• Journal of Life Science
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• v.17 no.8 s.88
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• pp.1129-1134
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• 2007

In the previous our study, a cDNA that encodes protein disulfide isomerase from Bombyx mori (bPDI)was isolated and characterized. bPDI has an open reading frame of 494 amino acids contained two PDI-typical thioredoxin active site of WCGHCK and ER (endoplasmic reticulum) retention signal of the KDEL motif at its C-terminal. Recent studies have demonstrated that misfolded proteins are accumulated in many diseases including Alzheimer’s, goiter, emphysema, and prion infections. bPDI was over-expressed or knock-downed in Sf9 cells to study the relationship between bPDI expression and protections against protein misfolding. bPDI gene was cloned in insect expression vector pIZT/V5-His for over-expression and bPDI double-stranded RNA (dsRNA) was generated for knock-down. Over-expression of bPDI significantly improved survival rate, but bPDI dsRNA transfection significantly reduced survival rate after 48 hours exposure. In mock-transfected or wild-type cells had no significant effect. The results support the view that bPDI is one of the important intracellular components for cell protect mechanism, especially, against ER stress such as protein misfolding.

• IMMUNE NETWORK
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• v.13 no.4
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• pp.148-156
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• 2013

The $PrP^C$ is expressed in many types of immune cells including monocytes and macrophages, however, its function in immune regulation remains to be elucidated. In the present study, we examined a role for $PrP^C$ in regulation of monocyte function. Specifically, the effect of a soluble form of $PrP^C$ was studied in human monocytes. A recombinant fusion protein of soluble human $PrP^C$ fused with the Fc portion of human IgG1 (designated as soluble $PrP^C$-Fc) bound to the cell surface of monocytes, induced differentiation to macrophage-like cells, and enhanced adherence and phagocytic activity. In addition, soluble $PrP^C$-Fc stimulated monocytes to produce pro-inflammatory cytokines such as $TNF-{\alpha}$, $IL-1{\beta}$, and IL-6. Both ERK and $NF-{\kappa}B$ signaling pathways were activated in soluble $PrP^C$-treated monocytes, and inhibitors of either pathway abrogated monocyte adherence and cytokine production. Taken together, we conclude that soluble $PrP^C$-Fc enhanced adherence, phagocytosis, and cytokine production of monocytes via activation of the ERK and $NF-{\kappa}B$ signaling pathways.

• Korean Journal of Veterinary Service
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• v.32 no.4
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• pp.307-314
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• 2009

The aim of the present study was to investigate whether Bovine Spongiform Encephalopathy (BSE) is present in this country and to analyze the Global BSE Risk (GBR) status in Bangladesh. A total of 2,000 brain samples were collected from cattle older than 30 months of age, slaughtered for human consumption in the district slaughter houses from 2005 to 2006. The brainstem (obex), Pyriform lobe, cerebrum and cerebellum were subjected to histopathological study. Samples that showed some nonspecific lesions were subjected to immunohistochemistry and only brain stem to ELISA for the detection of abnormal prion protein $PrP^{sc}$. In passive surveillance, annual overall diseases of cattle, buffalo, sheep and goats in Bangladesh were collected from Department of Livestock Services (DLS), Dhaka to investigate the occurrences of neurological diseases. Import related data were collected from "National Export Promotion Bureau" Kawran Bazar, Bangladesh Bank and DLS to analyze the importing products of animal origin (cattle, buffalo, sheep and goats) from different countries to find whether or not the imported products posed any risk for the BSE. In an actire surveillance conducted in slaughter house, histopathologically BSE specific lesions were not detected in any of the brain samples, but other nonspecific lesions were observed. No $PrP^{sc}$ was detected from the samples by immunohistochemistry and ELISA. DLS report also supported the absence of BSE in cattle and buffalo and scrapie in sheep and goats in Bangladesh. It was also clearly recorded that Bangladesh imported livestock products from countries in GBR level I and II but not from countries in GBR level III and IV. From this study it apparently seems that BSE is not currently present in the indigenous animals in Bangladesh and poses no or negligible risk to human and animal health.