Building Flexible Escherichia coli Modules for Bifunctionalizing n-Octanol: The Byproduct of Oleic Acid Biorefinery.

Artificial biorefinery of oleic acid into 1,10-decanedioic acid represents a revolutionizing route to the sustainable production of chemically difficult-to-make bifunctional chemicals. However, the carbon atom economy is extremely low (56%) due to the formation of unifunctional n-octanol. Here, we report a panel of recombinant Escherichia coli modules for diverse bifunctionalization, where the desired genetic parts are well distributed into different modules that can be flexibly combined in a plug-and-play manner. The designed ω-functionalizing modules could achieve ω-hydroxylation, consecutive ω-oxidation, or ω-amination of n-octanoic acid. By integrating these advanced modules with the reported oleic acid-cleaving modules, high-value C8 and C10 products, including ω-hydroxy acid, ω-amino acid, and α,ω-dicarboxylic acid, were produced with 100% carbon atom economy. These ω-functionalizing modules enabled the complete use of all of the carbon atoms from oleic acid (released from plant oil) for the green synthesis of structurally diverse bifunctional chemicals.

Carving the Active Site of CYP153A7 Monooxygenase for Improving Terminal Hydroxylation of Medium-Chain Fatty Acids.

The P450-mediated terminal hydroxylation of non-activated C-H bonds is a chemically challenging reaction. CYP153A7 monooxygenase, discovered in Sphingomonas sp. HXN200, belongs to the CYP153A subfamily and shows a pronounced terminal selectivity. Herein, we report the significantly improved terminal hydroxylation activity of CYP153A7 by redesign of the substrate binding pocket based on molecular docking of CYP153A7-C8:0 and sequence alignments. Some of the resultant single mutants were advantageous over the wild-type enzyme with higher reaction rates, achieving a complete conversion of n-octanoic acid (C8:0, 1 mM) in a shorter time period. Especially, a single-mutation variant, D258E, showed 3.8-fold higher catalytic efficiency than the wild type toward the terminal hydroxylation of medium-chain fatty acid C8:0 to the high value-added product 8-hydroxyoctanoic acid.

Effect of Amino Acid Motifs in Integrin β3 Cytoplasmic Tail on αⅡbβ3-Mediated Cell function in 293T cell models / 中国实验血液学杂志

OBJECTIVE@#To establish 293T cell lines stably expressing Calpain-cleavage related α3 cytoplasmic tail mutants, and to explore the effect of amino acid motifs in integrin β3 cytoplasmic tail on αⅡbβ3-mediated cell function.@*METHODS@#293T cell lines stably co-expressing human wild type integrin αⅡb and full length β3 or mutant β3, including β3-ΔNITY (β3 cytoplasmic tail NITY motif deleted), β3-Δ754 (β3 cytoplasmic tail TNITYRGT motif deleted) and β3-Δ759 (β3 cytoplasmic tail RGT motif deleted) were established. Spreading and adhesion of these stable cell lines on immobilized fibrinogen were tested.@*RESULTS@#293T-αⅡbβ3ΔNITY, 293T-αⅡbβ3Δ754, 293T-αⅡbβ3Δ759 and 293T-αⅡbβ3 cell lines were successfully established. Compared with the 293T cells, 293T-αⅡbβ3 cells which expressed full β3, possessed well adhesion and spread ability on immobilized fibrinogen, suggesting it can be as a surrogate for platelet. Compared with 293T-αⅡbβ3 cells, the 293T-αⅡbβ3ΔNITY cells showed a partial impairment of adhesion and spreadability on immobilized fibrinogen. while the 293T-αⅡbβ3Δ754 cells and 293T-αⅡbβ3Δ759 cells failed to adhere or spread on immobilized fibrinogen.@*CONCLUSION@#To the cell spreading function mediated by integrin β3, RGT motif is vital, while NITY can be dispensable. These established 293T cell lines stably expressing different β3 mutants provide a solid basis for a further analysis of mass spectrometry.

Effect of Carfilzomib on Proliferation and Apoptosis of Mantle Cell Lymphoma Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of Carfilzomib on mantle cell lymphoma (MCL), and to compare with effect of Bortezomib.@*METHODS@#The Jeko-1 cells and primary MCL cells were treated with Carfilzomib for 24, 48 and 72 h, then the inhibitory rate was detected using CCK-8. Lymphocytes derived from healthy volunteer were served as cell controls. Bortezomib and Cyclophosphamide (CTX) were served as medicinal controls. At the same time, the apoptosis of cells treated with different drugs was detected using flow cytometry.@*RESULTS@#The inhibitory effect of Carfilzomib on Jeko-1 cells and primary MCL cells was exhibited with time-dependent and concentration-dependent manners (P＜0.01, r=0.393, r=0.650, rJ=0.473, r=0.417), but the effect on lymphocytes derived from healthy volunteer only showed time-dependence (P＜0.01, r=0.928). Under the same concentration, Carfilzomib exhibited the proliferation Jeko-1 cells stronger than Bortezomib (P＜0.01), but the same inhibition on primary MCL cells was not significantly different from that on lymphocytes derived from healthy volunteer (P＞0.05). Under clinical recommended concentration, Carfilzomib had a stronger inhibitory effect on primary MCL cells than that of Bortezomib (P＜0.01). Cell apoptosis assay showed that under the same concentration the ability of Carfilzomib to induce cell apoptosis was significantly stronger than that of Bortezomib (P＜0.05).@*CONCLUSION@#Carfilzomib can inhibit the growth of MCL cells, its inhibitory rate on the MCL cells is higher than that of Bortezomib.

Relationship between low basal metabolic rate and mortality in older adults with hip fractures / 中国组织工程研究

BACKGROUND: Basal metabolic rate (BMR) is an important indicator of human energy metabolism, and low BMR leads to the dysfunction of liver and kidney. Low BMR is usually found in patients with hip fractures, but there is a lack of study on the relationship between mortality of hip fracture and low BMR. OBJECTIVE: To investigate the effect of low BMR on the 1-year mortality in older adults with hip fractures. METHODS: Totally 507 patients with hip fractures aged more than 60 years from January 2014 to March 2016 were included in this retrospective study. Age, sex, surgery or not, surgical pathway, duration from injury to surgery, hospitalized pulmonary infection, number and kind of comorbidities, and 1-year mortality were recorded. BMR on admission was recorded, and multiple Logistic regression analysis was applied. RESULTS AND CONCLUSION: All patients were followed up for 13-15 months, and the 1-year mortality was 13.41% (68/507). The mortality in the low BMR group was significantly higher than that in the non-low BMR group (P ＜ 0.05). Logistic regression analysis showed that older age, conventional treatment, number of combined medical diseases, hospitalized pulmonary infection, and low BMR are risk factors for 1-year mortality in older adults with hip fracture. These results imply that low BMR is strongly associated with 1-year mortality in older adults with hip fracture. BMR can reflect the nutritional status, neuroendocrine, cellular and energy metabolism. Thereafter, for older adults with hip fractures and low BMI, nutrition therapy, re-warming, and endocrine therapy may help reduce the trauma-induced mortality.

Dental pulp repair with dental pulp stem cells by construction of tissue-engineered dentin-pulp complex / 中国组织工程研究

BACKGROUND: Studies have shown that dental pulp stem cells have high proliferation and multi-directional differentiation abilities and can differentiate into a variety of cells under certain conditions. At present, the use of dental pulp stem cells to construct tissue-engineered dentin-pulp complex is expected to become a new strategy for human dental defect repair . OBJECTIVE: To observe the effect of dental pulp stem cells on the repair of rat tooth defects by construction of tissue-engineered dentin-pulp complex. METHODS: Twenty-four Sprague-Dawley rats were used to make animal models with dental pulp removal, and then model rats were randomly divided into model group and transplantation group. Rats in the transplantation group were subjected to tissue-engineered dentin-pulp complex transplantation, and those in the model group given no treatment. Tooth samples were collected at 3, 5, 7 weeks post transplantation and observed using hematoxylin-eosin staining and immunofluorescence staining. The dentin thickness of rats was measured by Image Pro Plus 6.0 image software system. RESULTS AND CONCLUSION: (1) Dental pulp cells was mostly spindle/oval-shaped and partially polygonal. The third generation of cells with long spindle shape showed fibrous growth and uniform morphology. Findings from immunohistochemical staining showed spindle-shaped deep-colored cells with oval nuclei stained as dark blue were identified as fibroblast-like cells, and were positire for vimtin. (2) Findings from hematoxylin-eosin staining showed vacuolar degeneration of the cells, and hbdestroyed pulp tissue and debris, irregular cord-like tissue, and a large amount of red blood cells and inflammatory cells in the pulp cavity, accompanied by clearly visible vascular dilation. Seven weeks after transplantation, a bundle of odontoblasts were visible in the matrix-like tissues of the dentin, and there was a distinct boundary between the original dentin and regenerated dentin. (3) Findings from immunofluorescent staining showed that after dentin-pulp complex transplantation, the number of cells in the pulp cavity increased significantly at 3 weeks, and there was also a substantial increase in dental pulp cells at 5 weeks that were distributed on the wall of the pulp cavity. Compared with the model group, the dentin thickness in the transplantation group was significantly higher at each time after transplantation (P < 0.05), and in the transplantation group, there was also a significant difference in the dentin thickness at different time points (P < 0.05). To conclude, the tissue-engineered dentin-pulp complex can promote dentin regeneration and repair.

Effects of zinc on biological behavior of hepatocellular carcinoma cell line BEL-7404 / 中国病理生理杂志

AIM:To observe the effects of exogenous zinc on the biological behavior of hepatocellular carcino -ma ( HCC) cell line BEL-7404.METHODS: BEL-7404 cells were cultured with zinc sulfate at various concentrations . The intracellular concentration of zinc , cell viability , cell cycle , cell apoptosis and migration and invasion abilities were measured by TSQ fluorescent probe , MTT assay, DNA ploid analysis, acridine orange/ethidium bromide fluorescence stai-ning and Transwell assay , respectively .The mRNA and protein expression levels of albumin in the BEL-7404 cells were determined by real-time PCR and Western blot , respectively .RESULTS: With the elevated concentration of zinc in cul-ture condition, the concentration of zinc in the BEL-7404 cells was increased (P<0.05).The cell viability and migration and invasion abilities were decreased , while the apoptotic rate was increased (P<0.05).The cells in G0/G1 phase were decreased, while the cells in G2/M phase were increased.Additionally, the mRNA and protein expression of albumin also increased (P<0.05).CONCLUSION:The zinc ion inhibits the cell viability as well as migration and invasion abilities , blocks the cells in G 2/M phase , and may reduce cell malignant phenotype .

[Study on ultrastructure of cardioprotection of ramipril against ischemia/reperfusion injury in diabetic rats].

AIM: To investigate the effects of ramipril on myocardial ischemia/reperfusion injury in diabetic rats, and to explore its mechanism according to the observation on myocardial ultrastructure. METHODS: Streptozotocin induced diabetic rats were divided randomly into three groups (n = 16): ischemia/reperfusion (I/R), ischemic preconditioning (IPC) and ramipril (RAM) group. Rats in RAM group were administered by RAM(1 mg x kg(-1) x d(-1)) orally for 4 weeks, the others were administered by normal saline. Then all rats were subjected to myocardial ischemia/ reperfusion injury. Rats in IPC group were preconditioned before ischemia. The ECG and the infarct size were examined. The changes of myocardial morphology were examined by light and electron microscopes. RESULTS: Compared with I/R group, the elevation of ST segment and the incidence of ventricular tachycardia and ventricular fibrillation during ischemia were significantly decreased, the infarct size at the end of reperfusion was remarkably reduced, the myocardial morphology were significantly improved, special structure of myofilaments and mitochondria remained clearly, blood vessels were unobstructed, injury of endothelium were decreased in PC and RAM groups. CONCLUSION: Ramipril administered for 4 weeks induces myocardial protection in diabetic rats, which is similar to that of IPC. The mechanism may be involved in protection of cardiocytes and mitochondria, and improvement of endothelial function.

[Evaluation of midazolam intravenous sedated patient's comfort degree in mandibular third molar surgery].

OBJECTIVE: To evaluate the clinical efficacy and safety of continuous low-flow intravenous infusion of midazolam sedation in mandibular third molar surgery. METHODS: Fifty healthy patients with symmetrically placed impacted bilateral mandibular third molars were included in this self controlled, randomized clinical study. Degree of comfort (their actual current anxiety level) was assessed using a visual analogue scale (VAS) of pain and anxiety. Patients' satisfaction and degree of amnesia were also evaluated. Vital signs and oxygen saturation were recorded. RESULTS: Low dose midazolam sedation obviously increased the degree of patients' comfort and satisfaction. Vital signs and oxygen saturation levels did not differ significantly between the two groups. CONCLUSIONS: Midazolam as an intravenous sedation agent in mandibular third molar surgery showed satisfactory effect on patients with mild dental fear.