• Development and Reproduction
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• 제28권2호
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• pp.29-36
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• 2024

Cellular prion protein (PrP^C) encoded at Prnp gene is well-known to form a misfolded isoform, termed scrapie PrP (PrP^SC) that cause transmissible degenerative diseases in central nervous system. The physiological role of PrP^C has been proposed by many studies, showing that PrP^C interacts with various intracellular, membrane, and extracellular molecules including mitochondrial inner membrane as a scaffold. PrP^C is expressed in most cell types including reproductive organs. Numerous studies using PrP^C knockout rodent models found no obvious phenotypic changes, in particular the clear phenotypes in development and reproduction have not demonstrated in these knockout models. However, various roles of PrP^C have been evaluated at the cellular levels. In this review, we summarized the known roles of PrP^C in various cell types and tissues with a special emphasis on those involved in reproduction.

• Biomolecules & Therapeutics
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• 제26권3호
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• pp.313-321
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• 2018

Anti-cancer drug resistance is a major problem in colorectal cancer (CRC) research. Although several studies have revealed the mechanism of cancer drug resistance, molecular targets for chemotherapeutic combinations remain elusive. To address this issue, we focused on the expression of cellular prion protein ($PrP^C$) in 5-FU-resistant CRC cells. In 5-FU-resistant CRC cells, $PrP^C$ expression is significantly increased, compared with that in normal CRC cells. In the presence of 5-FU, $PrP^C$ increased CRC cell survival and proliferation by maintaining the activation of the PI3K-Akt signaling pathway and the expression of cell cycle-associated proteins, including cyclin E, CDK2, cyclin D1, and CDK4. In addition, $PrP^C$ inhibited the activation of the stress-associated proteins p38, JNK, and p53. Moreover, after treatment of 5-FU-resistant CRC cells with 5-FU, silencing of $PrP^C$ triggered apoptosis via the activation of caspase-3. These results indicate that $PrP^C$ plays a key role in CRC drug resistance. The novel strategy of combining chemotherapy with $PrP^C$ targeting may yield efficacious treatments of colorectal cancer.

• IMMUNE NETWORK
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• 제13권4호
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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.

• BMB Reports
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• 제56권12호
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• pp.645-650
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• 2023

Numerous studies have investigated the cellular prion protein (PrP^C) since its discovery. These investigations have explained that its structure is predominantly composed of alpha helices and short beta sheet segments, and when its abnormal scrapie isoform (PrPSc) is infected, PrPSc transforms the PrP^C, leading to prion diseases, including Creutzfeldt-Jakob disease in humans and bovine spongiform encephalopathy in cattle. Given its ubiquitous distribution across a variety of cellular types, the PrP^C manifests a diverse range of biological functions, including cell-cell adhesion, neuroprotection, signalings, and oxidative stress response. PrP^C is also expressed in immune tissues, and its functions in these tissues include the activation of immune cells and the formation of secondary lymphoid tissues, such as the spleen and lymph nodes. Moreover, high expression of PrP^C in immune cells plays a crucial role in the pathogenesis of prion diseases. In addition, it affects inflammation and the development and progression of cancer via various mechanisms. In this review, we discuss the studies on the role of PrP^C from various immunological perspectives.

• Journal of the Korean Chemical Society
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• 제37권1호
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• pp.98-104
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• 1993

The paramagnetic organoruthenium(III) complexes $({\eta}^5-C_5Me_5)RuCl_2(PR_3) (PR_3 = PMe_3,\;PEt_3,\;PiPr_3,\;PCy_3,\;PMe_2Ph,\;PMePh_2,\;PPh_3,\;P(p-C_6H_4CH_3)_3$, DPPE, DPPB, Py) (2a∼2k) were synthesized by the reaction of $[({\eta}^5-C_5Me_5)RuCl_2]_2$ (1) with 1 equivalent of the corresponding phosphines $(PR_3)$. The effective magnetic moment ((${\mu}_{eff} = 1.65∼2.07 B.M.$)) derived from the magnetic susceptibility measurements of the complexes (2a∼2k) were consistent with the presence of a "single" unpaired electron in the molecule. Treatment of dichlororuthenium (III) complex ({\eta}^5-C_5Me_5)RuCl_2(PR_3)$ (2) (i) with KBr in acetone afforded the dibromoruthenium (III) complex $({\eta}^5-C_5Me_5)RuBr_2(PR_3) (PR_3 = PPh_3)$, (ii) with sodium amalgam in diethylether led to the bis(phosphine) derivatives $({eta}^5-C_5Me_5)RuCl(PR_3)_2 (PR_3 = PMe_3,\;PMePh_2)$, and (iii) with carbonmonoxide gave to the carbonyl derivatives $({\eta}^5-C_5Me_5)RuCl(PR_3)(CO) (PR_3 = PMe_3,\;PPh_3)$.

• Journal of Microbiology and Biotechnology
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• 제27권5호
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• pp.1023-1031
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• 2017

The conformational change of cellular prion protein ($PrP^C$) to its misfolded counterpart, termed $PrP^{Sc}$, is mediated by a hypothesized cellular cofactor. This cofactor is believed to interact directly with certain amino acid residues of $PrP^C$. When these are mutated into cationic amino acid residues, $PrP^{Sc}$ formation and prion replication halt in a dominant negative (DN) manner, presumably due to strong binding of the cofactor to mutated $PrP^C$, designated as DN PrP mutants. Previous studies demonstrated that plasminogen and its kringle domains bind to PrP and accelerate $PrP^{Sc}$ generation. In this study, in vitro binding analysis of kringle domains of plasminogen to Q167R DN mutant PrP (PrPQ167R) was performed in parallel with the wild type (WT) and Q218K DN mutant PrP (PrPQ218K). The binding affinity of PrPQ167R was higher than that of WT PrP, but lower than that of PrPQ218K. Scatchard analysis further indicated that, like PrPQ218K and WT PrP, PrPQ167R interaction with plasminogen occurred at multiple sites, suggesting cooperativity in this interaction. Competitive binding analysis using $\small{L}$-lysine or $\small{L}$-arginine confirmed the increase of the specificity and binding affinity of the interaction as PrP acquired DN mutations. Circular dichroism spectroscopy demonstrated that the recombinant PrPs used in this study retained the ${\alpha}$-helix-rich structure. The ${\alpha}$-helix unfolding study revealed similar conformational stability for WT and DN-mutated PrPs. This study provides an additional piece of biochemical evidence concerning the interaction of plasminogen with DN mutant PrPs.

• Microbiology and Biotechnology Letters
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• 제43권2호
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• pp.91-96
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• 2015

Prions are proteinaceous infectious particles that cause neurodegenerative diseases, such as scrapie in sheep, bovine spongiform encephalopathy in cattle and Creutzfeldt-Jakob disease (CJD) in humans. Although the detailed process, regarding the abnormal conversion of prion proteins (PrP), remains to be fully elucidated, a number of environmental factors appear to affect the formation of misfolded PrP, termed PrP^Sc. Because oceanic algae contain mycosporine-like amino acids (MAAs), which exhibit cellular defensive activities under a variety of stress conditions, we investigated the level of PrP^Sc in prion-infected neuroblastoma cells using mycosporine-glycine, porphyra-334 and shinorine. When judged by the level of protease-resistant PrP^Sc in western blots, porphyra-334 and shinorine increased the level of PrP^Sc in cells, but mycosporine-glycine did not. The current results indicate that the MAAs tested in this study enhance the formation of PrP^Sc.

• Korean Journal of Microbiology
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• 제17권3호
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• pp.97-130
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• 1979

Many industrial processes those employ bacteria are subjected to phage infestations. In L-glutamic acid fermentions using acetic acid, the phage infestations of the organisms have been recently recognized. In efforts to elucidate the sources of phage contamination involved in the abnormal fermentation, a series of study was conducted to isolate the phages both from the contents of abnormally fermented tanks and the soil or sewage samples from the surroundings of a fermentation factory, to define major charateristics of the phage isolates, and finally to determine the correlation between the phage isolates and temperate phages originating from the miscellaneous bacterial species isolated from the soil or sewage samples. The results are summarized as follows; 1) All phages were isolated from the irregular fermentation tanks and soil or sewage samples, and they were designated as phage PR-1, PR-2, PR-3, PR-4, PR-5, PR-6, and PR-7, in the order of isolation. These PR-series phages were proved to be highly specific for the variant strains of Br. lactofermentum only, namely, phage PR-1 and PR-2 for Br. lactofermentum No. 468-5 and phage PR-3~PR-7 for Br. lactofemrentum No. 2256. By cross-neutralization test, the 7 phagescould be subdivided into 3 groups, i. e., phage PR-I and PR-2 the first, phage PR-3, PR-4, PR-5, PR-6 the second, and the phage PR-7 the third. 2) The 7 phages were virulent under the experimental conditions. They produced plaques with clear and relatively sharp margins without distinct halo. The mean sizes of plaques were 1.5mm in diameter for phage PR-1 and PR-2, and 1. Omm for phages PR-3~PR-7. Double layer technique modified by Hongo and described by Adams, was applied to assay of the PR-series phages. The factors influencing the plaques were as follows;young age cells of host bacteria cultured for 3-6 hours represented the largest number and size, optimum was pH 7.0, incubation temperature was $30^{\circ}C$, and agar concentration and amount of overlayer medium were 0.6% and 0.2ml, respectively. 3) PR-series phages were stable in 0.05M tris buffer and 0.1M ammonium acetate buffer solution. The addition of $5{\times}10^{-3}M$ magnesium ion effectively increased the stability. Thermostability experiments indicated that PR-series phages were stable at the teinperture between $50^{\circ}{\sim}55^{\circ}C$ in nutrient medium, $45^{\circ}{\sim}50^{\circ}C$ in buffer solution. However, the phages mere completely inactivated at 603C and 65$^{\circ}$C within 10 minutes. The phages were stable at the range of pH6~9 in nutrient medium and of pH 8-9 in buffer solution, respectively. Exposure of the phages to UV for 25, 60 and 100 seconds resulted in the complete loss of infectivily, respectively. 4) Electron microscopy showed that PR-series phage particles exhibited rather similar morphology, differing in the size All of PR-series phages had a multilateral head and had a simple long tiil about three to five times long as compared with head. By the size, phage PR-1 and PR-2, PR-3, PR-4, PR-5, and PR-6 and PR-7 were classified into same groups, respectively. The head and tail size of phage PR-1, PR-5, PR-5(T) and PR-7 were 85nm, 74nm and 235nm and 350mm, and 72nm and 210nm, respectively. 5) Nucleic acids of PR-series phages were double stranded DNA. The G+C contents of phage PR-1, PR-5 and PR-7 were 56.1, 52.9 and 53.7, respectively. The values of G+C contents derived from the $T_m$ were in agreement with the chemically determined values. 6) PR-series phages effectively adsorbed on their host bacteria at the rate of more than 90% during 5 min. K value for phage PR-1, PR-5 and PR-7 were calculated to be $6{\times}10^9 ml$ per minute, respectiveky. The pH of the medium did effect adsorption rate, but both temperature and age of host cells did not. Generally, optimum adsorption condition of phages seemed to be almost same as optimum growth conditions of host bacteria. 7) In one-step growth experiments, the latent periods at $30^{\circ}C$ for PR-1, and PR-7 were about 70, 50 and 55 min, respectively. The corresponding average burst size was 200, 70 and 90, respectively. Lpsis period according to the multiplicity of infection and a phage series. In case of m. o. i. 100, strain No. 2256 (PR-5) and No. 468-5(PR-1) failed to grow and turbidity decreased after 50 and 70min, respectively. 8) In the lysate of a plaque purified phage PR-5 infected bacteria, there observed 2 types ofphage particles, i. e., phage PR-5 and PR-5 (T) of similar morphology but differing at the length of phage tail, and phage tail like particles. The phage taillike particles could be divided into 4 types by the length. Induction experiments of Br. lactofermentum with UV irradiation, mitomycin C or bacitracin treatment produced neither phage PR-5 (T) or phage tail-like particles. 9) No lysis occured when the growth of 7 strains of miscellaneous bacteria, isolated from soil and sewage samples, were inoculated with either phage PR-5 (T) or phage tail-like particles the inoculation of phage PR-5 pellet resulted in the growth inhibition of the orgainsms in the spot test. The lysates obtained from 3 miscellaneous soil derived bacteria following mitomycin C treatment the growth of Br. lactofermentum, but did not lyze the bacterium.

• Korean Journal of Clinical Laboratory Science
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• 제36권2호
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• pp.185-192
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• 2004

Overexpressions of the estrogen receptors(ER), progesterone receptors(PR) and C-erbB-2 protein are important determiners of the response to chemotherapy in the breast cancer. For detecting ER, PR and C-erbB-2, immunohistochemistry are currently regarded as standard method. The purposes of this study compared to histologic grade and expression of the ER, PR and C-erbB-2 in breast cancer. We examined overexpression of ER, PR and C-erbB-2 protein in 84 breast carcinomas by using immunohistochemical stains. The following results were obtained. For histologic grade, 10 cases(11.9%) showed carcinoma in situ, 16 cases(19%) showed grade I, 36 cases (42.9%) showed grade II, and 22 cases(26.2%) showed grade III among the 84 test samples. The average positive rate ER and PR was 63%, 46% showed carcinoma in situ, 80%, 60% showed grade I, 64%, 41% showed grade II, 34%, 23% showed grade III, respectively. The induction of PR increased when induction of ER increased, thus showing significant relationship(p<0.05). The expression of C-erbB-2 protein was 9 cases(10.7%) in one positive(1+), 9 cases(10.7%) in two positive(2+), and 9 cases(10.7%) in three positive(3+). C-erbB-2 protein expression showed no statistical significance. In conclusion, ER and PR positive rates were inversely associated with histologic grades significantly(p<0.05). C-erbB-2 showed no significant difference with histologic grade. However ER, PR and C-erbB-2 showed significant relationship with each other(p<0.05). Therefore, these findings might be an important prognostic factor and might be arranged as a regular pathological examination in cases of breast cancer.

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6789-6794
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• 2015

Background: To analyze the expression of estrogen receptors (ER), progesterone receptors (PR), C-erbB-2 and Ki-67 in endometrial carcinoma (EC) and their relationships with the clinicopathological features. Materials and Methods: Sixty-seven EC samples, 53 normal endometrial samples and 53 atypical hyperplasia endometrial samples were all selected in Shaanxi Provincial People's Hospital from Jun., 2012 to Jun., 2014. The expression of ER, PR, C-erbB-2 and Ki-67 in EC tissue, normal endometrial tissue and atypical hyperplasia endometrial tissue was respectively detected using immunohistochemical SP method. The relationships between the expression of ER, PR, C-erbB-2 and Ki-67 and the patients' clinicopathological features as well as their correlations in EC tissue were also analyzed. Results: The positive expression rates of ER and PR in EC tissue were 44.8% and 41.8%, respectively, dramatically lower than in atypical hyperplasia endometrial tissue and normal endometrial tissue (P<0.01). The positive expression rates of C-erbB-2 and Ki-67 in EC tissue were 80.6% and 64.2%, respectively, significantly higher than in atypical hyperplasia endometrial tissue and normal endometrial tissue (P<0.01). In EC tissue, the expression of ER and PR was closely associated with the differentiated degrees and depth of myometrial invasion (P<0.05), while that of C-erbB-2 and Ki-67 with the clinical staging, differentiated degrees, depth of myometrial invasion and presence or absence of lymph node metastasis (P<0.05). Spearman correlation analysis further displayed that the expression of ER was positively correlated with PR (r=0.393, P=0.001), but negatively with C-erbB-2 and Ki-67 (r=-0.469, P=0.000; r=-0.329, P=0.007); The expression of PR was negatively correlated with C-erbB-2 and Ki-67 (r=-0.273, P=0.025; r=-0.251, P=0.041), but that of C-erbB-2 positively with Ki-67 (r=0.342, P=0.005). Conclusions: Abnormal expression of ER, PR, C-erbB2 and Ki-67 might play an important role in endometrial malignant transformation and cell differentiation, so their joint detection is likely to be a comprehensive combination of immune factors, which is of great importance for EC prognosis.