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13. in microbial fermenters

Author

Aytekin, O, Gurhan, SID, Ohura, K, Imai, T, and Ongen, G

Subjects
fermenter, recombinant protein production, Human dipeptidyl peptidase IV, Spodoptera frugiperda (Sf9), microbial
Abstract

The human dipeptidyl peptidase IV (hDPPIV/CD26) is expressed as an immune response in some cancer cells as well as intestine and incretin metabolism, and deficiency of the enzyme leads to metabolic disorders. In the present study, recombinant hDPPIV/CD26 genes were expressed in baculovirus-insect cell systems in a 5-L stirred-tank fermenter. Because of the shear sensitivity of the insect cell line, production from insect cells should be performed in new-generation type bioreactors, which are commonly more expensive than microbial fermenters. To optimize the process, hydrodynamic parameters and oxygen consumption of Sf9 cells at 1.5 L and 3 L were monitored, and a certain amount of serum was added to the production medium to decrease shear and stabilize the growth of insect cells that normally do not need serum addition. In this study, dimensionless numbers and some hydrodynamic parameters were calculated in 1.5 L, and predictions were made for 3 L fermenter volumes. Agitation rates of 60 rpm were determined to protect insect cells against damaging shear stress. Regarding the agitation rate, oxygen mass transfer coefficient (k(L)a) was 0.0129 min(-1) for 1.5 L and was kept constant for 3 L (0.0133 min(-1)). The maximum enzyme activity from microbial fermenters was 2.37-fold higher than activity from T-flask in our previous work. The infection efficiency of transfected cells was 78%-81% in the 1.5-L and 3-L fermenters.

Published
2016

14. Monitoring of the effects of transfection with baculovirus on Sf9 cell line and expression of human dipeptidyl peptidase IV

Author

Ustün-Aytekin O, Gürhan ID, Ohura K, Imai T, and Ongen G

Subjects
viruses
Abstract

Human dipeptidylpeptidase IV (hDPPIV) is an enzyme that is in hydrolase class and has various roles in different parts of human body. Its deficiency may cause some disorders in the gastrointestinal, neurologic, endocrinological and immunological systems of humans. In the present study, hDPPIV enzyme was expressed on Spodoptera frugiperda (Sf9) cell lines as a host cell, and the expression of hDPPIV was obtained by a baculoviral expression system. The enzyme production, optimum multiplicity of infection, optimum transfection time, infected and uninfected cell size and cell behavior during transfection were also determined. For maximum hDPPIV (269 mU mL(-1)) enzyme, optimum multiplicity of infection (MOI) and time were 0.1 and 72 h, respectively. The size of infected cells increased significantly (P < 0.001) after 24 h post infection. The results indicated that Sf9 cell line was applicable to the large scale for hDPPIV expression by using optimized parameters (infection time and MOI) because of its high productivity (4.03 mU m L(-1) h(-1)).

Published
2014

27. Development of intra-arterial hyperthermia using a dextran-magnetite complex

Author

Mitsumori, M., primary, Hiraoka, M., additional, Shibata, T., additional, Okuno, Y., additional, Masunaga, S., additional, Koishi, M., additional, Okajima, K., additional, Nagata, Y., additional, Nishimura, Y., additional, Abe, M., additional, Ohura, K., additional, Hasegawa, M., additional, Nagae, H., additional, and Ebisawa, Y., additional

Published
1994
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37. PORPHYROMONAS GINGIVALIS LIPOPOLYSACCHARIDE SIGNALING IN GINGIVALFIBROBLASTS- CD14 AND TOLL-LIKE RECEPTORS.

Author

Wang, P.-L. and Ohura, K.

Subjects
PORPHYROMONAS gingivalis infections, ENDOTOXINS, MICROBIAL polysaccharides, FIBROBLASTS, PERIODONTAL disease, PORPHYROMONAS gingivalis
Abstract

Periodontal disease is the major cause of adult tooth loss and is commonly characterized by a chronic inflammation caused by infection of oral bacteria. Porphyromonas gingivalis (P. gingivalis) is one of the suspected periodontopathic bacteria and is frequently isolated from the periodontal pockets of patients with chronic periodontal disease. The lipopolysaccharide (LPS) of P. gingivalis is a key factor in the development of periodontitis. Gingival fibroblasts, which are the major constituents of gingival connective tissue, may directly interact with bacteria and bacterial products, including LPS, in periodontitis lesions. It is suggested that gingival fibroblasts play an important role in the host responses to LPS in periodontal disease. P. gingivalis LPS enhances the production of inflammatory cytokines such as interleukin (IL)-1, IL-6, IL-8, and tumor necrosis factor alpha (TNF-a) in gingival fibroblasts. However, the receptor that binds with P. gingivalis LPS on gingival fibroblasts remained unknown for many years. Recently, it was demonstrated that P. gingivalis LPS binds to gingival fibroblasts. It was also found that gingival fibroblasts express CD14, Toll-like receptor 4 (TLR4), and myeloid differentiation primary response gene 88 (MyD88). P. gingivalis LPS treatment of gingival fibroblasts activates several intracellular proteins, including protein tyrosine kinases, and up-regulates the expression of monocyte chemoattractant protein-1 (MCP-1), extracellular signal-regulated kinase 1 (ERK1), and signal-regulated kinase 2 (ERK2), IL-1 receptor-associated kinase (IRAK), nuclear factor-kB (NF-kB), and activating protein-1 (AP-1). These results suggest that the binding of P. gingivalis LPS to CD14 and TLR4 on gingival fibroblasts activates various second-messenger systems. In this article, we review recent findings on the signaling pathways induced by the binding of P. gingivalis LPS to CD14 and Toll-like receptors (TLRs) in gingival fibroblasts. [ABSTRACT FROM AUTHOR]

Published
2002
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38. Effect of Streptozotocin Diabetes on Gingivitis in Plaque-susceptible Rats.

Author

TAKAI, N., SHINOHARA, M., YOSHIDA, Y., OHURA, K., MORI, M., and KAKUDO, Y.

Subjects
GINGIVITIS, PERIODONTAL pockets, STREPTOZOTOCIN, ENDOCRINE diseases, INCISORS, IMMUNOSUPPRESSIVE agents, DENTAL plaque
Abstract

The periodontal pocket probing depths of mandibular incisors of plaque-susceptible (Sus) rats, which spontaneously exhibit gingivitis with accumulation of plaque, were increased 20 days after injection of streptozotocin (70 mg/kg, i.v.). The accumulated plaque weights were also increased in Sus rats with streptozotocin diabetes, and a positive correlation was found between the plaque weights and the pocket depths. Histological findings showed that this inflammatory reaction in gingival tissue was higher and more extensive in diabetic Sus rats than in control Sus rats. These findings suggest that the accumulated plaque is the important factor for the severe breakdown of gingival tissue in this experimental model. [ABSTRACT FROM AUTHOR]

Published
1986
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39. Studies on saliva in ODU plaque-susceptible rats having experimental gingivitis.

Author

Ohura, K., Shinohara, M., Mori, M., Takai, N., Yoshida, Y., and Kakudo, Y.

Subjects
GINGIVITIS, SALIVA, RATS, SUBLINGUAL gland, DENTAL plaque, TEMPOROMANDIBULAR joint
Abstract

Saliva was collected from the submandibular, parotid, and sublingual glands at to compare the amount of saliva between ODU plaque-susceptible (Sus) and plaque-resistant (Res) rats. The amount of saliva secreted was less in the Sus rats than in the Res rats. This difference was mainly due to a decrease in salivation from the submandibular glands, which resulted from the decrease in the weight of these glands. This reduction in salivation may be associated with the rapid rate of plaque formation seen around the mandibular teeth of these animals and the development of periodontal diseases. [ABSTRACT FROM AUTHOR]

Published
1984
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41. Effect of Actinobacillus actinomycetemcomitansprotease on the proliferation of gingival epithelial cells

Author

Wang, P‐L, Azuma, Y, Shinohara, M, and Ohura, K

Abstract

OBJECTIVE: Actinobacillus actinomycetemcomitans(A. actinomycetemcomitans) has been implicated as an important pathogen in periodontal disease. The aim of this report is to examine the effect of in vitroapplication of A. actinomycetemcomitansprotease on the cell growth, DNA synthesis, and fibronectin level of human gingival epithelial cells.

Published
2001
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