Fed-batch cultures of recombinant Rchia pastoris were conducted for production of angiostatin. The whole fermentation included a growth phase on glycerol and an expression phase on methanol. When ammonium hydroxide solution was used to adjust pH, the cell growth during the expression phase was inhibited and the highest angiostatin concentration was 9.08 mg/L. Shake-flask cultures were carried out in media containing different quantities of ammonia. The results showed that ammonia had an obvious inhibition effect on the cell growth during the expression phase. Therefore KOH solution was used to adjust pH, and during the expression phase cells were able to grow and the highest angiostatin concentration reached 20 mg/L.

OBJECTIVETo express and purify the protein coded by the TRAF-type zinc finger domain of myasthenia gravis (MG)-related gene P9 (P9-ZFD) and to prepare P9-ZFD antiserum for detecting expression and subcellular distribution of P9-ZFD protein in the skeletal muscles of patient with MG.

METHODSThe cDNA encoding P9-ZFD was amplified by RT-PCR. The cloned P9-ZFD cDNA was ligated into pET24a, and the P9-ZFD recombinant protein was induced via E. coli. BL21 (DE3) and purified by histidine affinity chromatography. P9-ZFD antiserum was prepared and its titer and specificity were determined by ELISA and Western blot. Expression and subcellular distribution of P9-ZFD protein in the skeletal muscles of MG and control were studied.

RESULTSThe molecular weight of purified P9-ZFD protein was about 30 kD. Its purity was more than 95%. Antiserum specific for P9-ZFD was excellent. P9-ZFD protein is fully confined to the cytoplasm membrane of skeletal muscle cell of MG, obvious immunostaining was absent in the A, I, and Z bands of cytoplasm and no immunoreactivity was observed in the skeletal muscle cell of control.

CONCLUSIONP9-ZFD protein is expressed as a cytoplasm membrane-bound protein and has obvious distribution difference in the skeletal muscle cells of patient with MG and normal control.

Adult ; Cell Membrane ; metabolism ; Escherichia coli ; metabolism ; Female ; Humans ; Muscle Proteins ; biosynthesis ; genetics ; Muscle, Skeletal ; metabolism ; pathology ; Myasthenia Gravis ; metabolism ; Peptide Fragments ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; Transfection ; Zinc Fingers

Animals ; Animals, Newborn ; Cyclic AMP Response Element-Binding Protein ; analysis ; Hippocampus ; blood supply ; chemistry ; pathology ; Hypoxia-Ischemia, Brain ; physiopathology ; Immunohistochemistry ; Proto-Oncogene Proteins c-fos ; analysis ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; physiopathology ; Time Factors

A recombinant strain of Pichia pastoris with a phenotype of Muts was used to produce angiostatin in a 5-L fermentor. The methanol utilization ability of the present strain was weak, which resulted in extremely low growth rate and angiostatin productivity during the expression phase with methanol as the sole carbon source. To enhance the cell density and angiostatin expression level, mixed-carbon-source of glycerol-methanol was used in the expression phase. The methanol concentration was well controlled at 5 g/L by a methanol sensor and control system, and glycerol was continuously fed into the fermentor to achieve a higher cell density. 120 g/L of cells and 39 mg/L of angiostatin were reached at the end of fermentation which lasted 110 h. The mean specific cell growth rate in the expression phase was 0.01 h(-1), and the mean specific angiostatin productivity was 0.006 mg/(g x h). According to the data obtained in several runs of fermentation in which glycerol was fed at different rates, a higher mean specific angiostatin productivity was reached at the mean specific cell growth rate of 0.012 h(-1). To avoid the repression of angiostatin expression caused by residual glycerol and ethanol accumulation due to overfeeding of glycerol, glycerol addition was controlled to produce continuous oscillations in dissolved oxygen, because the change of dissolved oxygen concentration could deliver the information of available carbon source in the fermentation broth. Controlled glycerol feeding also avoided the problem of oxygen limitation brought by high cell density, and thus decreased the cooling requirement of the fermentor. Cell density reached 150 g/L at the end of fermentation, and angiostatin level reached 108 mg/L after an expression period of 96 h when the mean specific growth rate was maintained at 0.012 h(-1) by using the glycerol feeding strategy to result in the oscillations in dissolved oxygen. The mean specific angiostatin productivity was improved to 0.02 mg/(g x h). The apparent cell yield on glycerol and methanol were respectively 0.69 g/g and 0.93 g/g, higher than those in the fermentation without using the feeding strategy with dissolved oxygen as the indicator of metabolism.
Angiostatins ; genetics ; metabolism ; physiology ; Biotechnology ; methods ; Carbon ; metabolism ; Fermentation ; physiology ; Glycerol ; metabolism ; Methanol ; metabolism ; Oxygen ; metabolism ; Pichia ; genetics ; metabolism

The aim of this study was to find new idea for clinical treatment of aplastic anemia. Immune-mediated aplastic anemia mice were developed, IL-3 in the supernatant with PHA stimulating splenic cells was detected by ELISA, semi-quantiting analysis of IL-3R was performed by point hybridization. The results showed that the IL-3 level in the supernatant with PHA stimulating splenic cells of immune-mediated aplastic anemia mice was higher than controls, difference between them was significant (P <0.001), while amount of IL-3 receptor by semi-quantiting analysis was lower than control significantly. In conclusion, the IL-3 receptor expression level is important for pathogenesis and treatment strategy of aplastic anemia.
Anemia, Aplastic ; immunology ; pathology ; Animals ; Bone Marrow ; pathology ; Interleukin-3 ; analysis ; Mice ; Mice, Inbred BALB C ; Mice, Inbred DBA ; RNA, Messenger ; analysis ; Receptors, Interleukin-3 ; analysis ; genetics

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.