cell Proliferation via Targeting ULK2 in p53-Dependent Manner / 生物医学与环境科学（英文）

OBJECTIVE@#To investigate the role and molecular mechanism of exosomal miR-224-5p in colorectal cancer (CRC).@*METHODS@#The miR-224-5p expression in CRC patient tissues and cell-derived exosomes was measured by laser capture microdissection and qRT-PCR, respectively. Dual-luciferase reporter gene assay was used to determine the target gene of miR-224-5p. The protein expressions of p53 and unc-51 like kinase 2 (ULK2) in CRC cells were detected by western blot. Flow cytometry was used to detect cell cycle and apoptosis. Cell proliferation was measured by CCK8 and EdU assay.@*RESULTS@#The miR-224-5p expression was upregulated in CRC tissues and increased progressively with the rise of CRC stage. CRC cells secreted extracellular miR-224-5p mainly in an exosome-dependent manner, and then miR-224-5p could be transferred to surrounding tumor cells to regulate cell proliferation in the form of autocrine or paracrine. Moreover, ULK2 was characterized as a direct target of miR-224-5p and was downregulated in CRC tissues. Interestingly, ULK2 inhibited CRC cell proliferation in a p53-dependent manner. Furthermore, exosome-derived miR-224-5p partially reversed the proliferation regulation of ULK2 on CRC cells.@*CONCLUSION@#Our findings demonstrate that exosome-transmitted miR-224-5p promotes p53-dependent cell proliferation by targeting ULK2 in CRC, which may offer promising targets for CRC prevention and therapy.

Interventional effect and mechanism of 1，8-cineole on pancreatic β cell ferroptosis induced by type 2 diabetes / 中国药房

OBJECTIVE To study the interventional effect and mechanism of 1，8-cineole on pancreatic β cell ferroptosis induced by type 2 diabetes. METHODS In vitro ferroptosis model was established in pancreatic β cells of mice by using high glucose. The effects of low-dose and high-dose 1，8-cineole （0.25， 0.5 μmol/L） on the level of Fe2+ in pancreatic β cells were investigated. The effects of 1，8-cineole （0.5 μmol/L） combined with ferroptosis inducer Erastin （20 μmol/L） and ferroptosis inhibitor Ferrostatin-1 （20 μmol/L） on the protein expressions of glutathione peroxidase-4 （GPX4） and cyclooxygenase-2 （COX2） were also detected. The type 2 diabetes model mice were established by feeding high-sugar and high-fat diet combined with intraperitoneal injection of streptozotocin. The effects of low-dose and high-dose 1，8-cineole （50， 200 mg/kg） on the pathological morphology of pancreatic tissue， the content of iron as well as the protein expressions of GPX4 and COX2 were investigated. RESULTS The results of the cell experiment showed that compared with the model group， pretreatment with 1，8-cineole significantly reduced intracellular Fe2+ levels and upregulated GPX4 protein expression， while downregulated COX2 protein expression in pancreatic β cells （P＜0.05）. After combining with Ferrostatin-1， the expression trends of the above two proteins were the same， while there was no statistically significant difference after combining with Erastin. The results of animal experiments showed that compared with the model group， after intervention with 1，8-cineole， the structure of the pancreatic islets in mice recovered intact and their morphology improved； the iron content of pancreatic tissue and protein expression of COX2 were decreased significantly （P＜0.05）， while protein expression of GPX4 was increased significantly （P＜0.05）. CONCLUSIONS 1，8-cineole could ameliorate pancreatic β cell injury induced by diabetes， the mechanism of which may be related to reducing intracellular iron deposition and regulating ferroptosis-related proteins.

Research progress on potential therapeutic targets of chronic cough / 中国药理学通报

Chronic cough is caused by low levels of heat, mechanical or chemical exposure, which is characterized by the disorders of channels and receptors in neuroregulation such as the peripheral and central nerves. Potential regulatory targets of peripheral nerves include P2X3 receptors and transient receptor potential channels, while potential regulatory targets of central nerves include voltage-gated sodium channels, neurokinin-1 receptors, α-7acetylcholine receptors and gamma aminobutyric acid receptors. This paper focuses on the principle and clinical research evidence of several ongoing targeted therapy strategies, in order to provide new ideas for the development of drugs for the treatment of chronic cough.

Piriform sinus hamartoma in children: a case report and literature review / 临床耳鼻咽喉头颈外科杂志

Objective:To investigate the clinical manifestations and treatment of laryngopharynx hamartoma in children. Methods:The clinical data of a child with piriform sinus hamartoma treated in our hospital were analyzed retrospectively. The age, gender, clinical manifestations, auxiliary examination, location of the tumor and surgical methods were analyzed. Results:The patient had a good prognosis after surgery, and no tumor recurrence was found after 1 year of follow-up. Conclusion:Laryngopharynx hamartoma is rare in children. It should be considered in children with laryngeal dysfunction and upper airway obstruction. Complete resection of the tumor is the key to postoperative recurrence.

Highly efficient production of L-valine by multiplex metabolic engineering of Corynebacterium glutamicum / 生物工程学报

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.

Regulation of intracellular level of ATP and NADH in Escherichia coli to promote succinic acid production / 生物工程学报

Succinic acid is an important C4 platform chemical that is widely used in food, chemical, medicine sectors. The bottleneck of fermentative production of succinic acid by engineered Escherichia coli is the imbalance of intracellular cofactors, which often leads to accumulation of by-products, lower yield and low productivity. Stoichiometric analysis indicated that an efficient production of succinic acid by E. coli FMME-N-26 under micro-aeration conditions might be achieved when the TCA cycle provides enough ATP and NADH for the r-TCA pathway. In order to promote succinic acid production, a serial of metabolic engineering strategies include reducing ATP consumption, strengthening ATP synthesis, blocking NADH competitive pathway and constructing NADH complementary pathway were developed. As result, an engineered E. coli FW-17 capable of producing 139.52 g/L succinic acid and 1.40 g/L acetic acid in 5 L fermenter, which were 17.81% higher and 67.59% lower than that of the control strain, was developed. Further scale-up experiments were carried out in a 1 000 L fermenter, and the titer of succinic acid and acetic acid were 140.2 g/L and 1.38 g/L, respectively.

Clinical blood dispatching between hospitals in Shijiazhuang / 中国输血杂志

【Objective】 To analyze the blood dispatching of hospitals in Shijiazhuang area, in order to provide reference for blood dispatching policy of hospitals and ensure clinical blood supply. 【Methods】 The hospital blood dispatching data from 2018 to 2021 were queried through the blood center information management system (SHINOW9.5) and TMIS system, and the blood dispatching volume, frequency, variety and blood type distribution of hospitals at all levels were analyzed by SPSS statistical software. 【Results】 From 2018 to 2021, there were 1 196 times of blood dispatching in hospitals with a total volume of 4 648.5 U, showing a downward and then upward trend two years before and after the outbreak of COVID-19. As the main blood dispatching product, erythrocyte dispatching was 3 988 U, accounting for 85.79% of the total dispatching volume, with a dispatching rate of 2.99‰. The dispatching volume of red blood cells in secondary hospitals accounted for 86.13%.The dispatching rate of erythrocyte in secondary and tertiary hospitals was 1.03% and 0.06%, respectively, with significant difference(P<0.05). The dispatching rates of type A and AB red blood cells were 3.08‰ and 4.97‰, which were significantly different from those of type B and O red blood cells. 【Conclusion】 Blood dispatching has become an effective way to avoid blood waste and ensure emergency blood use in secondary and tertiary hospitals. In the actual operation, health administration department should strengthen supervision and hospitals should improve the blood dispatching process to ensure blood safety.

Genetic analysis of a child with atypical Hemolytic uremic syndrome and nephrotic-range proteinuria / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical characteristics and genetic etiology for a child with atypical Hemolytic uremic syndrome (aHUS) in conjunct with nephrotic level proteinuria.@*METHODS@#A child patient who had visited the Affiliated Hospital of Qingdao University on June 25, 2020 was selected as the study subject. Clinical data of the patient was collected. Whole exome sequencing (WES) was carried out for the child, and candidate variant was verified by Sanger sequencing of the child and his parents.@*RESULTS@#The child, an 8-month-old male, had presented mainly with edema, oliguria, hematuria, nephrotic level proteinuria, anemia, thrombocytopenia, increased creatinine and urea, hypercholesterolemia but normal complement levels. Genetic testing revealed that he has harbored compound heterozygous variants of the DGKE gene, namely c.12_18dupGAGGCGG (p.P7fs*37) and c.1042G>T (p.D348Y), which were respectively inherited from his father and mother. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variants were classified as likely pathogenic and variant of uncertain significance, respectively. By combining his clinical manifestations and results of genetic testing, the child was diagnosed with aHUS with nephrotic level proteinuria.@*CONCLUSION@#For infants and young children with aHUS in conjunct with nephrotic level proteinuria, variants of the DGKE gene should be screened. Above finding has expanded the mutational spectrum of the DGKE gene.

Naoluo Xintong Decoction activates caspase-1/Gasdermin D pathway to promote angiogenesis of rat brain microvascular endothelial cells after oxygen glucose deprivation/reperfusion injury / 南方医科大学学报

OBJECTIVE@#To investigate the effects of Naoluo Xintong Decoction (NLXTD) on pyroptosis and angiogenesis of brain microvascular endothelial cells (BMECs) and explore the possible mechanisms in rats with oxygen-glucose deprivation/ reperfusion (OGD/R).@*METHODS@#Rat BMECs with or without caspase-1 siRNA transfection were cultured in the presence of 10% medicated serum from NLXTD-treated rats (or blank serum) and exposed to OGD/R. CCK-8 assay, Transwell chamber assay, and tube formation assay were used to assess proliferation, migration, and tube-forming abilities of the cells. The activity of lactate dehydrogenase (LDH) in the culture supernatant was determined using a commercial assay kit, and the levels of inflammatory factors IL-1β and IL-18 were detected with ELISA. The cellular expressions of pro-caspase-1, caspase-1, NLRP3, Gasdermin D, and angiogenesis-related proteins VEGF and VEGFR2 were detected using Western blotting.@*RESULTS@#The BMECs showed obvious injuries after OGD/R exposure. Compared with the blank serum, the medicated serum significantly improved the cell viability, migration ability, and lumen-forming ability (P < 0.01) and lowered the levels of IL-1β and IL-18 and the LDH release (P < 0.01) of the cells with OGD/R exposure. Western blotting showed that in the BMECs exposed to OGD/R, the medicated serum strongly upregulated the expression of VEGF and VEGFR2 proteins (P < 0.01) and reduced the protein expressions of pro-caspase-1, caspase-1, NLRP3, and Gasdermin D (P < 0.01), and transfection of the cells with caspase-1 siRNA further promoted the expressions of VEGFR2 protein in the cells (P < 0.01).@*CONCLUSION@#NLXTD can improve the proliferation, migration, and tube- forming ability and promote angiogenesis of BMECs with OGD/R injury probably by inhibiting the caspase-1/Gasdermin D pathway in pyroptosis, alleviating cell injury, and upregulating the expressions of VEGF and VEGFR2.

Percutaneous pedicle screw fixation combined expandable tubular retractor in the treatment of spinal metastases / 北京大学学报(医学版)

OBJECTIVE@#To investigate the effectiveness of percutaneous pedicle screw fixation combined expandable tubular retractor in the treatment of patients with spinal metastases.@*METHODS@#In the study, 12 patients of spinal metastases treated with percutaneous pedicle screw fixation combined expandable tubular retractor in our hospital were retrospectively reviewed between June 2017 and October 2019. Among the 12 patients, 9 were males and 3 were females; the median age was 62.5 years [(65.1±2.9) years]. The decompression segment of 7 patients was located at the lower thoracic spine (including 1 patient with incomplete paraplegia) and the decompression segment of 5 patients was located at the lumbar spine; Tomita score was 6.0±0.6. Perioperative data of the patients were reviewed. Visual analog scale (VAS score), Karnofsky score, and Eastern Cooperative Oncology Group (ECOG) score were compared before and after surgery. The patient's survival, adjuvant treatment, and internal fixation failure were observed in the follow-up period.@*RESULTS@#All the 12 patients had a successful operation with percuta-neous pedicle screw fixation combined expandable tubular retractor. The average operative time, blood loss, and blood transfused of the patients were (247.0±14.6) min, (804.2±222.3) mL and (500.0±100.0) mL, respectively. The average amount of drainage was (240.8±79.3) mL. Drainage tubes were pulled out early postoperative [(3.2±0.3) d], allowing early mobilization. The patients discharged (7.8±0.8) d postoperative. All the patients were followed up for 6-30 months, and the average overall survival time was (13.6±2.4) months. During the follow-up period, 2 patients experienced screw displacement, the internal fixation was stable after conservative treatment and no revision surgery was performed. The VAS of the patients was 7.1±0.2 before surgery, which decreased to 2.3±0.1 and 2.8±0.4 at 3 and 6 months after surgery (P < 0.05). The Karnofsky score of the patients was 59.2±1.9 before surgery, which increased to 75.0±1.9 and 74.2±3.1 at 3 and 6 months after surgery (P < 0.05). The ECOG of the patients was 2.3±0.2 before surgery, which decreased to 1.7±0.1 and 1.7±0.2 at 3 and 6 months after surgery (P < 0.05).@*CONCLUSION@#For selected patients with spinal metastases, minimally invasive surgical treatment of spinal metastases (percutaneous pedicle screw internal fixation combined with expandable tubular retractor) can effectively relieve the clinical symptoms and improve the quality of life, with satisfactory clinical outcome.

Salvianolic acid B exerts its anti-tumor immunity by targeting USP2 and reducing the PD-L1 level / 药学学报

With the development of small-molecule immunotherapy drugs, its combination with the programmed cell death ligand 1/programmed cell death protein 1 (PD-L1/PD-1) antibodies would provide a new opportunity for cancer treatment. Therefore, targeting PD-L1/PD-1 axis by small-molecule drug is an attractive approach to enhance antitumor immunity and considered as the next generation of tumor immunotherapy. In the present study, we investigated the anti-tumor role of salvianolic acid B (SAB) by regulating the PD-L1 level in tumors. Changes of total PD-L1 and membrane PD-L1 levels were determined by Western blot, flow cytometry and PD-1/PD-L1 interaction assays. The expression of mRNA level of PD-L1 was detected by real-time PCR. The cytotoxicity of activated peripheral blood mononuclear cell (PBMC) cells toward co-cultured tumor cells was measured by cell impedance assay and crystal violet experiment. Surface plasma resonance technique was used to analyze the direct interaction between SAB and ubiquitin carboxyl-terminal hydrolase 2 (USP2). The antitumor effect of SAB in vivo was examined by C57BL/6 mice bearing MC38 xenograft tumor (all animal experiments were conducted in accordance with the Animal Ethics Committee of the Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences). Western blot and flow cytometry assay showed that SAB can significantly downregulate the abundance of PD-L1 in RKO and PC3 cells in dose- and time-dependent manner. PD-1/PD-L1 binding assay revealed that SAB reduces the binding of tumor cells to recombinant PD-1 protein. Mechanism studies revealed that SAB can bind directly to USP2 protein and inhibit its activity, thus promote the ubiquitin-proteasome pathway degradation of PD-L1 proteins. In addition, Cell impedance and crystal violet staining indicated that SAB enhances the killing activity of co-cultured PBMC cells toward tumor cells. MC38 tumor transplanted mouse experiments revealed that SAB treatment displayed significant suppression in the growth of MC38 tumor xenografts in C57BL/6 mice with an inhibition rate of 63.2% at 20 mg·kg-1. Our results demonstrate that SAB exerts its anti-tumor activity by direct binding and inhibiting the activity of USP2 and reducing the PD-L1 level. Our study provides an important material basis and scientific basis for the potential application of SAB in tumor immunotherapy drug targeting USP2-PD-L1 axis.

Efficacy and safety of acupuncture for polycystic ovary syndrome: An overview of systematic reviews / 中西医结合学报

BACKGROUND@#Polycystic ovary syndrome (PCOS) is the primary cause of anovulatory infertility, bringing serious harm to women's physical and mental health. Acupuncture may be an effective treatment for PCOS. However, systematic reviews (SRs) on the efficacy and safety of acupuncture for PCOS have reported inconsistent results, and the quality of these studies has not been adequately assessed.@*OBJECTIVE@#To summarize and evaluate the current evidence on the efficacy and safety of acupuncture for PCOS, as well as to assess the quality and risks of bias of the available SRs.@*SEARCH STRATEGY@#Nine electronic databases (Cochrane Library, MEDLINE, Embase, PsycINFO, CINAHL, Chinese National Knowledge Infrastructure, Wanfang Data, Chongqing VIP Chinese Science and Technology Periodical Database, and China Biology Medicine disc) were searched from their establishment to July 27, 2022. Based on the principle of combining subject words with text words, the search strategy was constructed around search terms for "acupuncture," "polycystic ovary syndrome," and "systematic review."@*INCLUSION CRITERIA@#SRs of randomized controlled trials that explored the efficacy and (or) safety of acupuncture for treating patients with PCOS were included.@*DATA EXTRACTION AND ANALYSIS@#Two authors independently extracted study data according to a predesigned form. Tools for evaluating the methodological quality, risk of bias, reporting quality, and confidence in study outcomes, including A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2), Risk of Bias in Systematic Reviews (ROBIS), Preferred Reporting Items for Systematic Reviews and Meta-analyses for Acupuncture (PRISMA-A), and the Grading of Recommendations Assessment, Development and Evaluation (GRADE), were used to score the included SRs.@*RESULTS@#A total of 885 studies were retrieved, and 11 eligible SRs were finally included in this review. The methodological quality of 2 SRs (18.18%) was low, while the other 9 SRs (81.82%) were scored as extremely low. Four SRs (36.36%) were considered to be of low risk of bias. As for reporting quality, the reporting completeness of 9 SRs (81.82%) was more than 70%. Concerning the confidence in study results, 2 study results were considered to have a high quality of evidence (3.13%), 14 (21.88%) a "moderate" quality, 28 (43.75%) a "low" quality, and 20 (31.24%) considered a "very low" quality. Descriptive analyses suggested that combining acupuncture with other medicines can effectively improve the clinical pregnancy rate (CPR) and ovulation rate, and reduce luteinizing hormone/follicle-stimulating hormone ratio, homeostasis model assessment of insulin resistance, and body mass index (BMI). When compared with medicine alone, acupuncture alone also can improve CPR. Further, when compared with no intervention, acupuncture had a better effect in promoting the recovery of menstrual cycle and reducing BMI. Acupuncture was reported to cause no adverse events or some adverse events without serious harm.@*CONCLUSION@#The efficacy and safety of acupuncture for PCOS remains uncertain due to the limitations and inconsistencies of current evidence. More high-quality studies are needed to support the use of acupuncture in PCOS.

Species identification of Ligustrum lucidum / 中国中药杂志

Ligustrum lucidum is a woody perennial plant of genus Ligustrum in family Oleaceae. Its dried fruit has high medicinal value. In this study, the authors evaluated the variability and species identification efficiency of three specific DAN barcodes(rbcL-accD, ycf1a, ycf1b) and four general DAN barcodes(matK, rbcL, trnH-psbA, ITS2) for a rapid and accurate molecular identification of Ligustrum species. The results revealed that matK, rbcL, trnH-psbA, ITS2 and ycf1a were inefficient for identifying the Ligustrum species, and a large number of insertions and deletions were observed in rbcL-accD sequence, which was thus unsuitable for development as specific barcode. The ycf1b-2 barcode had DNA barcoding gap and high success rate of PCR amplification and DNA sequencing, which was the most suitable DNA barcode for L. lucidum identification and achieved an accurate result. In addition, to optimize the DNA extraction experiment, the authors extracted and analyzed the DNA of the exocarp, mesocarp, endocarp and seed of L. lucidum fruit. It was found that seed was the most effective part for DNA extraction, where DNAs of high concentration and quality were obtained, meeting the needs of species identification. In this study, the experimental method for DNA extraction of L. lucidum was optimized, and the seed was determined as the optimal part for DNA extraction and ycf1b-2 was the specific DNA barcode for L. lucidum identification. This study laid a foundation for the market regulation of L. lucidum.

Metabolic engineering of Escherichia coli for adipic acid production / 生物工程学报

Adipic acid is a high-value-added dicarboxylic acid which is primarily used in the production of nylon-66 for manufacturing polyurethane foam and polyester resins. At present, the biosynthesis of adipic acid is hampered by its low production efficiency. By introducing the key enzymes of adipic acid reverse degradation pathway into a succinic acid overproducing strain Escherichia coli FMME N-2, an engineered E. coli JL00 capable of producing 0.34 g/L adipic acid was constructed. Subsequently, the expression level of the rate-limiting enzyme was optimized and the adipic acid titer in shake-flask fermentation increased to 0.87 g/L. Moreover, the supply of precursors was balanced by a combinatorial strategy consisting of deletion of sucD, over-expression of acs, and mutation of lpd, and the adipic acid titer of the resulting E. coli JL12 increased to 1.51 g/L. Finally, the fermentation process was optimized in a 5 L fermenter. After 72 h fed-batch fermentation, adipic acid titer reached 22.3 g/L with a yield of 0.25 g/g and a productivity of 0.31 g/(L·h). This work may serve as a technical reference for the biosynthesis of various dicarboxylic acids.

Modular engineering of Escherichia coli for high-level production of l-tryptophan / 生物工程学报

As an essential amino acid, l-tryptophan is widely used in food, feed and medicine sectors. Nowadays, microbial l-tryptophan production suffers from low productivity and yield. Here we construct a chassis E. coli TRP3 producing 11.80 g/L l-tryptophan, which was generated by knocking out the l-tryptophan operon repressor protein (trpR) and the l-tryptophan attenuator (trpL), and introducing the feedback-resistant mutant aroGfbr. On this basis, the l-tryptophan biosynthesis pathway was divided into three modules, including the central metabolic pathway module, the shikimic acid pathway to chorismate module and the chorismate to tryptophan module. Then we used promoter engineering approach to balance the three modules and obtained an engineered E. coli TRP9. After fed-batch cultures in a 5 L fermentor, tryptophan titer reached to 36.08 g/L, with a yield of 18.55%, which reached 81.7% of the maximum theoretical yield. The tryptophan producing strain with high yield laid a good foundation for large-scale production of tryptophan.

Metagenomic Analysis of Environmental Samples from Wildlife Rescue Station at Poyang Lake, China / 生物医学与环境科学（英文）

OBJECTIVE@#To improve the understanding of the virome and bacterial microbiome in the wildlife rescue station of Poyang Lake, China.@*METHODS@#Ten smear samples were collected in March 2019. Metagenomic sequencing was performed to delineate bacterial and viral diversity. Taxonomic analysis was performed using the Kraken2 and Bracken methods. A maximum-likelihood tree was constructed based on the RNA-dependent RNA polymerase (RdRp) region of picornavirus.@*RESULTS@#We identified 363 bacterial and 6 viral families. A significant difference in microbial and viral abundance was found between samples S01-S09 and S10. In S01-S09, members of Flavobacteriia and Gammaproteobacteria were the most prevalent, while in S10, the most prevalent bacteria class was Actinomycetia. Among S01-S09, members of Myoviridae and Herelleviridae were the most prevalent, while the dominant virus family of S10 was Picornaviridae. The full genome of the pigeon mesivirus-like virus (NC-BM-233) was recovered from S10 and contained an open reading frame of 8,124 nt. It showed the best hit to the pigeon mesivirus 2 polyprotein, with 84.10% amino acid identity. Phylogenetic analysis showed that RdRp clustered into Megrivirus B.@*CONCLUSION@#This study provides an initial assessment of the bacteria and viruses in the cage-smeared samples, broadens our knowledge of viral and bacterial diversity, and is a way to discover potential pathogens in wild birds.

Recent advances in diverse nanosystems for nitric oxide delivery in cancer therapy

Gas therapy has been proven to be a promising and advantageous treatment option for cancers. Studies have shown that nitric oxide (NO) is one of the smallest structurally significant gas molecules with great potential to suppress cancer. However, there is controversy and concern about its use as it exhibits the opposite physiological effects based on its levels in the tumor. Therefore, the anti-cancer mechanism of NO is the key to cancer treatment, and rationally designed NO delivery systems are crucial to the success of NO biomedical applications. This review summarizes the endogenous production of NO, its physiological mechanisms of action, the application of NO in cancer treatment, and nano-delivery systems for delivering NO donors. Moreover, it briefly reviews challenges in delivering NO from different nanoparticles and the issues associated with its combination treatment strategies. The advantages and challenges of various NO delivery platforms are recapitulated for possible transformation into clinical applications.

Periodontitis as a promoting factor of T2D: current evidence and mechanisms / 国际口腔科学杂志·英文版

Periodontitis is an infectious disease caused by an imbalance between the local microbiota and host immune response. Epidemiologically, periodontitis is closely related to the occurrence, development, and poor prognosis of T2D and is recognized as a potential risk factor for T2D. In recent years, increasing attention has been given to the role of the virulence factors produced by disorders of the subgingival microbiota in the pathological mechanism of T2D, including islet β-cell dysfunction and insulin resistance (IR). However, the related mechanisms have not been well summarized. This review highlights periodontitis-derived virulence factors, reviews how these stimuli directly or indirectly regulate islet β-cell dysfunction. The mechanisms by which IR is induced in insulin-targeting tissues (the liver, visceral adipose tissue, and skeletal muscle) are explained, clarifying the influence of periodontitis on the occurrence and development of T2D. In addition, the positive effects of periodontal therapy on T2D are overviewed. Finally, the limitations and prospects of the current research are discussed. In summary, periodontitis is worthy of attention as a promoting factor of T2D. Understanding on the effect of disseminated periodontitis-derived virulence factors on the T2D-related tissues and cells may provide new treatment options for reducing the risk of T2D associated with periodontitis.