Objective To develop a procedure for large scale fermentation and purification of recombinant human uPA17-KPI (rhuPA17-KPI)in Pichia pastoris in 80 L fermenter. Methods The pH value for expression of rhuPA17-KPI in P. pastoris was opti-mized. Two liters of recombinant P. pastoris seeds for expression of rhuPA17-KPI were prepared in shake-flask and inoculated into a 80 L fermenter for high density fermentation by fed batch at the optimal pH value. Various conditions were controlled and optimized, based on which the fermentation was completed after induction with methanol for 48 h. The fermentation liquid was centrifuged then purified by SP Sepharose XL cation exchange chromatography and SourceTM 30 RPC reverse phase hydrophobic column chromatography. Results A procedure for fermentation was developed as follows: the temperature for fermentation was controlled at 28 ℃, the pH value at 5. 5, and the DO at 25% ～ 30%. The induction with methanol was started when the wet weight of the yeast cells reached 190g / L. The secretion level of rhuPA17-KPI reached a peak value of 300 mg / L fermentation liquid 30 h after induction. The rhuPA17-KPI with a purity of more than 95% was obtained for purification of fermentation supernatant by SP Sepharose XL cation exchange chromatogra-phy and SourceTM 30 RPC reverse phase hydrophobic column chromatography, of which the yield and recovery rate were 180 mg / L and 60% respectively. Conclusion A procedure for large scale fermentation and purification of rhuPA17-KPI in Pichia pastoris in 80 L fermenter was successfully developed, which laid a foundation of industrialization and application of rhuPA17-KPI.
Esophageal squamous cell carcinoma accounts for a large proportion of cancer-associated mortalities in both men and women. Melittin is the major active component of bee venom, which has been reported to possess anti-inflammatory, antibacterial and anti-cancer properties. The aim of the present study was to construct a tumor targeted recombinant plasmid [pc-telomerase reverse transcriptase (TERT)-melittin] containing a human TERT promoter followed by a melittin coding sequence and to explore the effects of this plasmid in esophageal cell carcinoma and investigate preliminarily the underlying mechanisms of this effect. TE1 cells were transfected with pcTERT-melittin and the resulting apoptosis was subsequently examined. The viability of TE1 cells transfected with pcTERT-melittin was measured using a Cell Counting Kit-8 assay, which indicated inhibited proliferation. The disruption of mitochondrial membranes and the concomitant production of reactive oxygen species demonstrated an inducible apoptotic effect of melittin in TE1 cells. Apoptotic cells were also counted using an Annexin V-FITC and PI double-staining assay. The upregulation of cleaved caspase-9, cleaved caspase-3, Bax and poly(ADP-ribose) polymerase 1 in pcTERT-melittin transfected TE1 cells, suggested that pcTERT-melittin-induced apoptosis was associated with the mitochondrial pathway. TE1 cells were also arrested in the G0/G1 phase when transfected with pcTERT-melittin, followed by the decline of CDK4, CDK6 and cyclin D1 expression levels. As cell invasion and metastasis are common in patients with esophageal cancer, a cell migration assay was conducted and it was found that pcTERT-melittin transfection reduced the migratory and invasive abilities of TE1 cells. The findings of the present study demonstrated that pcTERT-melittin may induce apoptosis of esophageal carcinoma cells and inhibit tumor metastasis.
With significant high incidence and death rates, liver cancer has become one of the most common cancers all over the world. Hence, novel strategies are needed for the management of this malignancy. Apoptotic related proteins Noxa and Puma are the members of BH3-only family. In this study, human Noxa or Puma coding sequences have been inserted into plasmid pcDNA 3.1 regulated by human TERT promoter. The transfection of HepG2 cells with pcTERT-Noxa or pcTET-Puma resulted in the significant suppression of cell proliferation as well as finally led to apoptosis via mitochondrial and death receptor pathways, and also exhibited significantly reduced the ability of invasion and metastasis. Moreover, an in vivo study revealed that intratumoral injections of pcTERT-Noxa or pcTERT-Puma plasmids effectively suppressed the tumor growth and can exhibit anti-neoplastic effects by recruiting CD3, CD8, CD45 positive T lymphocytes in the tumor tissues. Overall, our findings illustrated that pcTERT-Noxa and pcTERT-Puma may exhibit significant anti-tumor effects both in vivo and in vivo.
Effects of thyroid hormone on proteoglycan degradation in various regions of cartilage were investigated. In propylthiouracil-treated rats with hypothyroidism, proteoglycan degradation in epiphyseal cartilage during endochondral ossification was markedly suppressed. However, injections of T(4) reversed this effect of propylthiouracil on proteoglycan degradation. In pig growth plate explants, T(3) also induced breakdown of proteoglycan. T(3) increased the release of aggrecan monomer and core protein from the explants into the medium. Accordingly, the level of aggrecan monomer remaining in the tissue decreased after T(3) treatment, and the monomer lost hyaluronic acid-binding capacity, suggesting that the cleavage site is in the interglobular domain. The aggrecan fragment released from the T(3)-exposed explants underwent cleavage at Glu(373)-Ala(374), the major aggrecanase-cleavage site. The stimulation of proteoglycan degradation by T(3) was less prominent in resting cartilage explants than in growth plate explants and was barely detectable in articular cartilage explants. Using rabbit growth plate chondrocyte cultures, we explored proteases that may be involved in T(3)-induced aggrecan degradation and found that T(3) enhanced the expression of aggrecanase-2/ADAM-TS5 (a disintegrin and a metalloproteinase domain with thrombospondin type I domains) mRNA, whereas we could not detect any enhancement of stromelysin, gelatinase, or collagenase activities or any aggrecanase-1/ADAM-TS4 mRNA expression. We also found that the aggrecanse-2 mRNA level, but not aggrecanase-1, increased at the hypertrophic stage during endochondral ossification. These findings suggest that aggrecanse-2/ADAM-TS5 is involved in aggrecan breakdown during endochondral ossification, and that thyroid hormone stimulates the aggrecan breakdown partly via the enhancement of aggrecanase-2/ADAM-TS5.
Formaldehyde inhalation exposure, which can occur through occupational exposure, can lead to sensory irritation, neurotoxicity, mood disorders, and learning and memory impairment. However, its influence on olfactory function is unclear.To investigate the mechanism and the effect of repeated formaldehyde inhalation exposure on olfactory function.Rats were treated with formaldehyde inhalation (13·5±1·5 ppm, twice 30 minutes/day) for 14 days. Buried food pellet and locomotive activity tests were used to detect olfactory function and locomotion. Western blots were used to evaluate synaptosomal-associated protein 25 (SNAP25) protein levels in the olfactory bulb (OB) lysate and synaptosome, as well as mature and immature olfactory sensory neuron markers, olfactory marker protein (OMP), and Tuj-1. Real-time polymerase chain reaction (PCR) was used to detect SNAP25 mRNA amounts.Repeated formaldehyde inhalation exposure impaired olfactory function, whereas locomotive activities were unaffected. SNAP25 protein decreased significantly in the OB, but not in the occipital lobe. SNAP25 also decreased in the OB synaptosome when synaptophysin did not change after formaldehyde treatment. mRNA levels of SNAP25A and SNAP25B were unaffected. Mature and immature olfactory sensory neuron marker, OMP, and Tuj-1, did not change after formaldehyde treatment.Repeated formaldehyde exposure impaired olfactory function by disturbing SNAP25 protein in the OB.
To investigate the effects of hyaluronic acid (HA) on the release of proteoglycan by cultured rabbit chondrocytes.Articular cartilage chondrocytes were isolated from the knee joints of New Zealand white rabbits. Proteoglycan synthesis after incubation with HA was determined by measuring 35S-sulfate incorporation. Cells incubated with HA were labeled with 3H-glucosamine and applied to a Sepharose CL-2B column. After incubation of confluent cells with 35S-sulfate and then with HA in various concentrations in the presence or absence of cytokines, proteoglycan release from the cell matrix layer was measured.HA (M(r) 3 x 10(5) to 19 x 10(5)), at 10 micrograms/ml to 1 mg/ml, had little effect on the incorporation of 35S-sulfate or 3H-glucosamine into cartilage matrix proteoglycans, or on the hydrodynamic size of proteoglycan monomers, in rabbit chondrocyte cultures. However, at 10-1,000 micrograms/ml, HA suppressed the release of 35S-proteoglycans from the cell matrix layer into the medium in the presence and absence of interleukin-1, tumor necrosis factor alpha, or basic fibroblast growth factor.These results suggest that HA is a potent inhibitor of the displacement of matrix proteoglycan into culture medium.
AbstractThe effect of non-steroidal anti-inflammatory drugs (NSAIDs) on rabbit articular chondrocyte proliferation was examined in soft agarand in conventional cultures on plastic dishes. Indomethacin, acetylsalicylate, and naproxen (10−4 M) decreased the efficiency of colony formation by chondrocytes in soft agar in the presence of fibroblast growth factor, although the drugs had little effect on the proliferation of chondrocytes on plastic dishes. On the other hand, tiaprofenic acid (10−4 M) did not have any adverse effect on chondrocyte replication in either culture the two systems.Rabbit articular chondrocyte growth in soft agar will be a useful test system for examining the effects of anti-arthritic drugs on cartilage metabolism and repair.Key Words: chondrocyte cultureanti-arthritic drugs
Objective To construct a cDNA library by using mRNA from Gloydius ussuriensis(G. ussuriensis) venom gland, to clone and analyze serine proteinase gene from the cDNA library. Methods Total RNA was isolated from venom gland of G. ussuriensis, mRNA was purified by using mRNA isolation Kit. The whole length cDNA was synthesized by means of smart cDNA synthesis strategy, and amplified by long distance PCR procedure, lately cDAN was cloned into vector pBluescript-sk. The recombinant cDNA was transformed into E.coli DH5α. The cDNA of serine proteinase gene in the venom gland of G. ussuriensis was detected and amplified using the in situ hybridization. The cDNA fragment was inserted into pGEMT vector, cloned and its nucleotide sequence was determined. Results The capacity of cDNA library of venom gland was above 2.3×10 6. Its open reading frame was composed of 702 nucleotides and coded a protein pre-zymogen of 234 amino acids. It contained 12 cysteine residues. The sequence analysis indicated that the deduced amino acid sequence of the cDNA fragment shared high identity with the thrombin-like enzyme genes of other snakes in the GenBank. The query sequence exhibited strong amino acid sequence homology of 85% to the serine proteas of T. gramineus, thrombin-like serine proteinase Ⅰ of D. acutus and serine protease catroxase Ⅱ of C. atrox respectively. Based on the amino acid sequences of other thrombin-like enzymes, the catalytic residues and disulfide bridges of this thrombin-like enzyme were deduced as follows: catalytic residues, His 41 ,Asp 86 , Ser 180 ; and six disulfide bridges Cys 7 -Cys 139 , Cys 26 -Cys 42 , Cys 74 -Cys 232 , Cys 118 -Cys 186 , Cys 150 -Cys 165 , Cys 176 -Cys 201 . Conclusion The capacity of cDNA library of venom gland is above 2.3×10 6, overtop the level of 10 5 capicity, The constructed cDNA library of G. ussuriensis venom gland would be helpful platform to detect new target genes and further gene manipulate. The cloned serine proteinase gene exhibits strong amino acid sequence homology of 85% to the serine proteas of T. gramineus, thrombin-like serine proteinase Ⅰ of D. acutus and serine protease catroxase Ⅱ of C. atrox respectively.
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